readme grub4dos

Please refer to http://grub4dos.sourceforge.net/wiki/ for DOCs on GRUB4DOS.

Main project page: http://grub4dos-chenall.googlecode.com/

Download site: http://code.google.com/p/grub4dos-chenall/downloads/list

Unused:Download site: http://grub4dos.sourceforge.net/Download site: http://sarovar.org/projects/grub4dos/Download site: http://grub4dos.nufans.net/Download site: http://sites.google.com/site/grubdos/Download site: ftp://grub4dos.sarovar.org/pub/grub4dos/

Get the latest source code by using anonymous svn in this way:

svn co http://grub4dos-chenall.googlecode.com/svn/trunk/ grub4dos

or in this way:

git clone git://github.com/chenall/grub4dos.git

View the source code online with your web browser at:

http://code.google.com/p/grub4dos-chenall/source/browse/

GRUB4DOS mailing list:

[email protected]

Subscription page:

https://mail.gna.org/listinfo/grub4dos-devel/

Discussion forum(Official technical support site):

Chinese:http://bbs.wuyou.com/forumdisplay.php?fid=60http://bbs.znpc.net/forumdisplay.php?fid=4English:http://reboot.pro/forum/66/

********************************************************************************* GCC Blacklist *********************************************************************************

It is known that gcc-4.6.x creates binaries which fails to work on certain machines.Source: http://bbs.wuyou.net/viewthread.php?tid=274070 [Chinese GBK]

It is known that gcc-4.7.x creates binaries which fails to start memtest86.Source: http://bbs.wuyou.net/redirect.php?tid=180142&pid=2669810&goto=findpost#pid2669810 [Chinese GBK]

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Usage:GRUB [--bypass] [--time-out=T] [--hot-key=K] [--config-file=FILE

]

The FILE, for example, can be (hd0,0)/menu.lst

In CONFIG.SYS, the line looks like:

install=c:\some\where\grub.exe --config-file=FILE

If no options present, GRUB.EXE simply uses

(hd0,0)/menu.lst

as the configure file, if it exists. (Notice! We finallychanged the default file from (hd0,0)/boot/grub/menu.lst to(hd0,0)/menu.lst) (Changed 2006-12-23. See Update 3 below.)

The partition (hd0,0) can be of a Windows partition or a Linuxpartition, or any other partition type supported by GRUB.

Only GRUB-style filename is acceptable here for FILE. A DOSfilename won't work(it is certain we should use GRUB-stylefilenames because DOS-filenames won't access a file in aLinux ext2 partition for example).(See Update 2 below)

Update: FILE can be the contents of a menu. Use semi-colonto delimitate the embedded commands here in FILE. The FILEcan be enclosed with a pair of double-quotes. For example:

GRUB --config-file="root (hd0,0);chainloader +1"

This command will boot the system in (hd0,0).

Another example:

GRUB --config-file="reboot"

This command will reboot the machine.

One more example:

GRUB --config-file="halt"

This command will halt the machine.

if --bypass is specified, GRUB will exit to DOS whentimeout reached.

The option `--time-out=T' specifies the timeout value inseconds. T defaults to 5 if --bypass is specified and defaultsto 0 if --bypass is not specified.

The default hot key value is 0x3920(for space bar). If thiskey is pressed, GRUB will boot normally. If another key ispressed, GRUB will terminate immediately and return back toDOS. See "int 16 keyboard scan codes" below.

Each option can be specified only once at most.

Update 2: DOS filenames have been supported(patched by JohnCobb). If the beginning two characters of FILE are "#@", thenthe rest of FILE is taken as a DOS filename. Example:

GRUB --config-file="#@c:\menu.lst"

Only the beginning 4KB of the DOS file will be used. The fileshould be an uncompressed text file.

Note: You may also use the `direct DOS file access' with theSHELL or INSTALL line in CONFIG.SYS, but should not use itwith the DEVICE line. The DOS document said that a DOS devicedriver should not call the `open file' DOS call.

Update 3(2006-12-23): By default, GRUB.EXE will locate itsconfig file in the following order:

(DOS file) .\menu.lst, the MENU.LST in the current dir.

(DOS file) \menu.lst, the MENU.LST in the root dir ofthe current drive.

(GRUB file) /menu.lst, the MENU.LST in the root dir ofthe boot device.

The default boot device is still (hd0,0).

--------------------------------------------------------

Update 1: Version 0.2.0 also brings out a new thing, GRUB for NTLDR,which could be used to boot into GRUB from the boot menuof Windows NT/2000/XP. Copy GRLDR to the root directory ofdrive C: of Windows NT/2000/XP and append to C:\BOOT.INIthis line:

C:\GRLDR="Start GRUB"

That will be done. The GRLDR should be in the same directoryas BOOT.INI and NTLDR. Note that BOOT.INI is usually hiddenand you must unhide it before you can see it. The filenameGRLDR shouldn't be changed. If GRLDR is in a NTFS partition,it should be copied to the root directory of another non-NTFSpartition(and likewise should the menu.lst file be). If GRLDRis compressed, e.g., in a NTFS partition, it will not work.

Even if the drive letter of this disk has been changed toother than C by the Windows device manager, it seems you stillhave to use the letter C here in BOOT.INI, otherwise, NTLDRwill fail to locate the GRLDR file.

And what's more, if you are booting NTLDR from a floppy, youwill have to write the GRLDR line in A:\BOOT.INI like this:

C:\GRLDR="Start GRUB"

and shouldn't use the letter A like this:

A:\GRLDR="Start GRUB"

(Note that in the case when BOOT.INI is on floppy A, thenotation "C:\GRLDR" actually refer to the file A:\GRLDR).

Update 2: GRUB for Linux is also introduced along with 0.2.0. You canboot grub using a linux loader KEXEC, LILO, SYSLINUX or another

GRUB. (GRUB4LIN has merged into GRUB.EXE)

To boot GRUB off Linux, use this pair of commands:

kexec -l grub.exekexec -e

To boot GRUB via GRUB, use commands like the following:

kernel (hd0,0)/grub.exeboot

To boot GRUB via LILO, use these lines in lilo.conf:

image=/boot/grub.exelabel=grub.exe

To boot GRUB via SYSLINUX, use these lines in syslinux.cfg:

label grub.exekernel grub.exe

LOADLIN may encounter problems when loading grub.exe, becausegrub.exe requires some unchanged original BIOS interruptvectors, but DOS has destroyed them, and loadlin does notrecover them before it transfers control to grub.exe.

Update 3: Beginning at version 0.4.0, GRUB for DOS supports memdrives.Example:

# boot into a floppy imagemap --mem (hd0,0)/floppy.img (fd0)map --hookchainloader (fd0)+1rootnoverify (fd0)map --floppies=1boot

Because the image will be copied to a memory area, the imageitself can be non-contiguous and even gzipped.

Another Example:

map --mem=-2880 (hd0,0)/floppy.img (fd0)

This memdrive (fd0) will occupy at least 1440 KB of memory.This is useful when the size of a 1.44M-floppy image is lessthan 1440 KB.

One more example:

map --mem --read-only (hd0,0)/hd.img (hd1)

This memdrive is a hard drive, and read-only. That means youwill not be able to write data to the memdrive (hd1).

You can use many memdrives and many ordinary virtual emulateddisk-based drives at the same time.

If the BIOS does not support int15/EAX=e820h, you will not be

able to use any memdrives.

Update 4: For memdrive emulation, a single-partition image can be usedinstead of a whole-harddrive image. Example:

map --mem (hd0,7)/win98.img (hd0)map --hookchainloader (hd0)+1rootnoverify (hd0)map --harddrives=1boot

Here win98.img is a partition image without the leading MBRand partition table in it. Surely GRUB for DOS will build anMBR and partition table for the memdrive (hd0).

Update 5: Now GRLDR can be used as a no-emulation-mode bootable CD-ROMboot image. Example for Linux users:

mkdir iso_rootcp grldr iso_rootmkisofs -R -b grldr -no-emul-boot -boot-load-seg 0x1000

-o bootable.iso iso_root

As an alternative, grldr can also be used the same way asstage2_eltorito. The -boot-info-table option is allowed but youcan omit it:

mkdir iso_rootcp grldr iso_rootmkisofs -R -b grldr -no-emul-boot -boot-load-size 4 -o g

rldr.iso iso_root

Also note that the bootable.iso above must be created with the-boot-load-seg 0xHHHH option where HHHH is greater than orequal to 1000(hex). If HHHH < 1000(hex), QEMU will hang. Thisis a bug in QEMU. The grldr.iso can be created with or without-boot-load-seg 0xHHHH option.

The menu.lst file should be placed in the root dir of the CD.

Update 6: The Chinese special build is in the "chinese" subdirectory.(patched by Gandalf, 2005-06-27)

The Chinese special build also has scdrom builtin.(update: scdrom has been dropped since 2006-07-20)

Update 7: Added memory drive (md). Like (nd) for network drive and (cd)for CD-ROM drive, a new drive (md) is implemented for accessingthe whole memory as a disk drive. (md) only works for systemswith BIOS int15/EAX=E820h support.

The cat command now has a few new options: --hex for hexdump,and --locate=STRING for string search in file.

Typical examples:

cat --hex (hd0)+1

It will display the MBR sector in hex form.

cat --hex (md)+2

It will display 1KB of your memory(in fact, it is the real-modeIDT table), also in hexdump form.

cat --hex (md)0x800+1

It will display 1 sector of your extended memory.

cat --hex (hd0,0)+1

It will display the first sector of partition (hd0,0). Usuallythis sector contains the boot record of an operating system.

Update 8: Added ram drive (rd). The (md) device accesses the memorystarting at physical address 0. But (rd) accesses memorystarting at any base address. The base and length of the ramdrive can be specified through the map command. "help map" fordetails. You can even specify the BIOS drive number used forthe (rd) drive, e.g., map --ram-drive=0xf0. The default drivenumber for (rd) is 0x7F which is a floppy. If (rd) is a harddrive image, you should change the drive number to a valuegreater than or equal to 0x80(but should avoid using 0xffff,because 0xffff is for the (md) device).

The notation (rd)+1 always represents the file which containsall the bytes stored in (rd).

Update 9: Directly boot NTLDR of WinNT/2K/XP and IO.SYS of Win9x/ME andKERNEL.SYS of FreeDOS. Examples:

chainloader --edx=0xPPYY (hd0,0)/ntldrboot

chainloader --edx=0xYY (hd0,0)/io.sysboot

chainloader --ebx=0xYY (hd0,0)/kernel.sysboot

Hex YY specifies the boot drive number, and hex PP specifiesthe boot partition number of NTLDR. If the boot drive isfloppy, PP should be the hex value ff, i.e., decimal 255.

For KERNEL.SYS of FreeDOS, the --edx won't work,use --ebx please.

The option --edx ( --ebx ) can be omitted if the file is inits normal place. But in some cases, those options are needed.

If, e.g., the ntldr file is in an ext2 partition called(hd2,8) while you want it to think of the Windows partition(hd0,7) as the boot partition, then --edx is required:

chainloader --edx=0x0780 (hd2,8)/ntldr

For DOS kernels(i.e., IO.SYS and KERNEL.SYS), the bootpartition number is meaningless, so you only need to specifythe correct boot drive number YY(but specifying the boot

partition number is harmless).

The above PPYY can also be specified by using a root orrootnoverify command after the chainloader command. Examples:

chainloader (hd2,6)/kernel.sysrootnoverify (hd0) <-------- YY=80boot

chainloader (hd0,0)/ntldrrootnoverify (hd0,5) <-------- YY=80, PP=05boot

Tip: CMLDR (the ComMand LoaDeR, which is used to load theWindows Fault Recovery Console) can be chainloaded as wellas NTLDR.

Bean has successfully decompressed and booted IO.SYS of WinME.Thanks for the great job!

Update 10: isolinux.bin (version 3.73) can be chainloaded as with build2009-02-09.

chainloader (cd)/isolinux.bin

isolinux.bin must reside in a real or virtual cdrom.

Update 11: stage2 of Grub Legacy can be chainloaded in this way:

chainloader --force --load-segment=0 --load-offset=0x8000 --boot-cs=0 --boot-ip=0x8200 (...)/.../stage2

--------------------------------------------------------

There is no full documentation in English at present. Here are someexamples showing the usage of disk emulation commands:

1. Emulates HD partition C: as floppy drive A: and boot win98 from C:

map --read-only (hd0,0)+1 (fd0)chainloader (hd0,0)+1rootnoverify (hd0)boot

In the above example, (hd0,0) is drive C: with win98 on it. After win98boot complete, you will find that A: contains all files of C:, and ifyou delete files in A:, the files in C: will also disappear.

At the map command line, the notation (hdm,n)+1 is interpreted torepresent the whole partition (hdm,n), not just the first sector of thepartition.

2. Emulates HD partition C: as floppy drive A: and boot win98 from A:

map --read-only (hd0,0)+1 (fd0)map --hookchainloader (fd0)+1rootnoverify (fd0)map --floppies=1boot

After the "map --hook" command, the emulation takes effect instantlyeven in the GRUB command line.

Note that the (fd0) in "chainloader (fd0)+1" is the emulated virtualfloppy A:, not the real floppy diskette(because map is hooked now).

3. Emulates an image file as floppy drive A: and boot win98 from C:

map --read-only (hd0,0)/floppy.img (fd0)chainloader (hd0,0)+1rootnoverify (hd0)map --floppies=1map --harddrives=1boot

4. Emulates an HD partition as the first hard disk and boot DOS from it:

map --read-only (hd2,6)+1 (hd0)map --hookchainloader (hd0,0)+1rootnoverify (hd0)map --harddrives=1boot

In this example, (hd2,6)+1 represents an extended logical DOS partitionof the third BIOS hard disk (hd2).

If a DOS partition is used to emulate a hard disk, GRUB for DOS willfirst try to locate the partition table, usually 63 sectors ahead ofthe DOS partition. GRUB for DOS will refuse the emulation if thepartition table is not there.

5. Emulates an image file as the first hard disk and boot DOS from it:

map --read-only (hd0,0)/harddisk.img (hd0)chainloader --load-length=512 (hd0,0)/harddisk.imgrootnoverify (hd0)map --harddrives=1boot

If an image file is used to emulate a hard disk, the image file mustcontain an MBR. In other word, the first sector of HARDDISK.IMG mustcontain the partition table of the emulated virtual hard disk.

Note: Counters for floppies and harddrives in the BIOS Data Area remainunchanged during the mapping. You should manually set them to propervalues with `map --floppies=' and/or `map --harddrives=', especially,e.g., when there is no real floppy drive attached to the mother board.If not doing so, DOS might fail to start.

`map --status' can report the values. Note also that `map --floppies='and `map --harddrives=' can be used independently without theappearance of mappings.

0.4.2 has introduced a new variable, memdisk_raw, to simulate thememdisk-like raw mode. If the BIOS has no int15/87h, or if it hasbuggy int15/87h support, you should set this variable before anymemdrives are used. Here is an example:

map --memdisk-raw=1map --mem (hd0,0)/floppy.img (fd0)map --hookchainloader (fd0)+1rootnoverify (fd0)boot

If you encountered a memdrive failure without usingmap --memdisk-raw=1, you should have a try with `map --memdisk-raw=1'.

If you `map --memdisk-raw=0' later, you should afterwards do a`map --unhook'(and followed by a `map --hook' if needed).

Update: memdisk_raw now defaults to 1. You should `map --memdisk-raw=0'if you want to use int15/87h to access memdrives.

--------------------------------------------------------

Floppies/harddisks of any size can be emulated with GRUB for DOS 0.2.0.

Image file must be contiguous, or else GRUB for DOS will refuse it.

The `blocklist' command can list fragments or pieces of a file.

Type "help map" at the GRUB prompt to get a brief description of thecommand.

The form

map ... (fd?)

is a floppy emulation, and the form

map ... (hd?)

is a hard disk emulation.

When a HARD DISK emulation is used, better not start Windows forsecurity reasons. Windows may even destroy all data and all informationon all your real hard disks!!!!!!!!

Update for --mem: when --mem is used, it seems rather safe even afterentering Windows. Win98 can operate the memdrive normally.

Windows NT/2000/XP does not recognize the emulated drives no matterwhether the --mem option is present.

********************************************************************************* Explanation of the grldr-bootable floppies or harddisk partitions *********************************************************************************

1. Ext2 Boot Sector/Boot Record Layout (for loading grldr)------------------------------------------------------------------------------An EXT2/EXT3 volume can be GRUB-bootable. Copy grldr and an optional menu.lstto the root dir of the EXT2/EXT3 volume, and build the boot sector based on thefifth sector of grldr(some fields need to be changed as detailed in thefollowing table). And then the EXT2/EXT3 volume is GRUB-bootable.

Update: bootlace.com is a DOS/Linux utility that can install the GRLDR bootrecord onto the first sector of an EXT2/EXT3 volume.

Offset Length Description====== ====== ==============================================================00h 2 Machine code for short jump over the data.

02h 1 LBA indicator. Valid values are 0x02 for CHS mode, or 0x42 forLBA mode.

If the BIOS int13 supports LBA, this byte can be safely set to0x42.

Some USB BIOSes might have bugs when using CHS mode, so theformat program should set this byte to 0x42. It seems that(generally) all USB BIOSes have LBA support.

If the format program does not know whether the BIOS has LBAsupport, it may operate this way:

if (partition_start + total_sectors_in_partition) exceeds theCHS addressing ability(especially when it is greater than1024*256*63), the caller should set this byte to 0x42,otherwise, set to 0x02.

Note that Windows98 uses the value 0x0e as the LBA indicator.

Update: this byte of LBA indicator is ignored. The bootrecord can probe the LBA support of BIOS.

03h 10 OEM name string (of OS which formatted the disk).Update: this field is now used for error message of "I/O error"

0Dh 1 Sectors per block. Valid values are 2, 4, 8, 16 and 32.

0Eh 2 Bytes per block. Valid values are 0x400, 0x800, 0x1000, 0x2000and 0x4000.

10h 4 Pointers in pointers-per-block blocks, that is, number ofblocks covered by a double-indirect block.

Valid values are 0x10000, 0x40000, 0x100000, 0x400000 and0x1000000.

14h 4 Pointers per block, that is, number of blocks covered by anindirect block.

Valid values are 0x100, 0x200, 0x400, 0x800, 0x1000.

18h 2 Sectors per track.

1Ah 2 Number of heads/sides.

1Ch 4 Number of hidden sectors (those preceding the boot sector).

Also referred to as the starting sector of the partition.

For floppies, it should be 0.

20h 4 Total number of sectors in the filesystem(or in the partition).

24h 1 BIOS drive number of the boot device.

Actually this byte is ignored for read. The boot code willwrite DL onto this byte. The BIOS or the caller should setdrive number in DL.

We assume all BIOSes pass correct drive number in DL.Buggy BIOSes are not supported!!

25h 1 Partition number of this partition on the boot drive.

0, 1, 2, 3 are primary partitions.4, 5, 6, ... are logical partitions in the extended partition.

0xff is for whole drive. So for floppies, it should be 0xff.

26h 2 inode size in bytes. (Notice! We use the formerly reservedword here for inode size!)

28h 4 Number of inodes per group.

Normally a 1.44M floppy has only one group, and the totalnumber of inodes is 184. So the value should be 184 orgreater.

2Ch 4 The block number for group descriptors.

Valid values are 2 for 1024-byte blocks, and 1 otherwise.

The value here is equal to (s_first_data_block + 1).

30h 1 code for "cld"(0xFC).

31h 2 code for "xor ax,ax"(0x31, 0xC0).

33h 1 code for "nop"(0x90) or "cwd"(0x99)

34h 458 The rest of the machine code.

1FEh 2 Boot Signature AA55h.

2. FAT12/FAT16 Boot Sector/Boot Record Layout (for loading grldr)------------------------------------------------------------------------------A FAT12/16 volume can be GRUB-bootable. Copy grldr and an optional menu.lst tothe root dir of the FAT12/16 volume, and build the boot sector based on thefourth sector of grldr(some fields need to be changed as detailed in thefollowing table). And then the FAT12/16 volume is GRUB-bootable.

Update: bootlace.com is a DOS/Linux utility that can install the GRLDR bootrecord onto the boot sector of an FAT12/16 volume.


02h 1 LBA indicator. Valid values are 0x90 for CHS mode, or 0x0e forLBA mode.

If the BIOS int13 supports LBA, this byte can be safely set to0x0e.

Some USB BIOSes might have bugs when using CHS mode, so theformat program should set this byte to 0x0e. It seems that(generally) all USB BIOSes have LBA support.


if (partition_start + total_sectors_in_partition) exceeds theCHS addressing ability(especially when it is greater than1024*256*63), the caller should set this byte to 0x0e,otherwise, set to 0x90.


Update(2006-07-31): Though GRLDR won't use this LBA-indicatorbyte, Windows 98 uses it. Usually this byte should be 0x90 forCHS mode(especially for floppies). If this byte is not setproperly, Windows 98 will not recognize the floppy orpartition. This problem was reported by neiljoy. Many thanks!

03h 8 OEM name string (of OS which formatted the disk).

0Bh 2 Bytes per sector. Must be 512.

0Dh 1 Sectors per cluster. Valid values are 1, 2, 4, 8, 16, 32, 64and 128. But a cluster size larger than 32K should not occur.

0Eh 2 Reserved sectors(number of sectors before the first FAT,including the boot sector), usually 1.

10h 1 Number of FATs(nearly always 2).

11h 2 Maximum number of root directory entries.

13h 2 Total number of sectors (for small disks only, if the disk istoo big this is set to 0 and offset 20h is used instead).

15h 1 Media descriptor byte, pretty meaningless now (see below).

16h 2 Sectors per FAT.


1Ah 2 Total number of heads/sides.




20h 4 Total number of sectors for large disks.




25h 1 Partition number of this filesystem in the boot drive.

This byte is ignored for read. The boot code will writepartition number onto this byte. See offset 41h below.

26h 1 Signature (must be 28h or 29h to be recognised by NT).

27h 4 Volume serial number.

2Bh 11 Volume label.

36h 8 File system ID. "FAT12 ", "FAT16 " or "FAT ".

3Eh 1 code for "cli".

3Fh 1 code for "cld".

40h 1 code for "mov dh, imm8".




42h 442 The rest of the machine code.

1FCh 4 Boot Signature AA550000h. (Win9x uses 4 bytes as magic value)

3. FAT32 Boot Sector/Boot Record Layout (for loading grldr)------------------------------------------------------------------------------A FAT32 volume can be GRUB-bootable. Copy grldr and an optional menu.lst tothe root dir of the FAT32 volume, and build the boot sector based on thethird sector of grldr(some fields need to be changed as detailed in thefollowing table). And then the FAT32 volume is GRUB-bootable.

Update: bootlace.com is a DOS/Linux utility that can install the GRLDR bootrecord onto the boot sector of an FAT32 volume.




Some USB BIOSes might have bugs when using CHS mode, so theformat program should set this byte to 0x0e. It seems that

(generally) all USB BIOSes have LBA support.








0Eh 2 Reserved sectors(number of sectors before the first FAT,including the boot sector), usually 1.

10h 1 Number of FATs(nearly always 2).

11h 2 (Maximum number of root directory entries)Must be 0.

13h 2 (Total number of sectors for small disks only)Must be 0.


16h 2 (Sectors per FAT)Must be 0.






20h 4 Total number of sectors for large disks.

24h 4 FAT32 sectors per FAT.

28h 2 If bit 7 is clear then all FATs are updated, otherwise bits0-3 give the current active FAT, all other bits are reserved.

2Ah 2 High byte is major revision number, low byte is minor revisionnumber, currently both are 0.

2Ch 4 Root directory starting cluster.

30h 2 File system information sector.

32h 2 If non-zero this gives the sector which holds a copy of theboot record, usually 6.

34h 12 Reserved, set to 0.


80h is first HDD, 00h is first FDD.



41h 1 Partition number of this filesystem in the boot drive.

This byte is ignored for read. The boot code will writepartition number onto this byte. See offset 5Dh below.

42h 1 Signature (must be 28h or 29h to be recognised by NT).


47h 11 Volume label.

52h 8 File system ID. "FAT32 ".

5Ah 1 opcode for "cli".

5Bh 1 opcode for "cld".

5Ch 1 opcode for "mov dh, imm8".

5Dh 1 Partition number of this partition on the boot drive.



5Eh 414 The rest of the machine code.


4. NTFS Boot Sector/Boot Record Layout (for loading grldr)------------------------------------------------------------------------------An NTFS volume can be GRUB-bootable. Copy grldr and an optional menu.lst tothe root dir of the NTFS volume, and build the boot sector based on the6th-9th sectors of grldr(some fields need to be changed as detailed in thefollowing table). And then the NTFS volume is GRUB-bootable.

Update: bootlace.com is a DOS/Linux utility that can install the GRLDR bootrecord onto the leading 4 sectors of an NTFS volume.




Some USB BIOSes might have bugs when using CHS mode, so theformat program should set this byte to 0x0e. It seems that(generally) all USB BIOSes have LBA support.








0Eh 2 (Reserved sectors)Unused.

10h 1 (Number of FATs)Must be 0.

11h 2 (Maximum number of root directory entries)Must be 0.

13h 2 (Total number of sectors for small disks only)Must be 0.


16h 2 (Sectors per FAT)Must be 0.






20h 4 (Total number of sectors for large disks)Must be 0.

24h 4 (FAT32 sectors per FAT) - Usually 80 00 80 00, A value of80 00 00 00 has been seen on a USB thumb drive which isformatted with NTFS under Windows XP. Note this is removablemedia and is not partitioned, the drive as a whole is NTFSformatted.

28h 8 Number of sectors in the volume.

30h 8 LCN of VCN 0 of the $MFT.

38h 8 LCN of VCN 0 of the $MFTMirr.

40h 4 Clusters per MFT Record.

44h 4 Clusters per Index Record.


50h 4 Checksum, usually 0.

54h 1 opcode for "cli".

55h 1 opcode for "cld".

56h 1 opcode for "mov dh, imm8".




58h 420 The rest of the machine code in the first sector.


200h 1536 The rest of the machine code in the last 3 sectors.

------------------------------------------------------------------------------

Appendix A: File System Information Sector of FAT32(not used by grldr)

Offset Length Description====== ====== ==============================================================0h 4 Leading Signature 41615252h.

4h 480 Reserved, set to 0.

1E4h 4 FSI structure signature 61417272h.

1E8h 4 Contains the last known count of free clusters, if this isequal to FFFFFFFFh, then the count is unknown.

1ECh 4 Cluster number at which you should begin a search for a freecluster, if this is equal to FFFFFFFFh then the field has notbeen set.

1F0h 12 Reserved, set to 0.

1FCh 4 Trailing Signature AA550000h.

------------------------------------------------------------------------------

Appendix B: Media Descriptor Byte(not used by grldr)

The Media descriptor byte is meaningless because of the duplications, F0h forexample.

Byte Type of disk Sectors Heads Tracks Capacity---- ------------ ------- ----- ------ --------FFh 5 1/4" 8 2 40 320KBFEh 5 1/4" 8 1 40 160KBFDh 5 1/4" 9 2 40 360KBFCh 5 1/4" 9 1 40 180KBFBh both 9 2 80 640KBFAh both 9 1 80 320KBF9h 5 1/4" 15 2 80 1200KBF9h 3 1/2" 9 2 80 720KBF0h 3 1/2" 18 2 80 1440KBF0h 3 1/2" 36 2 80 2880KBF8h hard disk NA NA NA NA

********************************************************************************* grldr.mbr - How to write it to Master Boot Track of the hard disk *********************************************************************************

grldr.mbr contains code that can be used as Master Boot Record. The code isresponsible for searching all partitions for grldr and when found, loading it.Currently supported partition types are: FAT12/FAT16/FAT32, NTFS, EXT2/EXT3.Logical partitions in the extended partition are supported, provided that theextended partition type is Microsoft-compatible. In fact, the Linux extendedpartition type(0x85) is not fully tested for the search mechanism.

How to write GRLDR.MBR to the Master Boot Track of a hard disk?

First, read the Windows disk signature and partition information bytes(72 bytes in total, from offset 0x01b8 to 0x01ff of the MBR sector), and putthem on the same range from offset 0x01b8 to 0x01ff of the beginning sector ofGRLDR.MBR.

Optionally, if the MBR in the hard disk is a single sector MBR created byMicrosoft FDISK, it may be copied onto the second sector of GRLDR.MBR.

The second sector of GRLDR.MBR is called "previous MBR". When GRLDR not found,"previous MBR" will be started.

No other steps needed, after all necessary changes stated above have been made,now simply write GRLDR.MBR on to the Master Boot Track. That's all.

Note: The Master Boot Track means the first track of the hard drive.

Note: The bootstrap code of GRLDR.MBR only finds GRLDR file in the root dir ofa partition. You'd better place menu.lst file accompanying with GRLDR(i.e., inthe same root dir of the same partition as GRLDR).

The filename "grldr" in an ext2 partition must be in lower case letters, andthe file type of grldr must be plain regular. Other types, e.g., a symbolic

link, won't work.

Update: bootlace.com is a DOS/Linux utility for installing grldr.mbr to MBR.The whole grldr.mbr is embedded in the body of the bootlace.com utility, sobootlace.com can be used independently. See below.

********************************************************************************* grldr.mbr - Details about the control bytes *********************************************************************************

Six bytes can be used to control the boot process of GRLDR.MBR.

Offset Length Description====== ====== ==============================================================02h 1 bit0=1: disable the search for GRLDR on floppy

bit0=0: enable the search for GRLDR on floppy

bit1=1: disable the boot of PREVIOUS MBR with invalidpartition table(usually an OS boot sector)

bit1=0: enable the boot of PREVIOUS MBR with invalidpartition table(usually an OS boot sector)

bit2=1: disable the feature of unconditional entrance tothe command-line(See below `--duce')

bit2=0: enable the feature of unconditional entrance tothe command-line(See below `--duce')

bit3=1: disable geometry tune(See below `--chs-no-tune')bit3=0: enable geometry tune(See below `--chs-no-tune')

bit4 - bit6: reserved

bit7=1: try to boot PREVIOUS MBR after the search for GRLDRbit7=0: try to boot PREVIOUS MBR before the search for GRLDR

03h 1 timeout in seconds to wait for a key press. 0xff stands forwaiting all the time(endless).

04h 2 hot-key code. high byte is scan code, low byte is ASCII code.the default value is 0x3920, which stands for the space bar.if this key is pressed, GRUB will be started prior to the bootof previous MBR. See "int 16 keyboard scan codes" below.

06h 1 preferred boot drive number, 0xff for no-drive07h 1 preferred partition number, 0xff for whole drive

if the preferred boot drive number is 0xff, the order of thesearch for GRLDR will be:

(hd0,0), (hd0,1), ..., (hd0,L),(L=max partition number) (hd1,0), (hd1,1), ..., (hd1,M),(M=max partition number)... ... ... ... ... ... ... ... (hdX,0), (hdX,1), ..., (hdX,N),(N=max partition number)

(X=max harddrive number)(fd0)

otherwise, if the preferred boot drive number is Y(not equal to0xff) and the preferred partition number is K, then the order ofthe search for GRLDR will be:

(Y) if K=0xff; or (Y,K) otherwise(hd0,0), (hd0,1), ..., (hd0,L),(L=max partition number) (hd1,0), (hd1,1), ..., (hd1,M),(M=max partition number)... ... ... ... ... ... ... ... (hdX,0), (hdX,1), ..., (hdX,N),(N=max partition number)

(X=max harddrive number)(fd0)

Note: if Y < 0x80, then (Y) is floppy, else (Y) is harddrive, and (Y,K) is partition number K on harddrive (Y).

********************************************************************************* bootlace.com - Install GRLDR.MBR bootstrap code to MBR *********************************************************************************

BOOTLACE.COM installs GRLDR.MBR boot record to the MBR of a harddrive or of aharddrive image file, or to the boot sector of a floppy or a floppy image.

Usage:

bootlace.com [OPTIONS] DEVICE_OR_FILE

OPTIONS:

--read-only do everything except the actual write to thespecified DEVICE_OR_FILE.

--restore-mbr restore the previous mbr.

--mbr-no-bpb do not copy BPB in the boot sector of theleading FAT partition to MBR.

--no-backup-mbr do not copy the old MBR to the second sector ofDEVICE_OR_FILE.

--force-backup-mbr force the copy of old MBR to the second sectorof DEVICE_OR_FILE.

--mbr-enable-floppy enable the search for GRLDR on floppy.

--mbr-disable-floppy disable the search for GRLDR on floppy.

--mbr-enable-osbr enable the boot of PREVIOUS MBR with invalidpartition table(usually an OS boot sector).

--mbr-disable-osbr disable the boot of PREVIOUS MBR with invalidpartition table(usually an OS boot sector).

--duce disable the feature of unconditional entrance to the command-line.

Normally one can unconditionally get thecommand-line console by a keypress of `C',bypassing all config-files(including thepreset-menu). This is a security hole. So weneed this option to disable the feature.

DUCE is for Disable Unconditional Command-lineEntrance.

--chs-no-tune disable the feature of geometry tune.

--boot-prevmbr-first try to boot PREVIOUS MBR before the search forGRLDR.

--boot-prevmbr-last try to boot PREVIOUS MBR after the search forGRLDR.

--preferred-drive=D preferred boot drive number, 0 <= D < 255.

--preferred-partition=P preferred partition number, 0 <= P < 255.

--serial-number=SN setup a new serial number for the hard drive.SN must be non-zero.

--time-out=T wait T seconds before booting PREVIOUS MBR. ifT is 0xff, wait forever. The default is 5.

--hot-key=K if the desired key K is pressed, start GRUBbefore booting PREVIOUS MBR. K is a wordvalue, just as the value in AX registerreturned from int16/AH=1. The high byte is thescan code and the low byte is ASCII code. Thedefault is 0x3920 for space bar. See "int 16keyboard scan codes" below.

--floppy if DEVICE_OR_FILE is floppy, use this option.

--floppy=N if DEVICE_OR_FILE is a partition on a harddrive, use this option. N is used to specifythe partition number: 0,1,2 and 3 for theprimary partitions, and 4,5,6,... for thelogical partitions.

--sectors-per-track=S specifies sectors per track for --floppy.1 <= S <= 63, default is 63.

--heads=H specifies number of heads for --floppy.1 <= H <= 256, default is 255.

--start-sector=B specifies hidden sectors for --floppy=N.

--total-sectors=C specifies total sectors for --floppy.default is 0.

--lba use lba mode for --floppy. If the floppy BIOShas LBA support, you can specify --lba here.It is assumed that all floppy BIOSes have CHSsupport. So you would rather specify --chs.If neither --chs nor --lba is specified, thenthe LBA indicator(i.e., the third byte of theboot sector) will not be touched.

--chs use chs mode for --floppy. You should specify--chs if the floppy BIOS does not support LBA.We assume all floppy BIOSes have CHS support.So it is likely you want to specify --chs.If neither --chs nor --lba is specified, thenthe LBA indicator(i.e., the third byte of the

boot sector) will not be touched.

--fat12 FAT12 is allowed to be installed for --floppy.



--vfat FAT12/16/32 are allowed to be installed for--floppy.

--ntfs NTFS is allowed to be installed for --floppy.

--ext2 EXT2 is allowed to be installed for --floppy.

--install-partition=I Install the boot record onto the boot area ofpartition number I of the specified hard driveor harddrive image DEVICE_OR_FILE.

DEVICE_OR_FILE: Filename of the device or the image file. For DOS, a BIOS drivenumber(hex 0xHH or decimal DDD) can be used to access the drive. BIOS drivenumber 0 is for the first floppy, 1 is for the second floppy; 0x80 is for thefirst hard drive, 0x81 is for the second hard drive, etc.

Note: BOOTLACE.COM writes only the boot code to MBR. The boot code needs toload GRLDR as the second(and last) stage of the GRUB boot process. ThereforeGRLDR should be copied to the root directory of one of the supportedpartitions, either before or after a successful execution of BOOTLACE.COM.Currently only partitions with filesystem type of FAT12, FAT16, FAT32, NTFS,EXT2 or EXT3 are supported.

Note 2: If DEVICE_OR_FILE is a harddisk device or a harddisk image file, itmust contain a valid partition table, otherwise, BOOTLACE.COM will fail. IfDEVICE_OR_FILE is a floppy device or a floppy image file, then it must containa supported filesystem(i.e., either of FAT12/FAT16/FAT32/NTFS/EXT2/EXT3).

Note 3: If DEVICE_OR_FILE is a floppy device or a floppy image file, and itwas formated EXT2/EXT3, then you should specify --sectors-per-track and--heads explicitly.

Important!! If you install GRLDR Boot Record to a floppy or a partition, thefloppy or partition will boot solely grldr, and your originalIO.SYS(DOS/Win9x/Me) and NTLDR(WinNT/2K/XP) will become unbootable. This isbecause the original boot record of the floppy or partition was overwritten.There is no such problem when installing GRLDR Boot Record onto the MBR.Update: Some NTLDR/IO.SYS/KERNEL.SYS files can be directly chainloaded in thelatest GRUB4DOS.

Tip: If the filename begins in a dash(-) or a digit, you may prefix a dirname(./) or (.\) to it.

Examples:

Installing GRLDR boot code to MBR under Linux:

bootlace.com /dev/hda

Installing GRLDR boot code to MBR under DOS:

bootlace.com 0x80

Installing GRLDR boot code to a harddisk image under DOS or Linux:

bootlace.com hd.img

Installing GRLDR boot code to floppy under Linux:

bootlace.com --floppy --chs /dev/fd0

Installing GRLDR boot code to floppy under DOS:

bootlace.com --floppy --chs 0x00

Installing GRLDR boot code to a floppy image under DOS or Linux:

bootlace.com --floppy --chs floppy.img

BOOTLACE.COM cannot function well under Windows NT/2000/XP/2003. It is expected(and designed) to run under DOS/Win9x and Linux. Update: For image FILES,bootlace.com function well under Windows NT/2000/XP/2003. For devices,bootlace.com will not work under Windows NT/2000/XP/2003 because bootlace.comis a DOS utility and Windows NT/2000/XP/2003 does not allow bootlace.com toaccess devices.

********************************************************************************* kexec-tools should be patched for the 1.101 release *********************************************************************************

The file kexec-tools-1.101-patch is a patch to the kexec-tools-1.101 release.Kexec might fail to load grub.exe without this patch.

The home page of kexec-tools is:

http://www.xmission.com/~ebiederm/files/kexec/

Note: The Linux kernel should be KEXEC enabled before kexec can be run.

!! Important Update !!

The patch `kexec-tools-1.101-patch' is not needed now and has been deleted.Even worse, it fails in `kexec -l grub.exe --initrd=imgfile'. So pleasedo not use it any more.

********************************************************************************* Direct transition to DOS/Win9x from within Linux *********************************************************************************

By using kexec, we can easily boot into DOS/Win9x from a running Linux system.

If WIN98.IMG is a bootable hard-disk image, do as follows:

kexec -l grub.exe --initrd=WIN98.IMG --command-line="--config-file=map (rd) (hd0); map --hook; chainloader (hd0)+1; rootnoverify (hd0)"

kexec -e

If DOS.IMG is a bootable floppy image, do this way:

kexec -l grub.exe --initrd=DOS.IMG --command-line="--config-file=map (rd) (fd0);

map --hook; chainloader (fd0)+1; rootnoverify (fd0)"

kexec -e

Note that in this manner, we can boot DOS/Win9x without using a real DOS/Win9xdisk. We need no FAT partition but an image file.

We have noticed that Linux itself can act as a big boot manager by using kexecand grub.exe. This may be convenient to developers who write installation orbootstrap or initialization programs.

Certainly, grub.exe and the bootable disk image can also be loaded by a runningGRUB or LILO or syslinux. Examples:

1. Loaded by GRUB:

kernel (hd0,0)/grub.exe --config-file="map (rd) (fd0); map --hook; chainloader (fd0)+1; rootnoverify (fd0)"

initrd (hd0,0)/DOS.IMGboot

2. Loaded by LILO:

image=/boot/grub.exelabel=grub.exeinitrd=/boot/DOS.IMGappend="--config-file=map (rd) (fd0); map --hook; chainloader (f

d0)+1; rootnoverify (fd0)"

3. Loaded by SYSLINUX:

label grub.exekernel grub.exeappend initrd=DOS.IMG --config-file="map (rd) (fd0); map --hook;

chainloader (fd0)+1; rootnoverify (fd0)"

Note: If the above `map (rd) (...)' failed, you may use `map (rd)+1 (...)'instead and try again.

********************************************************************************* Keyboard BIOS Scan Code/ASCII code tables *********************************************************************************

Keyboard bios scan code and ascii character code tables can be obtained fromthe web by, for example, googling for "3920 372A 4A2D 4E2B 352F". Here are 2main results:

1. From "http://heim.ifi.uio.no/~stanisls/helppc/scan_codes.html":

INT 16 - Keyboard Scan Codes

Key Normal Shifted w/Ctrl w/Alt

A 1E61 1E41 1E01 1E00B 3062 3042 3002 3000C 2E63 2E43 2E03 2E00D 2064 2044 2004 2000E 1265 1245 1205 1200F 2166 2146 2106 2100G 2267 2247 2207 2200

H 2368 2348 2308 2300I 1769 1749 1709 1700J 246A 244A 240A 2400K 256B 254B 250B 2500L 266C 264C 260C 2600M 326D 324D 320D 3200N 316E 314E 310E 3100O 186F 184F 180F 1800P 1970 1950 1910 1900Q 1071 1051 1011 1000R 1372 1352 1312 1300S 1F73 1F53 1F13 1F00T 1474 1454 1414 1400U 1675 1655 1615 1600V 2F76 2F56 2F16 2F00W 1177 1157 1117 1100X 2D78 2D58 2D18 2D00Y 1579 1559 1519 1500Z 2C7A 2C5A 2C1A 2C00


1 0231 0221 78002 0332 0340 0300 79003 0433 0423 7A004 0534 0524 7B005 0635 0625 7C006 0736 075E 071E 7D007 0837 0826 7E008 0938 092A 7F009 0A39 0A28 80000 0B30 0B29 8100


- 0C2D 0C5F 0C1F 8200= 0D3D 0D2B 8300[ 1A5B 1A7B 1A1B 1A00] 1B5D 1B7D 1B1D 1B00; 273B 273A 2700' 2827 2822` 2960 297E\ 2B5C 2B7C 2B1C 2600 (same as Alt L), 332C 333C. 342E 343E/ 352F 353F


F1 3B00 5400 5E00 6800F2 3C00 5500 5F00 6900F3 3D00 5600 6000 6A00F4 3E00 5700 6100 6B00F5 3F00 5800 6200 6C00F6 4000 5900 6300 6D00F7 4100 5A00 6400 6E00F8 4200 5B00 6500 6F00F9 4300 5C00 6600 7000F10 4400 5D00 6700 7100F11 8500 8700 8900 8B00

F12 8600 8800 8A00 8C00


BackSpace 0E08 0E08 0E7F 0E00Del 5300 532E 9300 A300Down Arrow 5000 5032 9100 A000End 4F00 4F31 7500 9F00Enter 1C0D 1C0D 1C0A A600Esc 011B 011B 011B 0100Home 4700 4737 7700 9700Ins 5200 5230 9200 A200Keypad 5 4C35 8F00Keypad * 372A 9600 3700Keypad - 4A2D 4A2D 8E00 4A00Keypad + 4E2B 4E2B 4E00Keypad / 352F 352F 9500 A400Left Arrow 4B00 4B34 7300 9B00PgDn 5100 5133 7600 A100PgUp 4900 4939 8400 9900PrtSc 7200Right Arrow 4D00 4D36 7400 9D00SpaceBar 3920 3920 3920 3920Tab 0F09 0F00 9400 A500Up Arrow 4800 4838 8D00 9800

- Some key combinations are not available on all systems. The PS/2 includes many that aren't available on the PC, XT and AT.- To retrieve the character from a scan code logical AND the word with 0x00FF.- see INT 16 MAKE CODES

2. From "http://www.hoppie.nl/ivan/keycodes.txt":

Keystroke Keypress code-------------------------------------------------- Esc 011B 1 0231 2 0332 3 0433 4 0534 5 0635 6 0736 7 0837 8 0938 9 0A39 0 0B30 - 0C2D = 0D3D Backspace 0E08 Tab 0F09 q 1071 w 1177 e 1265 r 1372

t 1474 y 1579 u 1675 i 1769 o 186F p 1970 [ 1A5B ] 1B5D Enter 1C0D Ctrl ** a 1E61 s 1F73 d 2064 f 2166 g 2267 h 2368 j 246A k 256B l 266C ; 273B ' 2827 ` 2960 Shift ** \ 2B5C z 2C7A x 2D78 c 2E63 v 2F76 b 3062 n 316E m 326D , 332C . 342E / 352F Gray * 372A Alt ** Space 3920 Caps Lock ** F1 3B00 F2 3C00 F3 3D00 F4 3E00 F5 3F00 F6 4000 F7 4100 F8 4200 F9 4300 F10 4400 F11 8500 F12 8600 Num Lock ** Scroll Lock ** White Home 4700 White Up Arrow 4800 White PgUp 4900 Gray - 4A2D White Left Arrow 4B00 Center Key 4C00 White Right Arrow 4D00 Gray + 4E2B

White End 4F00 White Down Arrow 5000 White PgDn 5100 White Ins 5200 White Del 5300 SysReq ** Key 45 [1] 565C Enter (number keypad) 1C0D Gray / 352F PrtSc ** Pause ** Gray Home 4700 Gray Up Arrow 4800 Gray Page Up 4900 Gray Left Arrow 4B00 Gray Right Arrow 4D00 Gray End 4F00 Gray Down Arrow 5000 Gray Page Down 5100 Gray Insert 5200 Gray Delete 5300

Shift Esc 011B ! 0221 @ 0340 # 0423 $ 0524 % 0625 ^ 075E & 0826 * (white) 092A ( 0A28 ) 0B29 _ 0C5F + (white) 0D2B Shift Backspace 0E08 Shift Tab (Backtab) 0F00 Q 1051 W 1157 E 1245 R 1352 T 1454 Y 1559 U 1655 I 1749 O 184F P 1950 { 1A7B } 1B7D Shift Enter 1C0D Shift Ctrl ** A 1E41 S 1F53 D 2044 F 2146 G 2247 H 2348 J 244A K 254B L 264C

: 273A " 2822 ~ 297E | 2B7C Z 2C5A X 2D58 C 2E43 V 2F56 B 3042 N 314E M 324D < 333C > 343E ? 353F Shift Gray * 372A Shift Alt ** Shift Space 3920 Shift Caps Lock ** Shift F1 5400 Shift F2 5500 Shift F3 5600 Shift F4 5700 Shift F5 5800 Shift F6 5900 Shift F7 5A00 Shift F8 5B00 Shift F9 5C00 Shift F10 5D00 Shift F11 8700 Shift F12 8800 Shift Num Lock ** Shift Scroll Lock ** Shift 7 (number pad) 4737 Shift 8 (number pad) 4838 Shift 9 (number pad) 4939 Shift Gray - 4A2D Shift 4 (number pad) 4B34 Shift 5 (number pad) 4C35 Shift 6 (number pad) 4D36 Shift Gray + 4E2B Shift 1 (number pad) 4F31 Shift 2 (number pad) 5032 Shift 3 (number pad) 5133 Shift 0 (number pad) 5230 Shift . (number pad) 532E Shift SysReq ** Shift Key 45 [1] 567C Shift Enter (number pad) 1C0D Shift Gray / 352F Shift PrtSc ** Shift Pause ** Shift Gray Home 4700 Shift Gray Up Arrow 4800 Shift Gray Page Up 4900 Shift Gray Left Arrow 4B00 Shift Gray Right Arrow 4D00 Shift Gray End 4F00 Shift Gray Down Arrow 5000 Shift Gray Page Down 5100 Shift Gray Insert 5200

Shift Gray Delete 5300

Ctrl Esc 011B Ctrl 1 -- Ctrl 2 (NUL) 0300 Ctrl 3 -- Ctrl 4 -- Ctrl 5 -- Ctrl 6 (RS) 071E Ctrl 7 -- Ctrl 8 -- Ctrl 9 -- Ctrl 0 -- Ctrl - 0C1F Ctrl = -- Ctrl Backspace (DEL) 0E7F Ctrl Tab 9400 Ctrl q (DC1) 1011 Ctrl w (ETB) 1117 Ctrl e (ENQ) 1205 Ctrl r (DC2) 1312 Ctrl t (DC4) 1414 Ctrl y (EM) 1519 Ctrl u (NAK) 1615 Ctrl i (HT) 1709 Ctrl o (SI) 180F Ctrl p (DEL) 1910 Ctrl [ (ESC) 1A1B Ctrl ] (GS) 1B1D Ctrl Enter (LF) 1C0A Ctrl a (SOH) 1E01 Ctrl s (DC3) 1F13 Ctrl d (EOT) 2004 Ctrl f (ACK) 2106 Ctrl g (BEL) 2207 Ctrl h (Backspace) 2308 Ctrl j (LF) 240A Ctrl k (VT) 250B Ctrl l (FF) 260C Ctrl ; -- Ctrl ' -- Ctrl ` -- Ctrl Shift ** Ctrl \ (FS) 2B1C Ctrl z (SUB) 2C1A Ctrl x (CAN) 2D18 Ctrl c (ETX) 2E03 Ctrl v (SYN) 2F16 Ctrl b (STX) 3002 Ctrl n (SO) 310E Ctrl m (CR) 320D Ctrl , -- Ctrl . -- Ctrl / -- Ctrl Gray * 9600 Ctrl Alt ** Ctrl Space 3920 Ctrl Caps Lock -- Ctrl F1 5E00 Ctrl F2 5F00

Ctrl F3 6000 Ctrl F4 6100 Ctrl F5 6200 Ctrl F6 6300 Ctrl F7 6400 Ctrl F8 6500 Ctrl F9 6600 Ctrl F10 6700 Ctrl F11 8900 Ctrl F12 8A00 Ctrl Num Lock -- Ctrl Scroll Lock -- Ctrl White Home 7700 Ctrl White Up Arrow 8D00 Ctrl White PgUp 8400 Ctrl Gray - 8E00 Ctrl White Left Arrow 7300 Ctrl 5 (number pad) 8F00 Ctrl White Right Arrow 7400 Ctrl Gray + 9000 Ctrl White End 7500 Ctrl White Down Arrow 9100 Ctrl White PgDn 7600 Ctrl White Ins 9200 Ctrl White Del 9300 Ctrl SysReq ** Ctrl Key 45 [1] -- Ctrl Enter (number pad) 1C0A Ctrl / (number pad) 9500 Ctrl PrtSc 7200 Ctrl Break 0000 Ctrl Gray Home 7700 Ctrl Gray Up Arrow 8DE0 Ctrl Gray Page Up 8400 Ctrl Gray Left Arrow 7300 Ctrl Gray Right Arrow 7400 Ctrl Gray End 7500 Ctrl Gray Down Arrow 91E0 Ctrl Gray Page Down 7600 Ctrl Gray Insert 92E0 Ctrl Gray Delete 93E0

Alt Esc 0100 Alt 1 7800 Alt 2 7900 Alt 3 7A00 Alt 4 7B00 Alt 5 7C00 Alt 6 7D00 Alt 7 7E00 Alt 8 7F00 Alt 9 8000 Alt 0 8100 Alt - 8200 Alt = 8300 Alt Backspace 0E00 Alt Tab A500 Alt q 1000 Alt w 1100 Alt e 1200

Alt r 1300 Alt t 1400 Alt y 1500 Alt u 1600 Alt i 1700 Alt o 1800 Alt p 1900 Alt [ 1A00 Alt ] 1B00 Alt Enter 1C00 Alt Ctrl ** Alt a 1E00 Alt s 1F00 Alt d 2000 Alt f 2100 Alt g 2200 Alt h 2300 Alt j 2400 Alt k 2500 Alt l 2600 Alt ; 2700 Alt ' 2800 Alt ` 2900 Alt Shift ** Alt \ 2B00 Alt z 2C00 Alt x 2D00 Alt c 2E00 Alt v 2F00 Alt b 3000 Alt n 3100 Alt m 3200 Alt , 3300 Alt . 3400 Alt / 3500 Alt Gray * 3700 Alt Space 3920 Alt Caps Lock ** Alt F1 6800 Alt F2 6900 Alt F3 6A00 Alt F4 6B00 Alt F5 6C00 Alt F6 6D00 Alt F7 6E00 Alt F8 6F00 Alt F9 7000 Alt F10 7100 Alt F11 8B00 Alt F12 8C00 Alt Num Lock ** Alt Scroll Lock ** Alt Gray - 4A00 Alt Gray + 4E00 Alt 7 (number pad) # Alt 8 (number pad) # Alt 9 (number pad) # Alt 4 (number pad) # Alt 5 (number pad) # Alt 6 (number pad) #

Alt 1 (number pad) # Alt 2 (number pad) # Alt 3 (number pad) # Alt Del -- Alt SysReq ** Alt Key 45 [1] -- Alt Enter (number pad) A600 Alt / (number pad) A400 Alt PrtSc ** Alt Pause ** Alt Gray Home 9700 Alt Gray Up Arrow 9800 Alt Gray Page Up 9900 Alt Gray Left Arrow 9B00 Alt Gray Right Arrow 9D00 Alt Gray End 9F00 Alt Gray Down Arrow A000 Alt Gray Page Down A100 Alt Gray Insert A200 Alt Gray Delete A300

-------------------------------------------------------------------------

Footnotes

[1] In the United States, the 101/102-key keyboard is shipped with 101 keys. Overseas versions have an additional key sandwiched between the left Shift key and the Z key. This additional key is identified by IBM (and in this table) as "Key 45."

[**] Keys and key combinations marked ** are used by the ROM BIOS but do not put values into the keyboard buffer.

[--] Keys and key combinations marked -- are ignored by the ROM BIOS.

3. From "http://heim.ifi.uio.no/~stanisls/helppc/make_codes.html":

INT 9 - Hardware Keyboard Make/Break Codes

Key Make Break Key Make Break

Backspace 0E 8E F1 3B BBCaps Lock 3A BA F2 3C BCEnter 1C 9C F3 3D BDEsc 01 81 F4 3E BELeft Alt 38 B8 F7 41 C1Left Ctrl 1D 9D F5 3F BFLeft Shift 2A AA F6 40 C0Num Lock 45 C5 F8 42 C2Right Shift 36 B6 F9 43 C3Scroll Lock 46 C6 F10 44 C4Space 39 B9 F11 57 D7Sys Req (AT) 54 D4 F12 58 D8Tab 0F 8F

Keypad Keys Make Break

Keypad 0 (Ins) 52 D2 Keypad 1 (End) 4F CF Keypad 2 (Down arrow) 50 D0 Keypad 3 (PgDn) 51 D1 Keypad 4 (Left arrow) 4B CB Keypad 5 4C CC Keypad 6 (Right arrow) 4D CD Keypad 7 (Home) 47 C7 Keypad 8 (Up arrow) 48 C8 Keypad 9 (PgUp) 49 C9 Keypad . (Del) 53 D3 Keypad * (PrtSc) 37 B7 Keypad - 4A CA Keypad + 4E CE


A 1E 9E N 31 B1B 30 B0 O 18 98C 2E AE P 19 99D 20 A0 Q 10 90E 12 92 R 13 93F 21 A1 S 1F 9FG 22 A2 T 14 94H 23 A3 U 16 96I 17 97 V 2F AFJ 24 A4 W 11 91K 25 A5 X 2D ADL 26 A6 Y 15 95M 32 B2 Z 2C AC


1 02 82 - 0C 8C2 03 83 = 0D 8D3 04 84 [ 1A 9A4 05 85 ] 1B 9B5 06 86 ; 27 A76 07 87 ' 28 A87 08 88 ` 29 A98 09 89 \ 2B AB9 0A 8A , 33 B30 0B 8B . 34 B4

/ 35 B5

Enhanced Keyboard Keys (101/102 keys)

Control Keys Make Break

Alt-PrtSc (SysReq) 54 D4Ctrl-PrtSc E0 37 E0 B7Enter E0 1C E0 9CPrtSc E0 2A E0 37 E0 B7 E0 AARight Alt E0 38 E0 B8Right Ctrl E0 1D E0 9DShift-PrtSc E0 37 E0 B7

/ E0 35 E0 B5Pause E1 1D 45 E1 9D C5 (not typematic)Ctrl-Pause (Ctrl-Break) E0 46 E0 C6 (not typematic)

- Keys marked as "not typematic" generate one stream of bytes without corresponding break scan code bytes (actually the break codes are part of the make code).

Normal Mode orShift w/Numlock

Key Make Break |----- Numlock on ------. Make Break

Del E0 53 E0 D3 E0 2A E0 53 E0 D3 E0 AADown arrow E0 50 E0 D0 E0 2A E0 50 E0 D0 E0 AAEnd E0 4F E0 CF E0 2A E0 4F E0 CF E0 AAHome E0 47 E0 C7 E0 2A E0 47 E0 C7 E0 AAIns E0 52 E0 D2 E0 2A E0 52 E0 D2 E0 AALeft arrow E0 4B E0 CB E0 2A E0 4B E0 CB E0 AAPgDn E0 51 E0 D1 E0 2A E0 51 E0 D1 E0 AAPgUp E0 49 E0 C9 E0 2A E0 49 E0 C9 E0 AARight arrow E0 4D E0 CD E0 2A E0 4D E0 CD E0 AAUp arrow E0 48 E0 C8 E0 2A E0 48 E0 C8 E0 AA

Key |--Left Shift Pressed--. |--Right Shift Pressed--. Make Break Make Break

Del E0 AA E0 53 E0 D3 E0 2A E0 B6 E0 53 E0 D3 E0 36Down arrow E0 AA E0 50 E0 D0 E0 2A E0 B6 E0 50 E0 D0 E0 36End E0 AA E0 4F E0 CF E0 2A E0 B6 E0 4F E0 CF E0 36Home E0 AA E0 47 E0 C7 E0 2A E0 B6 E0 47 E0 C7 E0 36Ins E0 AA E0 52 E0 D2 E0 2A E0 B6 E0 52 E0 D2 E0 36Left arrow E0 AA E0 4B E0 CB E0 2A E0 B6 E0 4B E0 CB E0 36PgDn E0 AA E0 51 E0 D1 E0 2A E0 B6 E0 51 E0 D1 E0 36PgUp E0 AA E0 49 E0 C9 E0 2A E0 B6 E0 49 E0 C9 E0 36Right arrow E0 AA E0 4D E0 CD E0 2A E0 B6 E0 4D E0 CD E0 36Up arrow E0 AA E0 48 E0 C8 E0 2A E0 B6 E0 48 E0 C8 E0 36/ E0 AA E0 35 E0 B5 E0 2A E0 B6 E0 35 E0 B5 E0 36

- The PS/2 models have three make/break scan code sets. The first set matches the PC & XT make/break scan code set and is the one listed here. Scan code sets are selected by writing the value F0 to the keyboard via the 8042 (port 60h). The following is a brief description of the scan code sets (see the PS/2 Technical Reference manuals for more information on scan code sets 2 and 3):

/ set 1, each key has a base scan code. Some keys generate extra scan codes to generate artificial shift states. This is similar to the standard scan code set used on the PC and XT./ set 2, each key sends one make scan code and two break scan codes bytes (F0 followed by the make code). This scan code set is available on the IBM AT also./ set 3, each key sends one make scan code and two break scan codes bytes (F0 followed by the make code) and no keys are altered by Shift/Alt/Ctrl keys./ typematic scan codes are the same as the make scan code

- Some Tandy 1000's do not handle Alt key combinations when multiple shift keys are pressed. The Alt-Shift-H combination loses the Alt.- extended keys like (F11, F12) can only be read with systems that

have extended keyboard BIOS support (or INT 9 extensions); to read these special keys on these systems INT 16,10 must be used

********************************************************************************* GRLDR Error messages *********************************************************************************

1. Missing MBR-helper.

The helper function in the sectors that immediately follow the MBR isnot present, or it has been erased by a virus or by Windows XP/Vista.

Run the bootlace.com utility to fix the problem.

2. Buggy BIOS!

Your BIOS is too buggy. It even has no support for INT13/AH=8.

No solution except flashing your BIOS. Buggy BIOSes will encountermore and more problems with grub4dos in the future.

3. This partition is NTFS but with unknown boot record. Please installMicrosoft NTFS boot sectors to this partition correctly, or create anFAT12/16/32 partition and place the same copy of GRLDR and MENU.LST there.

The boot record was changed or erased by Microsoft Windows XP ServicePack 2.

You may install the old boot record introduced with the original cleanWindows 2K/XP. As another solution, you may create an FAT partitionfor your system, and copy GRLDR and your MENU.LST to its root dir.

While the startup code of grldr might fail to load GRLDR in NTFSpartitions, it always successfully loads GRLDR in FAT partitions(andeven in ext2/ext3 partitions).

Note that NTLDR only loads the startup code of grldr(i.e., the leading16 sectors of grldr), not the whole grldr file.

Thus, C:\GRLDR must exist(here C: can be NTFS), since it is used forBOOT.INI and NTLDR. If C: is NTFS, X:\GRLDR should exist as well,where X: stands for a certain FAT partition.

********************************************************************************* Known BIOS bugs *********************************************************************************

1. Some newer Dell machines have no int13/AH=43h support. You may encounterfailure when trying to write-access an emulated disk.

Note: This bug is serious! The old "root+setup" installation method(in real mode grub environment) uses INT13 to write the first sectorof stage2. It will fail for the buggy DELL machine when stage2 isaccessed with LBA mode.

2. Some buggy BIOSes won't boot bootable.iso(See above).(qemu can boot it fine)

3. Some newer Dell machines violently destroyed the interrupt vectors for

hardware IRQs and will hang the machine when running GRUB.EXEfrom DOS. You may try again with BADGRUB.EXE.

4. Reports say some BIOSes will function abnormally after GRUB.EXE is startedby kexec of Linux. Some machines reportedly hang. Some othersreportedly cannot access USB drives.

********************************************************************************* Known Problems *********************************************************************************

1. Running GRUB.EXE from a DOS box of Windows 9x/Me could hang themachine, especially for some systems with USB support. You mayencounter the same problem when running GRUB.EXE through KEXEC underLinux.

Note: You don't have to run GRUB.EXE from protected mode of Win9x, whichcould hang the machine; Instead, you usually want to run GRUB.EXEafter you have done a "Restart the computer in MS-DOS mode", whichis safe enough.

2. The default chainloader action will keep A20 on. Some buggy DOS XMSmemory managers could hang the machine. You may use the --disable-a20option in the chainloader line and try again. Anyway, you should avoidusing those buggy memory managers.

3. THTF BIOS L4S5M Ver 1.1a(dated 2002-1-10) has a buggy int15 whichcauses hang at the boot of a multi boot kernel(memdisk for example).

4. A Chinese DOS system software, the TechWay SCS, will not work withnewer versions of GRUB.EXE. In general, TSRs that take antitrackingmeasures will not work with GRUB.EXE any more.

********************************************************************************* List of binary files and their corresponding source files *********************************************************************************

binary file main source file other included source or binary files------------- ---------------- -------------------------------------

bootlace.com bootlacestart.S bootlace.inc, grldrstart.S

grldr grldrstart.S pre_stage2(binary, See note below)

grldr.mbr mbrstart.S grldrstart.S

grub.exe dosstart.S pre_stage2(binary, See note below)

hmload.com hmloadstart.S

-----------------------------------------------------------------------------

Note: pre_stage2 is the main body of GNU GRUB and it is simply appended togrldrstart/dosstart in binary format to form our grldr/grub.exe.

Note: The GRUB file(WITHOUT .EXE suffix) is a static-linked ELF executableprogram for Linux, normally called the GRUB Shell. The GRUB Shell is a boot-manager, but not a boot-loader(the "boot" command won't work in GRUB Shell).

GRUB.EXE(with KEXEC) can be used as a bootloader running directly under Linux.

********************************************************************************* Memory Layout for Quiting to DOS from GRUB.EXE *********************************************************************************

The quit command is implemented to return to DOS in the instance that GRUB.EXEis started off DOS.

1. Before GRUB.EXE transfers control to pre_stage2, it will copy 640KB ofconventional memory to physical address 0x200000(i.e., 2MB), and write 4 longintegers immediately follows the backup copy of the conventional memory:

At 0x2A0000: 0x50554B42, it is the "BKUP" signature.

At 0x2A0004: Gate A20 status under DOS: non-zero means A20 on;zero means A20 off. Update: A20 always on, see below.

At 0x2A0008: high word is boot-CS, low word is boot-IP. The quitcommand uses this entry point to return to DOS.

At 0x2A000C: CheckSum: the sum of all long integers in the memoryrange from 0x200000 to 0x2A000F is 0.

2. If the above memory structure is corrupted by a grub command, the quitcommand will issue an error message and refuse to exit from grub.

3. Because GRUB may corrupt extended memory, you should better avoid usingextended memory under DOS before running GRUB.EXE.

4. Gate A20 will be enabled by GRUB.EXE. Hopefully this would hurt nothing.

********************************************************************************* Memory usage in conventional/low memory area *********************************************************************************

1. boot.c, fsys_reiserfs.c: 8K below 0x68000.

2. fsys_ext2fs.c, fsys_minix.c: 1K below 0x68000.

3. fsys_jfs.c: 4K + 256 bytes below 0x68000.

4. fsys_reiserfs.c: 202 bytes at 0x600.

5. fsys_xfs.c: 188 bytes at 0x600.

6. fsys_xfs.c: (logical block size) bytes below 0x68000.

7. geometry tune: 0x50000 - 0x5ffff.

********************************************************************************* Command-line Length about GRUB.EXE *********************************************************************************

GRUB.EXE now can be started in CONFIG.SYS with the **DEVICE** command:

DEVICE=grub.exe [--config-file="FILENAME_OR_COMMANDS"]

1. If GRUB.EXE is invoked with DEVICE command and FILENAME_OR_COMMANDS is acollection of some GRUB commands separated by semi-colon, then the length of

FILENAME_OR_COMMANDS can be nearly 4KB ----Supprise? But true! MS-DOS 7+even allows a much longer line, but 4KB seems enough for our use of GRUB.EXE.This is very useful when we want to embed a big menu into the command line.Note that GRLDR hasn't yet supported any command-line arguments.

2. If GRUB.EXE is invoked with INSTALL command, the option length has a limitof 80 characters(including the leading "--config-file=" part). An overflow mayhang up MS-DOS immediately.

3. If GRUB.EXE is invoked with SHELL command, the option length has a limit of126 characters(including the leading "--config-file=" part). Overflow won'thang up MS-DOS, but the line will be cut short. This limit is the same as thatin the console-DOS-prompt or in a BAT file.

4. The DOS editor EDIT does not allow to create a line of 4KB long. So useanother editor, for example, vi for Linux, please.

5. The DEVICE=GRUB.EXE line can be used together with other DEVICE commandssuch as DEVICE=HIMEM.SYS and DEVICE=EMM386.EXE. The GRUB.EXE line shouldoccur before the EMM386.EXE line in order to avoid the rejection by EMM386.Update: Since 0.4.2, GRUB.EXE works well even after EMM386.EXE is loaded.

6. In any case mentioned above, you can return back to DOS by quit command.

7. Memory usage about command-line menu: The 4KB command-line menu starts atphysical address 0x0800 and ends at 0x17FF.

********************************************************************************* New Syntax for the DEFAULT/SAVEDEFAULT Commands *********************************************************************************

In addition to the original usage of "default NUM" and "default saved", nowthere is a new usage of "default FILE", like this:

default (hd0,0)/default

Note that FILE must have a valid DEFAULT file format. A sample DEFAULT fileis included in the release. You may copy it to wherever you like, but youshould avoid modifying its content manually. The DEFAULT file may be usedin this way:

(1) First, you should copy a default file with valid format to somewhere inyour operating system.

(2) Secondly, you should use the "default FILE" command of GRUB to announcethe use of FILE as our new default file for being written by "savedefault".

(3) Then, you may use "savedefault" command to save the desired entry numberinto this new default file.

(4) OK, at next boot, you may read the saved entry number by using the same"default FILE" command as mentioned in above (2).

And the SAVEDEFAULT command now accept an options `--wait=T', like this:

savedefault --wait=5

If `--wait=T' is specified and T is non-zero, savedefault will promptthe user with a message just before it writes to disk. The write operationwill be cancelled in T seconds if the `Y' key was not pressed.

Here is a sample menu.lst file:

#--------------------begin menu.lst---------------------------------------color black/cyan yellow/cyantimeout 30default /default

title find and load NTLDR of Windows NT/2K/XPfind --set-root /ntldrchainloader /ntldrsavedefault --wait=2

title find and load CMLDR, the Recovery Console of Windows NT/2K/XPfallback 2find --set-root /cmldrchainloader /cmldr###################################################################### write string "cmdcons" to memory 0000:7C03 in 2 steps:###################################################################### step 1. Write 4 chars "cmdc" at 0000:7C03write 0x7C03 0x63646D63# step 2. Write 3 chars "ons" and an ending null at 0000:7C07write 0x7C07 0x00736E6Fsavedefault --wait=2

title find and load IO.SYS of Windows 9x/Mefind --set-root /io.syschainloader /io.syssavedefault --wait=2

title floppy (fd0)chainloader (fd0)+1rootnoverify (fd0)savedefault --wait=2

title find and boot Linux with menu.lst already installedfind --set-root /sbin/initsavedefault --wait=2configfile /boot/grub/menu.lst

title find and boot Mandriva with menu.lst already installedfind --set-root /etc/mandriva-releasesavedefault --wait=2configfile /boot/grub/menu.lst

title back to dossavedefault --wait=2quit

title commandlinesavedefault --wait=2commandline

title rebootsavedefault --wait=2reboot

title haltsavedefault --wait=2

halt#--------------------end menu.lst---------------------------------------

Note 1: The file DEFAULT must exist and have a proper format as stated above.Or else, the default/savedefault commands won't function well.

Note 2: The file DEFAULT which is in the same dir as a certain MENU.LST fileis called associated with the MENU.LST file.

Note 3: The associated DEFAULT file will take effect automatically if thereare no `default' commands present.

Note 4: Just before a menu file gains control(e.g., it is the associatedMENU.LST of a GRLDR file, or it was specified via`grub.exe --config-file=(DEVICE)/PATH/YOUR_MENU_FILE', or it wasspecified by the `configfile' command of grub), its associatedDEFAULT file will be used if present, until an explicit `default'command is encountered.

********************************************************************************* The New `cdrom' Command Syntax *********************************************************************************

1. Initialize the ATAPI CDROM devices:

grub> cdrom --init

This will display the number of atapi cdroms found: atapi_dev_count

2. Stop the ATAPI CDROM devices:

grub> cdrom --stop

This will set atapi_dev_count to 0.

3. Add IO ports for searching the atapi cdrom devices. For example:

grub> cdrom --add-io-ports=0x03F601F0

After running `cdrom --init' and `map --hook', the cdroms can be accessedthrough devices (cd0), (cd1), ...

Note 1: If the system does not fully support the ATAPI CD-ROM specifications,you will encounter failure when trying to access the (cdX) devices.

Note 2: After doing a `cdrom --stop', you should do a `map --unhook'. Ofcourse you may `map --hook' again if there are mapped drives.

Note 3: After adding IO ports, you should do a `map --unhook' followed by a`cdrom --init' and then followed by a `map --hook'.

By default, these ports are used for searching cdroms(so they needn'tbe added):

0x03F601F0, 0x03760170, 0x02F600F0,0x03860180, 0x6F006B00, 0x77007300.

Note 4: The BIOS might have offered a cdrom interface. It would be (cd). After`cdrom --init' and `map --hook', we might have our (cd0), (cd1), ...available. It is likely that one of them could access the same media

as the BIOS-offered (cd).

Note 5: You may access the (cd) and (cdX)'es in the blocklist way. Example:

cat --hex (cd0)16+2

The cdrom sectors are big sectors with a size of 2048 bytes.

Note 6: The iso9660 filesystem driver has Rock-Ridge extension support, buthas no Joliet extension support. So you may encounter failure whenyou attempt to read files on a Joliet CD.

Note 7: The (cd) or (cdX)'es can be booted now. Examples:

chainloader (cd)boot

chainloader (cd0)boot

chainloader (cd1)boot

You should already have access to the CD sectors before you canchainload it.

********************************************************************************* About the New `setvbe' Command *********************************************************************************

Gerardo Richarte contributed the `setvbe' code and the following comment:

New command is `setvbe', and can be used to change the video modebefore executing the kernel.

For example, you can do

setvbe 1024x768x32

this will scan the list of available modes and set it, andautomatically append a `video=' option to each subsequent kernelcommand-line. The appended `video=' option is like this:

video=1024x768x32@0xf0000000,4096

where 0xf0000000 is the video framebuffer address as reported by vbe,and 4096 is the size of a scanline in bytes (also as reported by vbe).

This is really useful if you want to give some graphics support to yourOS, but you don't want to implement any video functionality other thanwriting a pixel to video memory.

********************************************************************************* About the DOS utility `hmload' *********************************************************************************

This program was written by John Cobb (Queen Mary, University of London).

John Cobb's note:

To make use of the ram drive feature I wrote a program `hmload' to loadan arbitrary file to an arbitrary address in high memory. The programis not very sophisticated and relies on XMS to turn on the A20 line.(Also one must be very careful to steer clear of any areas of memoryalready in use).

Under Linux we generated a disk image `dskimg' (with the kernel andInitrd and a partition table).

Using this our boot procedure looked something like this:

hmload -fdskimg -a128fixrb<unload network drivers>grub

map --ram-drive=0x81map --rd-base=0x8000000map --rd-size=0x400000root (rd,0)kernel /kernel root=/dev/ram0 rw ip=bootp ramdisk_size=32768 ...initrd /initrdboot

See http://sysdocs.stu.qmul.ac.uk/sysdocs/Comment/GrubForDOS/ for details.

Update 2007-12-05:

Now the MAP command can handle gzipped (rd) image. One can use thisfeature with the hmload utility. For example,

step 1. Load the gzipped image under DOS at a relatively low address:

hmload -fdskimg.gz -a16

step 2. Unload network drivers.

step 3. Run GRUB.EXE.

step 4. At the grub prompt, run these commands:

map --rd-base=0x1000000 # set rd-base address to be 16Mmap --rd-size=<the accurate size of dskimg.gz in bytes>map (rd)+1 (hd0) # This will decompress (rd) and place

# the decompressed image at the top end# of the extended memory. The (rd)+1# here has special meaning and stands# for the whole (rd) device. You must# use (rd)+1 instead of (rd).

map --hookroot (hd0,0)kernel /kernel root=/dev/ram0 rw ip=bootp ramdisk_size=32768 ...initrd /initrdmap --unhookmap (hd0) (hd0) # Delete the map; this is needed.boot

******************************************************************************

*** Notes on the use of stack *********************************************************************************

The protected-mode and real-mode stack are merged at physical address 0x2000.

All functions should use at most 2K stack space(0x1800-0x2000). So eachsubfunction should use as little stack as possible to avoid stack-overflow.

Don't use recursive functions because they could expend too much stack space.

The original protected mode stack at 0x68000(expand-down) is free now and canbe reused for any purposes.

********************************************************************************* A bug was found in the CDROM driver *********************************************************************************

It seems the cdrom must be connected as the master device of an IDE controller.

If cdrom is slave, the driver will fail to read the cdrom sectors. Hope someone

could fix this problem.

********************************************************************************* BIOS and the (cd) drive *********************************************************************************

When BIOS boots a no-emulation-mode bootable CD-ROM, it allocates a BIOS drivenumber to the CD. If the boot image of the CD-ROM is grldr or stage2_eltorito,then GRUB can access the CD-ROM media through the drive number allocated byBIOS. The device name of the CD-ROM is (cd).

BIOS can allocate a BIOS drive number to a no-emulation-mode CDROM even whenthe CDROM is not bootable. QEMU has done so. At boot time, GRUB4DOS willsearch drives 0x80-0xFF for a possible no-emulation-mode CDROM drive allocatedby BIOS. So if BIOS offered a CDROM interface of int13 EBIOS functions 41h-4Eh,then the (cd) device will be automatically available in GRUB4DOS.

********************************************************************************* The way of disk emulation changed greatly *********************************************************************************

The way of disk emulation has changed greatly since 0.4.2 final. Please don'tmix newer versions with older versions when disk emulation features are used.

The newer versions won't automatically unhook emulations established in aprevious grub4dos environment. The GRUB.EXE of an older version willautomatically dismiss emulations established earlier, before transferringcontrol to the main grub program(i.e., pre_stage2).

********************************************************************************* FreeDOS EMM386 v2.26 (2006-08-27) VCPI problem *********************************************************************************

The VCPI function "AX=DE0Ch - Switch From Protected Mode to V86 Mode" ofFreeDOS EMM386 v2.26 was not implemented properly(it always hangs). As an

alternative, you can use Microsoft's EMM386 instead.

Even while emm386 is running, grub.exe can be started. But if you try to quitto DOS from grub4dos by using the `quit' command, the VCPI function DE0C willbe called. If EMM386 is of Microsoft, everything goes ok. If EMM386 is ofFreeDOS, the machine will hang.

********************************************************************************* New options for map were added *********************************************************************************

Along with 0.4.2 final, there are two new options for the map command. Theyare --safe-mbr-hook=SMH and --int13-scheme=SCH. Both are related with diskemulation for use(as smoothly as possible) in the Win9x environment.

SMH can take either of the two values 0 and 1. By default, SMH is 1. If youencountered problems of disk emulation under Win9x, you may insert a line of

map --safe-mbr-hook=0

before the `boot' command and try again.

Also SCH may take either 0 or 1 at present. By default, SCH is 1. If youencountered disk emulation problems under Win9x, you may insert a line of

map --int13-scheme=0

before the `boot' command and try again.

Note by the way. Like --safe-mbr-hook and --int13-scheme, the MAP command hasa few other options that are used for setting global variables. They are here:

map --floppies=M

M can be 0, 1, or 2. MAP will set a proper value at 0040:0010 by using M.

map --harddrives=N

N can be between 0 and 127(inclusive). MAP will set 0040:0075 to N.

map --memdisk-raw=RAW

RAW default to 1. If RAW=0, `int15/ah=87h' will be used to access memdrives.

map --ram-drive=RD

RD default to 0x7F which is a floppy. If the RAM DRIVE is a hard drive image(with partition table in the first sector), you should set RD >= 0x80 and RD< 0xA0.If the RAM DRIVE is a cdrom image, you should set 0xA0<= RD <= 0xff.

map --rd-base=ADDR

map --rd-size=SIZE

ADDR specifies the physical base address of the ramdisk image. SIZE specifiesthe size in bytes of the ramdisk image. ADDR default to 0. SIZE is also defaultto 0, but a size of 0 means 4GB, not a zero-long disk. The RAM DRIVE can beaccessed in the GRUB environment using the (rd) device.

********************************************************************************* About the new map option --in-situ *********************************************************************************

--in-situ is used with hard drive images or hardrive partitions. With anin-situ map, we can typically use a logical partition as a primary partition.

In-situ map is a whole drive map. It only virtualize the partition table andthe number of hidden sectors in the BPB of the DOS Boot Record.

While disk emulation may encounter various problems with win9x, the in-situ mapworks fine with win9x.

Note that --in-situ will not change the real partition table.

Example:

map --in-situ (hd0,4)+1 (hd0)

********************************************************************************* The PARTNEW Command Syntax *********************************************************************************

Besides the mappings in the above section, you may instead choose to create anew primary partition with the PARTNEW command. PARTNEW can generate a primarypartition entry (in the partition table) for a logical partition.

For example,

partnew (hd0,3) 0x07 (hd0,4)+1

where the file (hd0,4)+1 stands for the whole partition (hd0,4). This commandwill create a new primary partition (hd0,3) whose type is 0x07 and whosecontents/data is the same as that of the logical partition (hd0,4).

Just like a whole logical partition, a contiguous partition image file canalso be used with PARTNEW:

partnew (hd0,3) 0x00 (hd0,0)/my_partition.img

The type 0x00 indicates a type-auto-detection of the image MY_PARTITION.IMG.The above command will create a new primary partition (hd0,3) with a propertype and with contents/data being exactly that of the contiguous file(hd0,0)/my_partition.img.

PARTNEW will automatically correct the "hidden sectors" in the BPB and themodification will be permanent. And PARTNEW modifies the partition tablepermanently.

In addition to creating new partition entries, PARTNEW can also be used todelete(erase, or wipe) a primary partition entry. For example,

partnew (hd0,3) 0 0 0

which will empty the last entry in the partition table in MBR. Generally,you should use the form of "partnew PARTITION 0 0 0" to erase the entry.Note that only the entry would be erased, and the data stored in the partitionwill not be touched.

********************************************************************************* Newly implemented operators `&&' and `||' *********************************************************************************

This implementation is very simple. It does not handle operator nesting.

Usage of `&&':

command1 && command2

Description:

If command1 returns true, then command2 will be executed.

Usage of `||':

command1 || command2

Description:

If command1 returns false, then command2 will be executed.

Examples:

is64bit && default 0is64bit || default 1

2010-11-04Add new operators "|", ">" , ">>"

Usage:command1 | command2

command > fileorcommand >> file

Node: The file must already exist, GRUB4DOS can not create file or change the file size.Examples:

cat /test.txt > /abcd.txt

2013-03-20Add new operation ";;",multiple commands on one line

Usage:command1 ;; command2 ;; command..

Description:Execute multiple commands in sequence without error warning.

2013-04-01Add new operation "&;" and "|;"

********************************************************************************* Three new commands is64bit, errnum and errorcheck *********************************************************************************

is64bit and errnum retrieve the value of is64bit and errnum respectively.

errorcheck controls whether or not the error will be handled. By default,

errorcheck is on, and menu script execution will stop on error. If errorcheckis off, the script will continue to execute upto a boot command. A boot commandwill turn the errorcheck on.

********************************************************************************* Use numeric keys to select a menu entry *********************************************************************************

If, for example, you intend to goto entry #25, you may press 2 followed by 5.

********************************************************************************* Use the INSERT key to debug step by step at startup *********************************************************************************

Some buggy machines could fail to enter grub4dos environment. They might hangor reboot unexpectedly. Press INSERT as quickly as possible on startup, andyou can get a chance to single-step the boot process and see how far it cango, and then report bugs.

********************************************************************************* The debug command syntax has been changed *********************************************************************************

The DEBUG command now can be used to control the verbosity of command output:

debug [ on | off | normal | status | INTEGER ]

0 or off for silent1 or normal for normal2 to 0x7FFFFFFF or on for verbose

********************************************************************************* GRUB4DOS and Windows Vista *********************************************************************************

First, use the following command to create a boot entry:

bcdedit /create /d "GRUB for DOS" /application bootsector

The result will look like this:

The entry {05d33150-3fde-11dc-a457-00021cf82fb0} was successfully created.

The long string {05d33150-3fde-11dc-a457-00021cf82fb0} is the id for thisentry.

Then, use the following commands to set boot parameters:

bcdedit /set {id} device bootbcdedit /set {id} path \grldr.mbrbcdedit /displayorder {id} /addlast

Please replace {id} with the actual id returned from the previous command.

Finally, copy GRLDR.MBR to C:\ or wherever your boot drive is, and copy GRLDRand menu.lst to the root directory of any FAT16/FAT32/EXT2/NTFS partition.

Note: A boot partition should be the active primary partition with BOOTMGR inside. The `device boot' indicates grldr.mbr should be in the boot partition.

Lianjiang has written down a script to automate the tasks:

@echo offrem by lianjiangclsecho.echo Please run as administratorecho.pauseset gname=GRUB for DOSset vid=set timeout=5bcdedit >bcdtemp.txttype bcdtemp.txt | find "\grldr.mbr" >nul && echo. && echo BCD entry ex

isting, no need to install. && pause && goto exitbcdedit /export "Bcd_Backup" >nulbcdedit /create /d "%gname%" /application bootsector >vid.inifor,/f,"tokens=2 delims={",%%i,In (vid.ini) Do (

set vida=%%i)for,/f,"tokens=1 delims=}",%%i,In ("%vida%") Do (

set vid={%%i})echo %vid%>vid.inibcdedit /set %vid% device boot >nulbcdedit /set %vid% path \grldr.mbr >nulbcdedit /displayorder %vid% /addlast >nulbcdedit /timeout %timeout% >nulif exist grldr.mbr copy grldr.mbr %systemdrive%\ /y && goto exitecho.echo Please copy grldr.mbr to %systemdrive%\echo.pause:exitdel bcdtemp.txt >nul

-------------------------------------------------------------------Update: Fujianabc pointed out that

bcdedit /set %vid% device boot >nul

should be changed to

bcdedit /set %vid% device partition=%SystemDrive% >nul-------------------------------------------------------------------

You still need to copy grldr yourself.

Notice: It's possible to modify the BCD entry from a different OS, you justneed to specify the location of BCD:

bcdedit /store D:\boot\BCD ...

Notice: These commands need elevated privileges, they should be used insidecmd.exe which is started with "Run as administrator".

Notice: People has reported that some version of Vista doesn't supportcreating file in C:\ with no extension, even with administrator privileges.This means grldr can't be placed in C:\. You can solve this by either copygrldr to another partition, or rename grldr to something like grub.bin. Pleasesee the following section on how to do this.

********************************************************************************* How to rename grldr *********************************************************************************

grldr and grldr.mbr use internal boot file name to decide which file to load,so if you want to change the name, you must also change the embeded setting.You can do this with the help of grubinst, which can be downloaded at:

http://download.gna.org/grubutil/

grubinst can generate customized grldr.mbr:

grubinst -o -b=mygrldr C:\mygrldr.mbr

grubinst can also edit existing grldr/grldr.mbr:

grubinst -e -b=mygrldr C:\mygrldr

grubinst -e -b=mygrldr C:\mygrldr.mbr

In this case, you must use a grubinst that is compatible with the version ofgrub4dos, otherwise the edit will fail.

So, in order to load mygrldr instead of grldr, you can use one of thefollowing methods:

1. Use customized grldr.mbr to load mygrldr. In this case, you need to changethe embeded boot file name in grldr.mbr. The name of grldr.mbr can be changedat will.

2. Use mygrldr directly. In this case, you need to change the embeded bootfile name in mygrldr to match its new name.

Notice: The boot file name must conform to the 8.3 naming convention.

********************************************************************************* PXE device *********************************************************************************

If PXE service is found at startup, GRUB4DOS will create a virtual device(pd), through which files from the tftp server can be accessed. You can setupa diskless boot environment using the following steps:

Client side

You need to boot from PXE ROM.

Server side

You need to configure a dhcp server and a tftp server. In the dhcp server, usegrldr as boot file.

You may also want to load a different menu.lst for different client. GRUB4DOSwill scan the following location for configuration file:

[/mybootdir]/menu.lst[/mybootdir]/menu.lst/01-88-99-AA-BB-CC-DD[/mybootdir]/menu.lst/C000025B[/mybootdir]/menu.lst/C000025[/mybootdir]/menu.lst/C00002[/mybootdir]/menu.lst/C0000[/mybootdir]/menu.lst/C000[/mybootdir]/menu.lst/C00[/mybootdir]/menu.lst/C0[/mybootdir]/menu.lst/C[/mybootdir]/menu.lst/default

Here, we assume the network card mac for the client machine is88:99:AA:BB:CC:DD, and the ip address is 192.0.2.91 (C000025B). /mybootdir isthe directory of the boot file, for example, if boot file is /tftp/grldr, thenmybootdir=tftp.

If none of the above files is present, grldr will use its embeded menu.lst.

This is a menu.lst to illustrate how to use files from the tftp server.

title Create ramdisk using mapmap --mem (pd)/floppy.img (fd0)map --hookrootnoverify (fd0)chainloader (fd0)+1

title Create ramdisk using memdiskkernel (pd)/memdiskinitrd (pd)/floppy.img

You can see that the menu.lst is very similar to normal disk boot, you justneed to replace device like (hd0,0) with (pd).

There are some differences between disk device and pxe device:

1. You can't list files in the pxe device.

2. The blocklist command will not work with a file in the pxe device.

3. You must use --mem option if you want to map a file in the pxe device.

When you use chainloader to load file from the pxe device, there is a optionyou can use:

chainloader --raw (pd)/BOOT_FILE

Option --raw works just like --force, but it load file in one go. This canimprove performance in some situation.

You can use the pxe command to control the pxe device.

1. pxe

If used without any parameter, pxe command will display currentsettings.

2. pxe blksize N

Set the packet size for tftp transmission. Minimum value is 512,maximum value is 1432. This parameter is used primarily for very oldtftp server where packet larger than 512 byte is not supported.

3. pxe basedir /dir

Set the base directory for files in the tftp server. If

pxe basedir /tftp

then all files in the pxe device is related to directory /tftp, forexample, (pd)/aa.img correspond to /tftp/aa.img in the server.

The default value of base directory is the directory of the boot file,for example, if boot file is /tftp/grldr, then default base directoryis /tftp.

4. pxe keep

Keep the PXE stack. The default behaviour of GRUB4DOS is to unloadthe PXE stack just before it exits.

5. pxe unload

Unload the PXE stack immediately.

********************************************************************************* New Feature of Relative Path Support *********************************************************************************

Use the `root' or `rootnoverify' command to specify the `working directory'.

For example:

root (hd0,0)/boot/grub

This specifies that the working dir is (hd0,0)/boot/grub. So all subsequentfilenames of the form "/..." will actually refer to (hd0,0)/boot/grub/...

That is to say:

cat /menu.lst

will be equivalent to

cat (hd0,0)/boot/grub/menu.lst

********************************************************************************* Notation For The Current Root Device *********************************************************************************

The notation `()' can be used to access the current root device. You may use`find --set-root ...' to set the current root device, but the find command

does not set the `working dir' of the root device. In this case you shoulduse `()' to set the working dir after the find command:

root ()/boot/grub

Update 2008-05-01:

FIND can also set the `working directory' now. For example:

find --set-root=/tmp /boot/grub/menu.lst

It is equivalent to this pair of commands:

find --set-root /boot/grub/menu.lstroot ()/tmp

********************************************************************************* The new map option --a20-keep-on *********************************************************************************

Along with 0.4.3 final, map has a new option --a20-keep-on which is related toA20 control after a memdrive sector access. Usage:

map --a20-keep-on=0

It should be used before the "map --hook" command.

By default, A20 will be always on after an RAM INT13 sector access. If"map --a20-keep-on=0" is used, the A20 status after the INT13 call will be thesame as that before the INT13 call.

********************************************************************************* The CDROM emulation (virtualization) *********************************************************************************

The CDROM emulation is sometimes called ISO emulation. Here is an example:

map (hd0,0)/myiso.iso (hd32)map --hookchainloader (hd32)boot

if myiso.iso is not contiguous and you have enough memory, add a --mem option:

map --mem (hd0,0)/myiso.iso (hd32)map --hookchainloader (hd32)boot

Note: (hd32) is a grub drive number equivalent to (0xA0). If a virtual drive isspecified with a drive number greater than or equal to 0xA0, then it will betreated as a cdrom (i.e., with 2048-byte big sectors).

Like normal disk emulations, the CDROM emulation also (mainly) works withreal-mode OSes. After a protected-mode OS kernel (such asWinNT/2K/XP/VISTA/LINUX) gains control, the OS would have no ability to accessthe virtual CDROM through BIOS int13.

DOS/Win9x users may google for ELTORITO.SYS and use it in CONFIG.SYS as adevice driver for the virtual cdrom.

Example usage of eltorito.sys in CONFIG.SYS:

device=eltorito.sys /D:oemcd001

Corresponding MSCDEX command which can be placed in AUTOEXEC.BAT:

MSCDEX /D:oemcd001 /L:D

Due to some bugs found in eltorito.sys, the driver could fail to load. If youencounter such problems, then you may replace (hd32) with (0xFF) for thevirtual cdrom drive number and try again.

********************************************************************************* The New Command CHECKRANGE *********************************************************************************

Checkrange checks whether or not the return value of a command is in thespecified range or ranges.

Usage: checkrange RANGE COMMAND

Here are some examples for RANGE:

3 is a range containing only the number 33:3 is equivalent to 33:8 is a range containing the numbers 3, 4, 5, 6, 7, 83,4,5,6,7,8 is equivalent to 3:83:5,6:8 is also equivalent to 3:83,4:7,8 is also equivalent to 3:8

Note: You should not insert spaces into a range.

Here is an example showing where the checkrange can be used:

checkrange 0x05,0x0F,0x85 parttype (hd0,1) || hide (hd0,1)

which means: if (hd0,1) is not an extended partition, then hide it.

********************************************************************************* The New Command TPM *********************************************************************************

The "tpm --init" uses 512-byte data at 0000:7C00 as buffer to initialise TPM.

Before you boot VISTA's BOOTMGR, you might have to use the "tpm --init"command on some machines. Normally you want to issue the "tpm --init" commandafter a CHAINLOADER command.

********************************************************************************* Delimitors or comments between titles *********************************************************************************

It is possible to use titles as delimitors or comments. A title(or menu item)is called unbootable if all of its menu commands are not boot-sensitive.

The following commands are boot-sensitive(and others are not boot-sensitive):

bootbootpchainloaderconfigfileembedcommandlinehaltinstallkernelpxequitrebootsetup

An unbootable title will be skipped when the user presses the Up Arrow or DownArrow keys. Even the unbootable menu item can get accessed(and executed) byusing the Left Arrow and/or Right Arrow keys. Examples:

title This is an UNBOOTABLE entry(so this line is also a comment)pause --wait=0 This title is a comment. Nothing to do.pause --wait=0 You can use non-boot-sensitive commands herepause --wait=0 of any kind and as many as you would like.helphelp roothelp chainloaderhelp parttypeclear

title ------------------------------------------------------------pause --wait=0 This title is a delimitor. Nothing to do.pause --wait=0 You can use non-boot-sensitive commands herepause --wait=0 of any kind and as many as you would like.clearhelphelp boot

title ============================================================pause --wait=0 This title is a delimitor. Nothing to do.pause --wait=0 You can use non-boot-sensitive commands herepause --wait=0 of any kind and as many as you would like.helpclearhelp pause

title ************************************************************pause --wait=0 This title is a delimitor. Nothing to do.pause --wait=0 You can use non-boot-sensitive commands herepause --wait=0 of any kind and as many as you would like.help kernelhelpclear

Note: An unbootable menu item must contain at least one command. If thereare no commands for a title, the title will be simply discarded and disappear.

********************************************************************************* Bifurcate drives ***

******************************************************************************

Some machines apply different actions to a drive between CHS and LBA mode.When you read sectors using standard BIOS call int13/AH=02h, you might findout the drive is a floppy. But when you read sectors using extended BIOScall(EBIOS) int13/AH=42h, you could know the drive is a cdrom. Such a driveis called bifurcate.

A bifurcate drive can have two drive numbers: one is the normal BIOS drivenumber between 00 and FF in hexa, and this drive uses only CHS mode diskaccess(standard BIOS int13/AH=02h); the other is the normal BIOS drive number(Bitwise) OR'ed by 0x100(i.e., 256 in decimal), and this drive uses onlyLBA mode disk access(EBIOS int13/AH=42h). For example, if the drive 0x00(i.e., the first floppy) is bifurcate, then the drive (0x00) uses CHS modeto access its sectors, and the drive (0x100) uses LBA (meaning EBIOS) modeto access its sectors.

The geometry command can report the disk access mode for bifurcate drives asBIF instead of the conventional CHS or LBA.

Known bifurcate drives. Virtual PC and some real machines are found to createa bifurcate floppy drive when they boot from a floppy-emulation mode bootablecdrom. The "geometry (fd0)" will show

drive 0x00(BIF): C/H/S=...Sector Count/Size=.../512

and "geometry (0x100)" will show

drive 0x100(BIF): C/H/S=...Sector Count/Size=.../2048

Actually (0x100) can access the whole cdrom, you may "ls (0x100)/" and findyour files on the cdrom(not the files inside the booted floppy image). Ofcourse "ls (fd0)/" will list the files inside the booted floppy image.

Note that only some (real or virtual) machines have this action, otherswill not produce bifurcate drives.

********************************************************************************* GRLDR as PXE boot file *********************************************************************************

GRLDR can be used as the PXE boot file on a remote/network server. The (pd)device is used to access files on the server. When GRLDR is booted throughnetwork, it will use its preset menu as the config file. However, you may usea "pxe detect" command, which acts this way:

* First, it will search for the config file "menu.lst" in the same dir as grldr.

* Second, it will search for the config file using the hardware type (using its ARP type code) and address, all in hexadecimal with dash separators; for example, for an Ethernet (ARP type 1) with address 88:99:AA:BB:CC:DD it would search for the filename 01-88-99-AA-BB-CC-DD.

* Next, it will search for the config file using its own IP address in upper case hexadecimal, e.g. 192.0.2.91 -> C000025B. If that file is not found, it will remove one hex digit and try again. At last, it will try looking for a file named default (in lower case). As an example, if the boot file name is /mybootdir/grldr, the Ethernet MAC address is

88:99:AA:BB:CC:DD and the IP address 192.0.2.91, it will try following files (in that order):

/mybootdir/menu.lst /mybootdir/menu/01-88-99-AA-BB-CC-DD /mybootdir/menu/C000025B /mybootdir/menu/C000025 /mybootdir/menu/C00002 /mybootdir/menu/C0000 /mybootdir/menu/C000 /mybootdir/menu/C00 /mybootdir/menu/C0 /mybootdir/menu/C /mybootdir/menu/default

You cannot directly map an image file on (pd). You must map it in memory usingthe --mem option. For example,

map --mem (pd)/images/floppy.img (fd0)map --hookchainloader (fd0)+1rootnoverify (fd0)boot

One more example,

map --mem (pd)/images/cdimage.iso (0xff)map --hookchainloader (0xff)boot

********************************************************************************* New program badgrub.exe *********************************************************************************

The new program badgrub.exe is intended to serve 'bad' machines(typically someDELL models) that cannot run the normal grub.exe.

********************************************************************************* Conditional find *********************************************************************************

The new find syntax allows to find a device conditionally.

find [OPTIONS] [FILENAME] [CONDITION]

CONDITION is a normal grub command which returns TRUE or FALSE.

OPTIONS:--set-root set the current root device.--set-root=DIR set current root device and working directory to

DIR.please also see "Notation For The Current Root Device".

--ignore-cd skip search on (cd).--ignore-floppies bypass all floppies.--devices=DEVLIST specify the search devices and order.

DEVLIST u->(ud)n->(nd)

p->(pd)h->(hdx)c->(cd)f->(fdx)default: upnhcf

Example 1:

find

This will list all partitions, all floppies and the (cd).

Example 2:

find +1

This will list all devices with a known filesystem.

Example 3:

find checkrange 0xAF parttype

This will list all partitions with ID=0xAF.

Example 4:

find /ntldr checkrange 0x07 parttype

This will list all partitions with ID=0x07 and existing /ntldr.

Example 5:find --set-root /ntldr

This will set the first device it finds to current root device.

Example 6:find --set-root --devices=h /bootmgr

Same of Example 5.but search on hard disk only.

Example 7:find --set-root --devices=h makeactive --status

This will set current root device to first active partition.

********************************************************************************* How to build grldr boot images *********************************************************************************

1. build 1.44M floppy image ext2grldr.img

dd if=/dev/zero of=ext2grldr.img bs=512 count=2880mke2fs ext2grldr.imgmkdir ext2tmpmount -o loop ext2grldr.img ext2tmpcp default ext2tmpcp menu.lst ext2tmpcp grldr ext2tmpumount ext2tmpbootlace.com --floppy --chs --sectors-per-track=18 --heads=2 --start-sec

tor=0 --total-sectors=2880 ext2grldr.img

2. build 1.44M floppy image fat12grldr.img

dd if=/dev/zero of=fat12grldr.img bs=512 count=2880mkdosfs fat12grldr.imgmkdir fat12tmpmount -o loop fat12grldr.img fat12tmpcp default fat12tmpcp menu.lst fat12tmpcp grldr fat12tmpumount fat12tmpbootlace.com --floppy --chs fat12grldr.img

3. build iso9660 CDROM image grldr.iso

mkdir iso_rootcp grldr iso_rootcp menu.lst iso_rootmkisofs -R -b grldr -no-emul-boot -boot-load-size 4 -o grldr.iso iso_roo

t

********************************************************************************* Use bootlace.com to install partition boot record *********************************************************************************

Since bootlace.com has not implemented the --install-partition option, youneed to use the already implemented --floppy=PartitionNumber option instead.

Hear is a way you might want to follow:

Step 1. Get the boot sectors of the partition and save to a file MYPART.TMP.For NTFS, you need to get the beginning 16 sectors. For other type offilesystems, you only need to get one sector, but getting more sectorsis also ok.

Step 2. Run this:

bootlace.com --floppy=Y --sectors-per-track=S --heads=H --start-sector=B --total-sectors=C --vfat --ext2 --ntfs MYPART.TMP

where we suppose MYPART.TMP is for (hdX,Y) and the partition number Yshould be specified as in the --floppy=Y option.

Note that for FAT12/16/32/NTFS partitions, you can omit these options:

--sectors-per-track, --heads, --start-sector, --total-sectors, --vfat and --ext2.

For NTFS partitions, you must specify --ntfs option.

For ext2 partitions, you can omit --vfat, --ntfs and --ext2 options,but other options should be specified.

Step 3. Put MYPART.TMP back on to the boot sector(s) of your original partition(hdX,Y).

Note: Only a few file systems(FAT12/16/32/NTFS/ext2/ext3) are supported by now.

Note2: Under Linux you may directly write the partition. That is to say, Step1 and Step 3 are not needed. Simply use its device name instead of

MYPART.TMP.

Note3: grubinst has the feature of installing grldr boot code onto apartition boot area.

********************************************************************************* Use a single key to select menu item *********************************************************************************

Some machines have a simplified keyboard. The keyborad might have only thenumber keys 0 .. 9 plus a few other keys. When the menu displayed, the usercan strike a key for 8 times. When the menu handler detects the continuoussingle keypress, it will assume the user want to use this key to select a menuitem and boot. This single key will act as the RIGHT-ARROW key for the user toselect a menu item. And 5 seconds later after the user stops the keypress,the selected menu item will automatically boot. Any normal keys can be used asa single key for this purpose, except for a few functional keys like b, e,Enter, etc. Once another key is pressed, the feature of Single-Key-Selectionwill disappear immediately.

********************************************************************************* Parameter file for bootlace running under DOS *********************************************************************************

You may move all or part of the command-line arguments into a file. The filecan have multi lines. Just like SPACEs and TABs, the CRs and LFs can alsodelimit the commandline arguments in the parameter file.

Example:

bootlace < my_parafilebootlace --read-only my_mbr < my_other_options

Note: Pipes do not work. You have to use the input-redirection operator(<).

********************************************************************************* Use bootlace to create a triple MBR *********************************************************************************

This is typically used for USB drives, though it also works with hard drives.

Steps to create triple MBR:

1. Do a fresh FDISK to create a FAT12/16/32 partition starting at sector 95(in LBA, that is, the begginning sector(MBR) is sector 0).

2. Install grldr boot sector onto the boot sector of this partition. Seesection "Use bootlace.com to install partition boot record" above.

3. Get 96 sectors of the drive starting at sector 0(MBR), and save to fileMYMBR96.TMP.

4. Run bootlace.com:

bootlace.com MYMBR96.TMP

5. Put MYMBR96.TMP back onto the drive starting at MBR(sector 0).

Note: If the drive already has a triple MBR, then bootlace will cancel itand restore the original partition layout.

********************************************************************************* Use 'pxe detect' in preset-menu *********************************************************************************

Now the "pxe" command has a new subcommand "detect":

pxe detect [BLOCK_SIZE] [MENU_FILE]

BLOCK_SIZE specifies the block size for PXE. If it is not specified or it is0, then grub4dos will go through a probing process and get a proper valuefor data transfer.

MENU_FILE specifies the config file on the PXE server. If omitted, a standardconfig file in the menu.lst sub-dir will gain control. For a description onthe config files in the menu.lst sub-dir, please refer to the section"GRLDR as PXE boot file" above.If MENU_FILE starts in a "/", then the MENU_FILE on the PXE server will gaincontrol, else(if MENU_FILE does not start in a "/") no menu will be executed.

Normally you want to use a "pxe blksize ..." or a "pxe detect ..." commandbefore you access the (pd) device, since the default blocksize of 512 mightnot work on your system.

********************************************************************************* Use 'configfile' in preset-menu *********************************************************************************

Now the preset menu holds the highest priority. It will gain control prior tothe menu.lst on the boot device. If a 'configfile' command(without specifyingany file as the parameter) occurs in the menu init command group of the presetmenu, then control will go to the menu.lst on the boot device.

Note: You should better not use "configfile ANOTHER_MENU" frequently in yourmenu.lst file, because it could create infinite loop and thus hang yourcomputer.

********************************************************************************* New command 'dd' to copy files *********************************************************************************

Usage:

dd if=IF of=OF [bs=BS] [count=C] [skip=IN] [seek=OUT] [buf=ADDR] [buflen=SIZE]

Copy file IF to OF. BS is blocksize in bytes, default to 512. C is blocks tocopy, default is total blocks in IF. IN specifies number of blocks to skipwhen read, default is 0. OUT specifies number of blocks to skip when write,default is 0. Skipped blocks are not touched. Both IF and OF must exist.

Both IF and OF must have a leading device name, i.e., of the form `(...)'.You may use `()' for the current root device.

dd can neither enlarge nor reduce the size of OF, the leftover tail of IFwill be discarded. OF cannot be a gzipped file. If IF is a gzipped file,

it will be decompressed automatically when copying.

dd is dangerous, use at your own risk. To be on the safe side, you shouldonly use dd to write a file in memory.

In some cases when writing a file in a NTFS volume, dd might fail.

If you attempt to write a device or a block file that is not in memory bystarting dd in a menu, you will safely be refused :-) (Update: no restrictionsnow)

Update: New options are implemented for user defined buffer. By default,the buffer is at address 0x50000, and length is 0x10000(=64KB). You cannotspecify ADDR to be lower than 0x100000(=1MB). Besides, you must specify SIZElarger than 0x10000(=64KB). Normally you want ADDR >= 0x1000000(=16MB), andSIZE also >= 16MB. A large SIZE could speed up the progression of dd.

Update 2: From 2011-10-03 on, buffer address default at 1M. Since grub4dosreserved 32M memory for internal use on 2011-10-20, you normally want to useADDR >= 0x2000000(=32MB). Obviously you should not set ADDR and SIZE toconflict with code and data of grub4dos.

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~!!!!!!!! Caution! Both IF and OF can be a device name which stands for !!!!!!!! all the sectors on the device. Take utmost care! !!!!!!!!______________________________________________________________________!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

********************************************************************************* New command 'uuid' to identify partitions *********************************************************************************

Usage:

uuid [DEVICE] [UUID]

If DEVICE is not specified, search for filesystem with UUID in all partitionsand set the partition containing the filesystem as new root (if UUID isspecified), or just list uuid's of all filesystems on all devices (if UUID isnot specified). If DEVICE is specified, return true or false according towhether or not the DEVICE matches the specified UUID (if UUID is specified),or just list the uuid of DEVICE (if UUID is not specified).

Example 1:

find --set-root uuid () 7f95820f-5e33-4e6c-8f50-0760bf06d79c

which will find a partition with uuid=7f95820f-5e33-4e6c-8f50-0760bf06d79cand set the partition as root if found.

Example 2:

uuid ()

which will print the uuid of the current root device.

******************************************************************************

*** gfxmenu support in grub4dos *********************************************************************************

Gfxmenu support has been added to grub4dos. To use it, you must first find themessage file you need, then load it in menu.lst with command like this:

gfxmenu /message

This should be a gloabl command, that is, not inside any menu item. Also, itcan only be used in configure file, running it in console mode does not work.

gfxmenu does not work in conjunction with the password feature.

There are two major format of message file. Old format is created with gfxboot3.2.* or older (size of message file is normally about 150K), while new formatis created with gfxboot 3.3.* and later (size of message file is normally above300K). Both format are supported in grub4dos.

********************************************************************************* Use 'write' to write a string into a device or file *********************************************************************************

Usage:

write [--offset=SKIP] ADDR_OR_FILE INTEGER_OR_STRING

SKIP is an integer and defaults to 0.

If ADDR_OR_FILE is an integer, then it is treated as a memory address, andINTEGER_OR_STRING must be an integer value. The integer INTEGER_OR_STRINGwill be written to address (ADDR_OR_FILE + SKIP).

If ADDR_OR_FILE is a device or a file, then INTEGER_OR_STRING is treated asa string which will be written to ADDR_OR_FILE at offset SKIP (in bytes).

The string is quoted with nothing, that is, neither with the single quotechar(') nor with the double quote char(").

Space char must be quoted with back slash(\). (Update: need not now)

Single quote char(') and double quote char(") are not interpreted speciallyand can be used directly in the string.

Some C-style quote sequences are interpreted as follows:

\NNN character with octal value NNN (1 to 3 digits)

\\ backslash

\a alert (BEL)

\b backspace

\f form feed

\n new line

\r carriage return

\t horizontal tab

\v vertical tab

\xHH byte with hexadecimal value HH (1 to 2 digits)

Just like dd, the write can neither enlarge nor reduce the size of thedestination file, the leftover tail of the string will be discarded.The destination file cannot be a gzipped file.

Again like dd, the write command is also dangerous, use at your own risk.And to be on the safe side, you should only write to memory files.

In some cases when writing a file in a NTFS volume, the write might fail.

If you attempt to write a device or a block file that is not in memory byusing write in a menu, you will safely be refused :-) (Update: no restrictionsnow)

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~!!!!!!!! Caution! The file to write can be a device name which stands !!!!!!!! for all the sectors on the device. Take utmost care! !!!!!!!!______________________________________________________________________!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

********************************************************************************* Item-by-item help text for menu entries *********************************************************************************

The help message at the bottom of the screen will vary as you choose the menu.

You may append your help text to the title line. The help text must beginwith "\n", for example:

title This is the title\nThis is the help text.\nAnd this is the 2nd line of the help text.

Some C-style quote sequences are interpreted as stated in the section above.

********************************************************************************* initrd can load multiple cpio files for Linux 2.6 kernels *********************************************************************************

Usage:

initrd FILE [FILE ...]

Note 1: You should not load more than one oldstyle disk images in this way,because this is not supported by Linux kernel.

Note 2: The FILEs should be specified in the same order as with syslinux.

********************************************************************************* access some internel variables at a fixed location *********************************************************************************

Address Length Description========= ======== ==============================================0000:8208 4 (DWORD) install_partition (the boot partition)0000:8280 4 (DWORD) boot_drive (the boot drive)0000:8284 4 (DWORD) pxe_yip (your ip)0000:8288 4 (DWORD) pxe_sip (server ip)0000:828C 4 (DWORD) pxe_gip (gateway ip)0000:8290 8 (QWORD) filesize (file size by last "cat --length=0")0000:8298 4 (DWORD) saved_mem_upper (extended memory size in KB)0000:829C 4 (DWORD) saved_partition (current root partition)0000:82A0 4 (DWORD) saved_drive (current root drive)0000:82A4 4 (DWORD) no_decompression (no auto gunzip)0000:82A8 8 (QWORD) part_start (start sector of last partition)0000:82B0 8 (QWORD) part_length (total sectors of last partition)

Note 1: Filesize can be initialised/modified by using "cat --length=0 FILE".Note 2: You should not write these variables by hand(should read only).Note 3: You may use 1K at 6000:0000 for your own varibles(See note 4).Note 4: The read command now returns the integer value at the given address.Note 5: Grub4dos does not have the variable expansion feature. You can only

use integer variables. You need not declare them, but use the memoryaddress directly. Usually you want to use variables as a logicalvalue or in a command for conditional test, e.g., of this form:

"checkrange RANGE read ADDR"Note 6: no_decompression, saved_drive and saved_partition are writable.

********************************************************************************* possibility to run another menu.lst after gfxmenu *********************************************************************************

Notice the use of CONFIGFILE after GFXMENU in the following example:

# The menu.lst file for gfxmenudefault=0timeout=5gfxmenu /messageconfigfile /another.lsttitle 0..........................title 1..........................title 2..........................# End of menu.lst

# Begin another.lstdefault=0timeout=5title 0..........................title 1..........................title 2..........................# End of another.lst

This will try gfxmenu command first. On exit(or on failure) control will goto another.lst file.

********************************************************************************* a range of drives can be unmapped *********************************************************************************

Usage:

map --unmap=RANGE

RANGE is a range of BIOS drive numbers to be unmapped. BIOS drive number 0is for the first floppy, 1 is for the second floppy; 0x80 is for the firsthard drive, 0x81 is for the second hard drive, etc; virtual cdrom (hd32)corresponds to BIOS drive number 0xA0, (hd33) corresponds to 0xA1, etc.

For description on RANGE, please refer to section `The New Command CHECKRANGE'above.

Example 1:

map --unmap=0,0x80,0xff

This will unmap virtual floppy (fd0), virtual hard drive (hd0) and virtualcdrom (0xff).

Example 2:

map --unmap=0:0xff

This will unmap all virtual floppies, all virtual hard drives and all virtualcdroms.

Note 1: Normally a `map' command will add an item in the drive map table fora virtual drive. But `--unmap' means items in the drive map table(for the specified virtual drives) will be deleted.

Note 2: The --unhook option only breaks the INT13 hook(to the inerruptvector table). It will not affect the drive map table. And later onexecution of a `boot' command, the INT13 disk emulation routine willautomatically get hooked(to the interrupt vector table) when needed(e.g., the drive map table is non-empty) even if it has been unhooked.

Note 3: Usually you want to do a `map --rehook' after you have changed thedrive map table.

********************************************************************************* geometry tune and sync *********************************************************************************

When a USB storage device is connected to a (or another) machine, the geometryin the partition table or in the BPB of the volume could be invalid, and themachine could hang at boot time. So you need to find out the correct geometryfor the drive (use `geometry --tune'), and then update the geometry inpartition table and BPB of the drive(use `geometry --sync').

The above steps are required if you are going to boot DOS, because DOSrequires the right geometry in the partition table and BPB. Windows/Linux mayalso require it, since the boot process could run in real-mode.

******************************************************************************

*** Version numbering *********************************************************************************

Now we append a letter 'a', 'b', 'c' or 'p' to the version number(e.g., 0.4.5).So the version will become 0.4.5a, 0.4.5b, 0.4.5c, 0.4.5 or 0.4.5p.

'a' - alpha test. unstable, especially when there are known bugs.'b' - beta test. the developers think it has no bugs and want a widely testing.'c' - release candidate.''(nothing) - official release.'p' - patched versions to the official release.

********************************************************************************* Running User Programs *********************************************************************************

From 0.4.5 on, user programs can be developed for running under grub4dos. Theexecutable program file must end with the 8-byte grub4dos EXEC signature:

0x05, 0x18, 0x05, 0x03, 0xBA, 0xA7, 0xBA, 0xBC

The executable must have no relocations, and the entry point is at the verybeginning of the file, just like a DOS .com file(but the grub4dos executableis 32-bit).

Here is a sample file echo.c:

/*================ begin echo.c ================*/

/* * compile:

gcc -Wl,--build-id=none -m32 -mno-sse -nostdlib -fno-zero-initialized-in-bss -fno-function-cse -fno-jump-tables -Wl,-N -fPIE echo.c -o echo.o

* disassemble: objdump -d echo.o * confirm no relocation: readelf -r echo.o * generate executable: objcopy -O binary echo.o echo * * and then the resultant echo will be grub4dos executable. */

/* * This is a simple ECHO command, running under grub4dos. */

int i = 0x66666666; /* this is needed, see the following comment. */

/* gcc treat the following as data only if a global initialization like the * above line occurs. */

/* a valid executable file for grub4dos must end with these 8 bytes */asm(".long 0x03051805");asm(".long 0xBCBAA7BA");/* thank goodness gcc will place the above 8 bytes at the end of the b.out * file. Do not insert any other asm lines here. */

intmain(){ void *p = &main;

return/* the following line is calling the grub_sprintf function. */((int (*)(char *, const char *, ...))((*(int **)0x8300)[0]))/* the following line includes arguments passed to grub_sprintf. */

(0, p - (*(int *)(p - 8)));}

/*================ end echo.c ================*/

0x8300 is a pointer to the grub4dos system funtions(API). The system_functionsvariable is defined in asm.S.

More function can use in user programs:http://grubutils.googlecode.com/svn/trunk/src/include/grub4dos.h

note: After 2010-11-16 version of grub4dos,you can use like below./////////////////echo.c start///////////////////////////////////////////////#define sprintf ((int (*)(char *, const char *, ...))((*(int **)0x8300)[0]))

#define printf(...) sprintf(NULL, __VA_ARGS__)int i = 0x66666666;asm(".long 0x03051805");asm(".long 0xBCBAA7BA");int main(char *arg,int flags){

return printf("%s\n",arg);}/////////////////echo.c end/////////////////////////////////////////////////

********************************************************************************* Map options added by Karyonix *********************************************************************************

(from boot-land.net) Karyonix's note:

map --add-mbt= option to be used with --mem. If =0 master boot track will notbe added automatically.

map --top option to be used with --mem. map --mem will try to allocate memoryat highest available address.

map --mem-max=, map --mem-min options to be used before map --mem. Allow userto manually limit range of address that map --mem can use.

safe_parse_maxint_with_suffix function parses K,M,G,T suffix after number.

********************************************************************************* Graphics mode 6A: 800x600 with 16 colors *********************************************************************************

Graphics mode now has 2 possibilities, one is the default 640x480 mode, and theother is 800x600 mode.

To enter 800x600 mode, follow this way:

1. Be sure you are in console text mode. You may execute "terminal console".

2. Set graphics mode to 0x6A by using command "graphicsmode 0x6A".3. Enter graphics mode. You may execute command "terminal graphics".

To return to 640x480 mode, follow this way:

1. Be sure you are in console text mode. You may execute "terminal console".2. Set graphics mode to 0x12 by using command: "graphicsmode 0x12".3. Enter graphics mode. You may execute command "terminal graphics".

****************************************************************************** ***** GRUB4DOS variable support ***********************************************************************************

From now we supports variables, the same usage of MSDOS.

commands: set [/p] [/a|/A] [/l|/u] [VARIABLE=[STRING]]variable specifies the variable name (up to 8 characters). string Specifies a string assigned to the variable (up to 512 characters

.)

SET command without parameters will display the current variables.

with "=",if the string is empty.set myvar=

Will delete the variable myvar

Show the name has been used for all variable. For example: set ex_

Will display all variables beginning with ex_, returns 0 if no match.

Note: 1. the same of MSDOS. a full line of command will be conducted before the implementation of

variable substitution. 2. Variable names must beginning with letter or "_". Otherwise you will not be able to access your variables.3. See the previous description for length limit. 3. To reset all used variable enter command "set *"

the new command ifif [/I] [NOT] STRING1==STRING2 [COMMAND]if [NOT] exist VARIABLE|FILENAME [COMMAND]

STRING1==STRING2 Specifies a true condition if the specified text strings match.COMMAND Specifies the command to carry out if the condition is met./I if specified, says to do case insensitive string compares.NOT Specifies that should carry out the command only if the condition is

false.

Example: 1. To determine whether strings are equal, and not case sensitive.

if /i test==%myvar% echo this is a test2. To determine the character is empty.

if %myvar%#==# echo variable myvar not defined.Usage example:

1. Displays a string including the variable.

echo myvar=%myvar% 2. Using a variable instead of command.

set print = echo %print% This a test.

3. You can use a "^" to stop extended, example echo %myvar^%

Or echo %my^var%

Will be displayed %myvar% rather than the extended character after myvar. Note: We only deal the ^ between the symbols %%.

****************************************************************************** ***** GRUB4DOS batch scripting support ***** ******************************************************************************

The new version supports running a batch script,It very like MS-DOS batch.Yes!you needn't to learn a new language.

Example of a simple script: ========= GRUB4DOS BATCH SCRIPT START =============================== !BAT #Note: The file header !BAT is necessary to identify this is a batc

hecho %0 echo Your type:%1 %2 %3 %4 %5 %6 %7 %8 %9 call :Label1 This is a test string goto :label2 :Label1 echo %1 %2 %3 %4 %5 %6 %7 %8 %9 goto :eof :Label2 echo end of batch script. ========= GRUB4DOS BATCH SCRIPT END ===============================

Some differences: 1. Batch will stop when an error occurs. 2. Use command "exit 1",if you need to stop a running batch script.3. %9 refers to all the remaining parameters. 5. extensions

%~d0 expands %0 to a drive letter.e.g: (hd0,0) ,()%~p0 expands %0 to a path only%~n0 expands %0 to a file name only%~x0 expands %0 to a file extension only%~f0 expands %0 to a fully qualified path name%~z0 expands %0 to size of file

6.You can find some script in below site. http://chenall.net/post/tag/grub4dos/

********************************************************************************Conditional Menu(iftitle)

********************************************************************************Conditional menu are support since 2011-12-04, it can determine to display a menu item by specified condition.For distinguishing from normal menu item, it uses new keyword "iftitle".

commands:iftitle [<command>] Actual Title displayed\nOptional help line

Note:1.command must be a valid GRUB4DOS command, it supports calling external

commands.Note: commands like eecho/pause are disabled in conditional menu. Almost all commands are useable, and you may report bug if you encou

nter unusable commands.2.a space before menu title is necessary.3.[] is necessary.4.If it is empty inside [], it acts same as title command.5.You can use this function to comment out a menu item by putting invali

d command inside [].

readme grub4dos

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