History•8xxROM by Magnus Damm•PPCBoot (1999) – v 0.4.1 (2000)•U−Boot−0.1.0 (2002)extended functionality, new architectures

•Das U-Boot

What is Das U-Boot•Universal Bootloader•MIPS, NIOS, ARM, PowerPC...

allows:•bring-up•development•debugging•finished system boot-loader

Why Das U-Boot•serial console support•integrated shell-like setup interface•optional password protection and timeout for access to

setup interface on boot•editable configuration space•capable of booting through TFTP, SCSI, IDE etc.•range of file systems supported•runs test applications directly•boots Linux

How it works$ git clone git://git.denx.de/u-boot.git

for igepv2:$ wget http://downloads.igep.es/sources/u-boot-arm-2010.06-3.tar.gz

$ make gta01_config$ make CROSS_COMPILE=arm-none-linux-gnueabi- <board-config> (igep0020_config)

$ make ARCH=arm CROSS_COMPILE=arm-angstrom-linux-gnueabi- u-boot.udfu$ make CROSS_COMPILE=arm-none-linux-gnueabi-

How it worksu-boot.map - The symbol mapu-boot - U-Boot executable in ELF binary formatu-boot.bin - U-Boot raw binary image, which can be written to

the boot storage deviceu-boot.udfu - U-Boot image in the special U-Boot Device

Firmware Upgrade (DFU) file format used by the OpenMoko devices

How it worksU-Boot 1.3.2-rc2-dirty-moko12 (Mar 30 2008 - 23:40:43)I2C: readyDRAM: 128 MBNAND: 64 MiBFound Environment offset in OOB..Video: 640x480x8 31kHz 59HzNAND read: device 0 offset 0x25c000, size 0x5000Reading data from 0x260e00 -- 100% complete.20480 bytes read: OKUSB: S3C2410 USB DevicedIn: serialOut: serialErr: serial

GTA01Bv4 #

How it worksGTA01Bv4 #

GTA01Bv4 # help? - alias for 'help'askenv - get environment variables from stdinautoscr - run script from memorybase - print or set address offsetbdinfo - print Board Info structurebmp - manipulate BMP image databoot - boot default, i.e., run 'bootcmd'

Why not... GRUB?•No “monitor” capabilities•Requires x86-based host•Makefiles not built for cross-compilation

Hot off the press... added last night!

More Info on Das U-Boot•Building Embedded Linux Systems,

Karim Yaghmour, Jon Masters, Gilad Ben-Yossef and Philippe Gerum

•Documentation on the web (14 chapters):http://www.denx.de/wiki/U-Boot/WebHome