U-Boot + usage and documentation by Ulf Samuelsson. +
+ +$LastChangedDate: 2008-12-16 10:00:11 +0100 (tis, 16 dec 2008) $
+-
+
- About U-Boot +
- Board Support for AT91RM9200DK +
- Board Support for AT91RM9200EK +
- Board Support for AT91SAM9G20EK +
- X-Modem/Raw extensions to minicom +
- New Command: factory +
- New Command: os +
- New Command: fs +
- New Command: setargs +
- New Command: led +
- New Command: mux +
- New Command: ethinit +
- Special environment variables +
About U-boot
+ [TOP] + ++ U-Boot is an open source bootloader ported to a multitude of processors. + See (U-Boot Home) + for documentation for vanilla U-Boot. This document only describes + changes compared to the vanilla u-boot. +
+ +Board support for at91rm9200dk
+ [TOP] + ++ "at91rm9200dk" is updated to use a linux like API for gpio. + A new target "at91rm9200dk_df" is defined to support boot from dataflash. +
+ +Board support for at91rm9200ek
+ [TOP] + ++ The "at91rm9200ek" BSP supports booting from a parallel flash. + The "at91rm9200df" BSP supports a generic target booting from dataflash. +
+ +Board support for at91sam9g20ek
+ [TOP] + ++ The "at91sam9g20ek" target with dataflash(card) and NAND boot support. +
+ +Minicom extensions
+ [TOP] + ++ "sx-at91" is a reliable X-Modem application allowing download to the at91rm9200 + based board +
++ "raw-at91" is a download application which will download binary data using minicom. + Typically used to download an environment script. +
+ +New command: factory
+ [TOP] + ++
factory
+
+
+ + "factory" will set a selected set of environment variables + back to the compile time default. The following will give some + hints on capabilities, but is not yet complete. +
+ ++ It will generate a set of scripts which will facilitate downloading + the kernel and root file system using tftp and will also + add commands to store into and retrieve from flash +
+ +New command: os
+ [TOP] + ++
os
+
+ + "os" computes a new name for the linux kernel +
+ +New command: fs
+ [TOP] + ++
fs
+
+ + "fs" computes a new name for the file system +
+ +New command: setargs
+ [TOP] ++
setargs
+
+ + "setargs" will create new bootcmd/bootargs combination from + kernel name, filesystem name, and rootfs type. +
+ +New command: led
+ [TOP] + ++
led [green | yellow | red | all ] [ on | off ]
+
+
+ + "led" will turn on or off the specified (coloured) led +
+ +New command: mux
+ [TOP] + ++
mux [spi | mmc ]
+
+
+ + "mux" will select how to use the flash card connector on the + at91rm9200dk or at91rm9200ek +
+ +New command: ethinit
+ [TOP] + ++
ethinit
+
+
+ + "ethinit" can be used to delay the boot of linux, until a valid network + connection has been established. This is useful if the machine is NFS mounting + the root file system and both this machine and the NFS server are powering up + simultaneously. The NFS server could take a lot longer to boot, and waiting + for this to boot may be neccessary for proper operation. +
+ +Special environment variables
+ [TOP] + ++
rd
+
+
+ rd contains the name of the current root file system
+ It is autmatically generated from
+
ver
+
+
+ You can handle a number of different root fs by defining ver.
+ When running fs rd will be assigned from one of:
+
rd-1, rd2, rd-3 ...
+ By defining ver to a number you will
+ select the appropriate disk name
+
+
fs-date
+
+ + "date" part of the root file system name +
+ ++
linux
+
+ + linux contains the name of the current kernel. +
+
+ It is generated from several environment variables when os is run
+
+ A typical name would be "at91sam9263ek-linux-2.6.28-20090105.gz" +
+ ++
hostname
+
+ + "name" part of the kernel file name +
+ ++
kernel-version
+
+ + "version" part of the kernel file name +
+ ++
kernel-date
+
+ + "date" part of the kernel file name +
+ ++
fstype [ ram | flash ]
+ + You can have several file system types. + bootargs is created depending on fstype.. +
+ + [TOP] + +