Skip to content
hno edited this page Sep 20, 2012 · 42 revisions

u-boot for Allwinner A10

Branch information:

sunxi Default branch. Most up to date and supports both A10 and A13.

sun4i Old A10 branch. No longer maintained.

sun5i Old A13 branch. No longer maintained.

lichee/ Unmodified mirrors of original Allwinner sources

wip/ Work in progress temporary feature branches.

Tags/Releases

v2011.09-sun4i

How to compile u-boot

You need a suitable gcc ARM Linux GNUEABI toolchain installed and added to your PATH.

Then compile u-boot by running

make sun4i CROSS_COMPILE=arm-none-linux-gnueabi-

or alternatively depending on how your toolchain is configured

make sun4i CROSS_COMPILE=arm-linux-gnueabi-

How to make a bootable sunxi SD-card

A10 boots the SPL loader from block 8. This then loads actual u-boot from block 32 onwards, counted in 1KB blocks.

dd if=spl/sun4i-spl.bin of=/dev/sdc bs=1024 seek=8
dd if=u-boot.bin of=/dev/sdc bs=1024 seek=32

You also need to partition the card to store system.bin, uImage, boot.scr (optional) and rootfs partition there. First partition should start at sector 2048 to leave sufficient space for uboot & environment.

uEnv.txt support

This version of u-boot support uEnv.txt, and will look for it in the first partition FAT /uEnv.txt or extX /uEnv.txt or extX /boot/uEnv.txt. uEnv.txt contains variables on the form variable=value, one per line. If the variable uenvcmd is set then u-boot will run the commands listed in this variable.

boot.scr support

This version of u-boot supports boot.scr, and will look for it in the first partition FAT /boot.scr or extX /boot.scr or extX /boot/boot.scr. boot.scr contains your needed uboot commands for loading script.bin, kernel. initrd (optional), setting kernel parameters and booting.

To create boot.scr first make a u-boot script boot.cmd with the u-boot commands you need for booting your system. An example follows:

setenv bootargs console=ttyS0 root=/dev/mmcblk0p1 rootwait panic=10 ${extra}
ext2load mmc 0 0x43000000 boot/script.bin
ext2load mmc 0 0x48000000 boot/uImage
bootm 0x48000000

Then translate this to a boot.scr by using the mkimage command

mkimage -C none -A arm -T script -d boot.cmd boot.scr

Default boot action

If no boot.scr is found then it will fall back to load script.bin & kernel uImage from the first partition in FAT format

fatload mmc 0 0x43000000 script.bin && fatload mmc 0 0x48000000 ${kernel} && watchdog 0 && bootm 0x48000000

Watchdog support

wip/watchdog branch of u-boot has built-in watchdog support. Be warned that If the kernel is not up and running within the watchdog timeout (approximately 20 seconds) then the watchdog will automatically reboot.

If your OS do not support watchdog then you need to disable the watchdog before booting the kernel by adding

watchdog 0

to your boot.scr script.

Default environment

baudrate=115200
scriptaddr=0x44000000
bootscr=boot.scr
bootenv=uEnv.txt
loadbootscr=fatload mmc 0 ${scriptaddr} ${bootscr} || ext2load mmc 0 ${scriptaddr} ${bootscr} || ext2load mmc 0 ${scriptaddr} boot/${bootscr}
loadbootscr=fatload mmc 0 ${scriptaddr} ${bootenv} || ext2load mmc 0 ${scriptaddr} ${bootenv} || ext2load mmc 0 ${scriptaddr} boot/${bootenv}
boot_mmc=fatload mmc 0 0x43000000 script.bin && fatload mmc 0 0x48000000 ${kernel} && watchdog 0 && bootm 0x48000000
bootcmd=if run loadbootenv; then \
                echo Loaded environment from ${bootenv}; \
                env import -t ${scriptaddr} ${filesize}; \
        fi; \
        if test -n ${uenvcmd}; then \
                echo Running uenvcmd ...; \
                run uenvcmd; \
        fi; \
        if run loadbootscr; then \
                echo Jumping to ${bootscr}; \
                source ${scriptaddr}; \
        fi; \
        run setargs boot_mmc;"
bootdelay=3                                                                           
console=ttyS0,115200                                                                  
kernel=uImage                                                                         
loglevel=8                                                                            
panicarg=panic=10                                                                     
root=/dev/mmcblk0p2
setargs=setenv bootargs console=${console} root=${root} loglevel=${loglevel} ${panicarg} ${extraargs}
stderr=serial                                                                         
stdin=serial                                                                          
stdout=serial 

Storage map

How the SD-Card is used by u-boot-mmc, counted in 1KB blocks:

start size
  0   8KB Unused, available for partition table etc.
  8  24KB Initial SPL loader
 32 512KB u-boot
544 128KB environment
672 352KB reserved
1024    - Free for partitions
Clone this wiki locally