Talk:Kernel-with-device-tree

From ArmadeusWiki
Revision as of 16:05, 23 September 2013 by JulienB (Talk | contribs) (→‎Old U-Boot)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

Old U-Boot

To enable device tree on old U-Boot, it's quite simple:

  • add "#define CONFIG_OF_LIBFDT" in the u-boot configuration file (include/configs/<board>.h).

On armadeus SDK, this file is in this directory: buildroot/target/device/armadeus/<board>/<board>-u-boot-<version>.h

For example, for u-boot 2012.04 on apf27, it's: buildroot/target/device/armadeus/apf27/apf27-u-boot-2012.04.h

Nothing else needs to be done, because the u-boot image is build by the armadeus SDK with the command "make".

NOTE: on u-boot 2012.04, the command bootm with device tree is broken. If you want to use it,

you need to fix it with the following patch: http://git.denx.de/?p=u-boot.git;a=commit;h=1723997610ace497252d6f9a44ec76c06951ae43

NOTE2: it's fixed on u-boot 2012.04.01 that's the current (since June 2012) release used on all the APF boards.

Kernel manual booting (deprecated)

Start the U-Boot previously compiled or use the latest U-Boot 2013.04, and then :

  • load the kernel in memory
  • load the dtb in memory
  • run the command bootm with 3 arguments: <kernel addr> - <dtb addr>

The second argument is "-", it means that there isn't an initrd to load.

For example, on APF27, it should be something like this: 

BIOS> setenv consoledev ttymxc0
BIOS> setenv baudrate 115200
BIOS> setenv dtbaddr 0xa0800000
BIOS> tftp $loadaddr apf27-linux.bin
BIOS> tftp $dtbaddr imx27-apf27.dtb
BIOS> setenv consoledev ttymxc0
BIOS> setenv console console=$consoledev,115200
BIOS> setenv bootargs ${console} earlyprintk
BIOS> run addnfsargs addipargs
BIOS> bootm $loadaddr - $dtbaddr
Retrieved from "http://armadeus.org/wiki/index.php?title=Talk:Kernel-with-device-tree&oldid=12099"