[Arm-netbook] EOMA68-A20: boot from microsd (SD3)

[luke.leighton]

On Wed, Aug 14, 2013 at 8:52 AM, Henrik Nordström
<henrik at henriknordstrom.net> wrote:
> mån 2013-08-12 klockan 16:08 +0100 skrev luke.leighton:
>
>> what's needed to prep a boot image that will by default boot off of
>> SD3 instead of SD0?
>> we'd like to be sending out CPU Cards that will look for even u-boot on SD3.
>
> Good question if that can be done with livesuit.

 euuw, euuw :)

> But you can get very close. You can build u-boot with MMC support and
> chain-loading u-boot from SD3

 ok.  ahh yes, i think i have this (or close to it).

> boot0 (NAND boot) -> boot1 (NAND boot) -> boot.axf (nanda) -> u-boot.bin
> (nanda) -> u-boot.bin (raw SD3).

 ok so that's leaving the allwinner bootloader on there, and just
modifying the boot params, right?

> Personally I would settle for u-boot loaded from nand and looking for
> uEnv.txt / script.bin in SD3. Those that absolutely want to load their
> own u-boot can do that from there. Just make sure to set a unique
> variable in the nand u-boot default environment so uEnv.txt / script.bin
> can check which version of u-boot are running.
>
> But yes, it is in theory possible to prepare a livesuit image with an
> SD3 u-boot SPL. But u-boot SPL and livesuit is not entirely compatible
> at the moment so some work is needed.
>
> It should also be possible to hack up a custom boot0 that will look for
> SD3 instead of whatever Livesuit recorded in the boot header, but might
> be easier to massage u-boot SPL for the purpose.
>
> It is also possible to write u-boot SD3 SPL directly to the NAND boot
> area, but procedure for writing to the NAND boot area is still a bit
> shaky.

 ah joy.