[U-Boot] eMMC boot partition support in uboot

[Richard Retanubun <richardretanubun@ruggedcom.com>]

On 05/12/13 02:09 PM, Tom Rini wrote:
> On Thu, Dec 05, 2013 at 01:46:40PM -0500, Richard Retanubun wrote:
>
>> Hi guys,
>>
>> Recap: I am trying to boot MLO + uboot from eMMC boot partition on DRA7xx_EVM eval platform.
>> SW-Baseline: uboot p-ti-uboot-2013.04 & p-ti-linux-3.8.y from omapzoom.
>
> Please note that this list is for the mainline U-Boot tree, and not to
> contact your TI reps for help with the TI trees.  I'm answering in
> general since I know how the mainline code works, and what I suspect
> needs doing there in general to allow what you want to work:

Sorry if I appear as abusing the mailing list. That was not the intent
and I will stop doing it for this issue.

The main reason I am including the mailing list is to share notes on what
had to be done even to get the MLO loaded and booting in alternate boot mode.

I realize my problem may be ti tree specific, but I think the EXT_CSD settings
in the eMMC I found is of value on many other CPUs booting over eMMC.

> [snip]
>> 3. I realize that the MLO contents (using uboot/tools/omapimage?) needed to say
>>     MMCSD_MODE_RAW for my platform. I am bypassing this problem by by hard coding the response
>>     arch/arm/cpu/armv7/omap-common/boot-common.c::spl_boot_mode() to always says MMCSD_MODE_RAW.
>>     This seems to work and I am past the hang() code.
>
> It's possible that the ROM simply doesn't support a dos-style partition
> table and a FAT partition on the eMMC boot partition so the right answer
> here is to do what you're doing and hard-code raw only.  I strongly
> suspect this to be true, even.
>
>> 4. Now, MLO is ready to (raw) load uboot binary from the eMMC boot partition (i.e. /dev/mmcblk1boot0).
>>     Unfortunately, at this point I don't know how to make the platform recognize the eMMC boot partitions.
>>     I think they are not modelled yet in uboot. Only the User-Data-Area (UDA)
>>     is recognized in uboot (called mmc 1)
>
> Not quite true, no.  You'll need code similar to what we have in
> common/env_mmc.c to switch the partition to the boot partition.
>
I'll have a look at that then, Tom. Thank you for your time.