[U-Boot] [PATCH] am335x_evm: Consolidate eMMC partitions with DFU info

[Sam Protsenko]

On 8 February 2018 at 20:26, Tom Rini <trini at konsulko.com> wrote:
> On Wed, Feb 07, 2018 at 08:41:32PM +0200, Sam Protsenko wrote:
>
>> From DFU_ALT_INFO_EMMC (include/environment/ti/dfu.h) we can see that
>> rootfs will be flashed to second partition on eMMC. But at the moment we
>> have only one partition in $partitions environment variable. Let's add
>> "bootloader" partition prior to "rootfs", so that DFU works correctly.
>> This also fixes eMMC boot, which looks for rootfs on second partition.
>>
>> "bootloader" partition start corresponds to "u-boot.img.raw" in DFU
>> eMMC info, which is 0x300 sector (384 KiB offset from eMMC start).
>>
>> rootfs start address can be also found from DFU eMMC info.
>> bootloader-related area is finished at 0x1500 sector (2688 KiB offset
>> from eMMC start). This should be the start address for rootfs in
>> $partitions environment variable.
>>
>> While at it, fix U-Boot environment address to be the same as for
>> AM57x EVM, so that it doesn't clash with other partitions.
>>
>> So now eMMC layout looks like this:
>>
>>     ===============================================================
>>
>>     0       +------------------------+
>>             | MBR/GPT header         |   128           -
>>     128     +------------------------+
>>             | MLO                    |   256           -
>>     384     +------------------------+
>>             | u-boot.img             |   1792          bootloader
>>     2176    +------------------------+
>>             | //////// hole //////// |   256           -
>>     2432    +------------------------+
>>             | U-Boot environment     |   128           -
>>     2560    +------------------------+
>>             | U-Boot environment     |   128           -
>>             | (redundant)            |
>>     2688    +------------------------+
>>             | rootfs                 |   remaining     rootfs
>>     end     +------------------------+
>>
>>     ===============================================================
>>
>> "hole" area can be used further for storing U-Boot environment (like
>> it's done in AM57x EVM config file) or for increasing u-boot.img area
>> (in case u-boot.img size increased, e.g. if new dtbs were added).
>>
>> This commit conforms with Linux partition table from f6d245b8c56c
>> ("arm: am57xx: Fix Linux boot from eMMC") commit, making things in
>> uniform way.
>>
>> Signed-off-by: Sam Protsenko <semen.protsenko at linaro.org>
>
> Reviewed-by: Tom Rini <trini at konsulko.com>
>

Hi Tom,

If there are no objections against this patch, can you please merge
it? We are working on BBB-based course, and I would love to see it in
v2018.03, so that students can checkout to that stable tag and have
all needed BBB support in upstream.

Thanks!

> --
> Tom