Re: [PATCH v1 0/2] fastboot: mmc: fix bootloader offset

Heiko Schocher
2026-01-26T15:46:25Z

Hello Mattijs,

On 26.01.26 10:48, Mattijs Korpershoek wrote:
> Hi Heiko,
>
> Thank you for the patch.

You are welcome!

>
> On Sat, Jan 24, 2026 at 06:47, Heiko Schocher <hs@nabladev.com> wrote:
>
>> Not for all SoCs the bootloader start at offset 0x0,
>> in a hardware partition of an emmc. So we need the possibility to
>> set the correct offset, where bootloader starts.
>>
>> Example:
>>
>> imx8qxp revision C0 emmc Partition layout
>>
>> | eMMC block / partition | Offset | Size | Purpose |
>> | ---------------------- | ---------- | ----- | ------------------------------ |
>> | /dev/mmcblk0boot0 | 0x0 | 2MB | imx-boot-container A |
>> | | 0x00220000 | 128kB | secure boot signature rootfs A |
>> | /dev/mmcblk0boot1 | 0x0 | 2MB | imx-boot-container B |
>> | | 0x00200000 | 8kB | U-Boot env 0 |
>> | | 0x00202000 | 8kB | U-Boot env 1 |
>> | | 0x00220000 | 128kB | secure boot signature rootfs B |
>>
>> imx8qxp rev B0 emmc Partition layout
>>
>> | eMMC block / partition | Offset | Size | Purpose |
>> | ---------------------- | ---------- | ----- | ------------------------------ |
>> | /dev/mmcblk0boot0 | 0x00008000 | 2MB | imx-boot-container A |
>> | | 0x00220000 | 128kB | secure boot signature rootfs A |
>> | /dev/mmcblk0boot1 | 0x0 | 8kB | U-Boot env 0 |
>> | | 0x00002000 | 8kB | U-Boot env 1 |
>> | | 0x00008000 | 2MB | imx-boot-container B |
>>
>
> Why can't we use raw partition descriptors for this?
>
> See:
> https://docs.u-boot.org/en/latest/android/fastboot.html#raw-partition-descriptors

Thanks for this hint!

Possible yes ( I must try)... but this will lead in adding
complexity to scripts people use all over there and needs
to adapt CI setups, as siemens has B0 and C0 variants.

If we introduce this series, user has nothing to know about
offsets for different CPU modules as no change in API for
them...

bye,
Heiko
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