imx91: mmc write offset to user partition

[stoejs]

Hi there,
I'm trying to find the correct offset to write flash.bin into the user partition
via mmc. My lst file, the write command is in the second to last line:

uuu_version 1.2.39

SDPS: boot -f ./flash.bin

SDPV: delay 1000
SDPV: write -f ./flash.bin -skipspl
SDPV: jump

FB: ucmd env set fastboot_buffer 0x80000000
FB: ucmd mmc erase 0x0 0x2000
FB: download -f ./flash.bin
FB: ucmd setexpr filesize $filesize + 0x1ff
FB: ucmd setexpr sectors $filesize / 0x200
FB: ucmd mmc write 0x80000000 64 $sectors
FB: Done

There is a emmc memory map in IMX91RM (9.8.2.4), which states that there are several unused areas.
I tried several offsets, e.g. 0x8000 == 32 kB resolving with block size 512 kB to 64.
Is this the right way?

I know about uuu's -b emmc, but I want to write the binary to the user partition
as the environment needs to be able to be changed from userland later.

Any help is appreciated.

[kawateb265 · Accepted solution]

You can refer to the following link for a demo on the user partition of the iMX secondary boot, which shows how to write the image to different offsets.

https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/iMX-secondary-boot-collection/ta-p/19169...

[stoejs]

Thank you. 0x40 is the offset I was looking for.