imx91: mmc write offset to user partition

stoejs — Thu, 16 Oct 2025 07:15:55 GMT

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.

Re: imx91: mmc write offset to user partition

kawateb265 — Fri, 17 Oct 2025 23:55:06 GMT

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/1916915

Re: imx91: mmc write offset to user partition

stoejs — Mon, 20 Oct 2025 06:52:42 GMT

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

topic imx91: mmc write offset to user partition in i.MX Processors

imx91: mmc write offset to user partition

Re: imx91: mmc write offset to user partition

Re: imx91: mmc write offset to user partition