Hi Peter,

Update below.

On Mon, Nov 8, 2021 at 4:14 PM Peter Bergin <peter@berginkonsult.se> wrote:
Hi Brian,

On 2021-11-08 13:55, Brian Hutchinson wrote:
> It does not.  It shows no signs of a problem, returns no errors or
> warnings at all.  It "looks" like it worked normal but does not change
> the u-boot environment variable.
>
libubootenv in hardknott seems to be 0.3.1. Looked in the libubootenv
repo and found this commit that is added after which indicates that it
could be silent failure of fw_setenv.
https://github.com/sbabic/libubootenv/commit/42f919e29c7b5e86a25877a9c492017e62f8827c
I don't have a clue if this helps but just to help you with ideas one
thing could be to test this and see if the function libuboot_set_env
returns error code or not.

Can you write to the memory with some other application than fw_setenv?
 
No.  Apparently not.  I've compared kernel .config and device tree source from 5.4 series kernel and 5.10 series kernel and I cannot find an explanation for this but the following test fails:

root@imx8mmevk:~# flashcp -v ./imx8mm-evk.dtb /dev/mtd7                                                                                                                                                                                                          
Erasing blocks: 11/11 (100%)
Writing data: 40k/40k (100%)
Verifying data: 10k/40k (24%)File does not seem to match flash data. First mismatch at 0x00000000-0x00002800

I simply tried writing a file to an area of my NOR that I didn't care if it got overwritten.  So it does look like there is a problem with kernel flexspi driver or mtd drivers?

Regards,

Brian