firmware file seen during boot differs from the file that I put after boot

[wwortel]

Built an Edge/Jammy  firmware for a rk3588s2 based system(Radxa CM5). Panthor firmware for GPU G610 is not the right version though  in this image.

So after boot changed the firmware file, in the /lib/firmware/arm/mali/arch10.8/ folder, to the right version.

Reboot produces the same problem though. It does not see the modified file, but still the original, wrong,  one.

With boot complete and going to the firmware folder the changed firmware is there.

I presume that the changes I make end up in an overlay that only is mounted after the boot process.

Rewriting the whole 6 GB image, just to change one file, is a bit cumbersome. Is there a way to change the underlying file so that it is used during boot?