On Sun, 23 Feb 2025 at 11:47, Bernhard Beschow <shen...@gmail.com> wrote: > > On a real device, the boot ROM contains the very first instructions the CPU > executes. Also, U-Boot calls into the ROM to determine the boot device. While > we're not actually implementing this here, let's create the infrastructure and > add a dummy ROM with all zeros. This allows for implementing a ROM later > without > touching the source code and even allows for users to provide their own ROMs. > > The imx8mp-boot.rom was created with > `dd if=/dev/zero of=imx8mp-boot.rom bs=1 count=258048`. > > Signed-off-by: Bernhard Beschow <shen...@gmail.com>
Hi; I've thought about this a bit, and I think we should just postpone having code to load a rom blob until we have an actual rom blob that's not all zeroes. This makes this board the same as e.g. imx7 which also doesn't try to load a ROM blob. You can create a memory region for the ROM, like imx7; just don't load anything into it, and that's exactly the same as if there was an all-zeroes file that got loaded. This doesn't prevent users from experimenting with providing their own ROM code, because they can do that with the generic loader (passing it either an ELF file set up to load to the ROM area or else a binary blob plus the start address of 0). That way we aren't carrying code we aren't using and an awkward binary blob in git; we can add those when we need them. thanks -- PMM
