For context, I'm trying to make everything in flash as fault-tolerant as possible. Ideally, I'd like to just store the kernel image and initrd file as just BLOBs on MMC.
So as I understand, U-Boot looks for an extlinux.conf or boot.scr file, but as I said I'd rather not rely on the filesystem tables at all.
Would it be safe to just do everything in the main_loop function by just calling mmc read... to load in the kernel image, followed by the boot command? Do I need to do something with the initrd file too?
In short, yes, you would partition your MMC device such that you use mmc read ... to bring in the kernel, device tree, and if used by your system, initrd in to DDR and then use bootm to start the system. You'll also want to have the partition table on your device mark the area where you have the kernel, etc, as reserved in some manner.