Linux Drivers

I'm compiling linux for this device but having trouble booting it. Everything I've come across so far points to a missing kernel driver for the card reader controller chipset. The closest .config option I've run across is CONFIG_EHCI_HCD_PLATFORM which directly references a cousin chipset from the manufacturer Genysis which manufactured the controller chipset for this board.

It is compiled with EFI stubs, all generic MMC, USB, and SD drivers. The kernel will boot into a panic VFS: unknown-block(0,0) when setting the efi unicode tag to 'root=/dev/sda3'. I'm trying to not use an initramfs.

Basically, I'm trying to use this guide without using PARTUUID https://wiki.gentoo.org/wiki/EFI_stub_kernel

Any thoughts?

Try Raspbian Stretch (debian for x86). I haven't had a single stutter from it while running from a USB 3.0 thumbdrive (with persistence). I figured, if they wanna call it the Atomic Pi then treat it like one. Those folks across the pond have done a pretty snazzy job of configuring this x86 version and I have to say, It's pretty snappy for a Pi.

I appreciate the suggestion, but that kernel option is slow and bulky. Since writing, I've finished configuring a 5.1.6 variant with some patches from clear linux and gentoo. The rt2870.bin firmware for the wifi chipset is inlined in the kernel and it only uses EFI stubs to boot. It's running well under some hardcore GCC 9.1 optimizations: past -O3, native options into LTO territory. I haven't tested sound or gpio functionality yet; however, this kernel is down to just 8MB. I'm planning on optimizing further away from an initrd and modprobe into a solitary bzImage with barebones modules included.

Update: for those wishing to try something similar, I suggest starting with the default image, creating a gentoo stage 3 chroot, copying over the kernel configuration from the atomic pi ubuntu image, and running make defoldconfig. It will create a bootable kernel under 5.1.6