Very slow kernel/initrd download (RPI + U-boot)

[mcb30]

(2019-10-02 19:39)ljfranklin Wrote:  I'm looking into the EDK2 firmware now. I was able to boot into EDK2, but it looks like the firmware expects the iPXE .efi file to be present on the SD card. I was hoping to have it netboot end-to-end starting with an empty SD card.

Michael, are you writing the iPXE files to an SD card first or do you have some netboot setup? I was searching for a way to embed iPXE as an EFI application into the EDK2 firmware or similar but it wasn't obvious whether this was supported. Thanks for the pointers!

I am writing bin-arm64-efi/rpi.efi to the SD card as /EFI/BOOT/BOOTAA64.EFI. It then gets booted automatically by the UEFI firmware. You could potentially use the EDK2 network boot stack instead to load iPXE via the network, but there's no real point in doing so since you have to write the UEFI firmware to the SD card anyway. (As another option: the Pi's built-in network boot mechanism using the VC4 firmware would allow you to boot without any SD card, but it is too unreliable for production use.)

I will soon get around to automating and publishing the build for this, so there will be a ready-built download available.

Michael