[Armbian build PR] - rk3588: experimental UEFI edk2 support

rk3588: experimental UEFI edk2 support

• core extensions: fix: don't redefine extension_function_info when recursing
  • otherwise when there's a chain of enable_extension() we lose the original info
• extensions: grub-with-dtb: add UMS menu entry to GRUB if initramfs ums hook is detected
  • this allows user to enter UMS mode from GRUB
  • for usage with the initramfs-usb-gadget-ums extension
  • has no effect unless initramfs-usb-gadget-ums extension is enabled together with grub-with-dtb
• extensions: initramfs-usb-gadget-ums: kernel cmdline enables initramfs UMS of all block devices
  • this optional extension adds an initramfs script that:
    • enumerates and filters all block devices
    • exposes each device as an UMS (USB Mass Storage) in an USB Gadget
    • loops forever with info (board never boots)
  • the idea here is to compensate for UEFI's lack of "ums" or "rockusb" mode that's present in u-boot
  • it also allows to expose USB/NVMe devices that might or not be detected by bootloader, if the kernel works
• extensions: uefi-edk2-rk3588: deploy edk2 (not u-boot) for rk3588 boards
  • this extension is 100% optional and shouldn't adversely affect any builds if not enabled
  • requires UEFI_EDK2_BOARD_ID to be set in board file, so we know which UEFI/edk2 build to use
  • it finds the latest edk2 version from GitHub automatically (currently v0.9.1)
  • it downloads (and caches) the correct edk2 build image automatically
  • if forces certain aspects of the image:
    • must use GPT partitioning
    • must NOT use a separate /boot partition
  • it disables the building and deploying of u-boot completely (thus blobs etc are from edk2)
  • it creates a GPT "uboot" partition pointing to edk2's FIT, required by SPL
  • this extension:
    • automatically enables 'grub-with-dtb'
    • automatically enable 'initramfs-usb-gadget-ums', to compensate for lack of ums/rockusb since we dont have u-boot anymore
• rk3588: configure UEFI_EDK2_BOARD_ID for all UEFI-supported boards
  • From https://github.com/edk2-porting/edk2-rk3588/releases/tag/v0.9.1
    • For example, for rock-5b_UEFI_Release_v0.9.1.img
      • UEFI_EDK2_BOARD_ID is rock-5b
  • Important: this has no effect unless optional extension is enabled
  • to test this out:
    • make sure to read carefully the instructions at https://github.com/edk2-porting/edk2-rk3588/blob/master/README.md
    • suppose you previously built the regular u-boot version with:
      • ./compile.sh BOARD=rock-5b BRANCH=legacy RELEASE=jammy
    • now you can build the UEFI version with:
      • ./compile.sh BOARD=rock-5b BRANCH=legacy RELEASE=jammy EXT=uefi-edk2-rk3588
    • write the produced image to SD or eMMC and boot it
    • use normally, or enter "UMS" mode by selecting that option in the grub menu
      • You can write image to eMMC, boot it, enter UMS, write it again to NVMe, reboot, press in UEFI and boot from NVMe
      • Also works if .img is written to eg USB stick, and UEFI edk2 is separately deployed to SPI flash
  • Important: make absolutely sure you are able to force Maskrom mode (by shorting pins, pressing buttons, etc) before writing an UEFI image to eMMC; UEFI has no RockUSB ("Loader mode" support) at all. The new "initramfs-usb-gadget-ums" extension hopes to address this, but it is not guaranteed to work.

View the full article