8 ms·

If you want to add an initrd, create an EFI payload: https://wiki.archlinux.org/title/Unified_kernel_image#Manually https://wiki.archlinux.org/title/Unified_ker

by csdvrx 4y ago

If you want to add an initrd, create an EFI payload: https://wiki.archlinux.org/title/Unified_kernel_image#Manually https://wiki.archlinux.org/title/Unified_kernel_image#Manual... $ stub_line=$(objdump -h "/usr/lib/systemd/boot/efi/linuxx64.efi.stub" | tail -2 | head -1) $ stub_size=0x$(echo "$stub_line" | awk '{print $3}') $ stub_offs=0x$(echo "$stub_line" | awk '{print $4}') $ osrel_offs=$((stub_size + stub_offs)) $ cmdline_offs=$((osrel_offs + $(stat -c%s "/usr/lib/os-release"))) $ splash_offs=$((cmdline_offs + $(stat -c%s "/etc/kernel/cmdline"))) $ linux_offs=$((splash_offs + $(stat -c%s "/usr/share/systemd/bootctl/splash-arch.bmp"))) $ initrd_offs=$((linux_offs + $(stat -c%s "vmlinuz-file"))) $ objcopy \ --add-section .osrel="/usr/lib/os-release" --change-section-vma .osrel=$(printf 0x%x $osrel_offs) \ --add-section .cmdline="/etc/kernel/cmdline" \ --change-section-vma .cmdline=$(printf 0x%x $cmdline_offs) \ --add-section .splash="/usr/share/systemd/bootctl/splash-arch.bmp" \ --change-section-vma .splash=$(printf 0x%x $splash_offs) \ --add-section .linux="vmlinuz-file" \ --change-section-vma .linux=$(printf 0x%x $linux_offs) \ --add-section .initrd="initrd-file" \ --change-section-vma .initrd=$(printf 0x%x $initrd_offs) \ "/usr/lib/systemd/boot/efi/linuxx64.efi.stub" "linux.efi" The resulting linux.efi" can be added directly with efibootmgr, and contains the kernel boot parameters (cmdline)

oxplot 4y ago
uh - you just specify the location of your initramfs in the kernel boot params and that's it, no need for all the above
- csdvrx 4y ago
  You hadn't specified it at first, so I thought it might be helpful to provide a more complete example with different parts (like the initrd) and offsets, with a gummiboot stub
- still_grokking 4y ago
  Having kernel and initrd separate makes things more complicated and brittle. Also a secure boot setup is much more difficult this way. I for my part love the UKI. Never had a simpler boot setup!
  - qu4z-2 4y ago
    > a secure boot setup is much more difficult this way. Is it? Don't you just sign the bootable kernel image that already has the initrd and command-line built in? Oh, I guess if you're using Microsoft as a CA I can see why that would be tricky.
    - still_grokking 4y ago
      I think this is a misunderstanding. I've said secure boot is much more difficult in case kernel and initrd are separate. In case of a UKI it's very simple of course. Just sign the boot image. That's why I love the UKI. :-)

by csdvrx 4y ago

oxplot 4y ago

uh - you just specify the location of your initramfs in the kernel boot params and that's it, no need for all the above

csdvrx 4y ago
You hadn't specified it at first, so I thought it might be helpful to provide a more complete example with different parts (like the initrd) and offsets, with a gummiboot stub
still_grokking 4y ago
Having kernel and initrd separate makes things more complicated and brittle. Also a secure boot setup is much more difficult this way. I for my part love the UKI. Never had a simpler boot setup!
- qu4z-2 4y ago
  > a secure boot setup is much more difficult this way. Is it? Don't you just sign the bootable kernel image that already has the initrd and command-line built in? Oh, I guess if you're using Microsoft as a CA I can see why that would be tricky.
  - still_grokking 4y ago
    I think this is a misunderstanding. I've said secure boot is much more difficult in case kernel and initrd are separate. In case of a UKI it's very simple of course. Just sign the boot image. That's why I love the UKI. :-)