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For those interested: nowadays Linux has support for what is called the EFI Stub boot, which allows the kernel to be booted directly by UEFI. So in a sense step

For those interested: nowadays Linux has support for what is called the EFI Stub boot, which allows the kernel to be booted directly by UEFI. So in a sense steps 1-3 are rolled into the kernel, and the kernel acts as its own boot loader.

chungy 8y ago
Wouldn't it rather just be UEFI taking place of steps 1-3? The kernel becomes a PE binary instead of an ELF one, but I get the sense that it's basically the same thing...?
secure 8y ago
Do you know of any major distributions using this mechanism? I’ve only ever seen GRUB on UEFI.
- rl3 8y ago
  Arch supports it: https://wiki.archlinux.org/index.php/EFISTUB https://wiki.archlinux.org/index.php/EFISTUB Being able to directly edit your motherboard's EFI boot order via command line is admittedly pretty neat. That said, using a traditional bootloader seems to be a popular choice still for simplicity and portability reasons. EFISTUB also can make certain crypto setups more difficult as far as I'm aware.
  - checkyoursudo 8y ago
    On Gentoo, for a couple of years, I used an initramfs compiled into the kernel to boot via EFI_STUB with full disk encryption. It's possible. It's been a while. I don't remember it being very easy to wrangle. I don't use that laptop anymore, but I still boot via EFI_STUB on my desktop. It's super simple to set up when you're not using FDE. I don't remember there being any specific problem that make some crypto setups more difficult than others, with the caveat that implementing FDE at all makes EFI_STUB somewhat more complicated no matter what. Like I said, it's been a couple of years since I figured all that stuff out, so the passage of time may have softened the terror of configuration and clouded my memories.
    - rl3 8y ago
      >... the terror of configuration ... That's an excellent way of phrasing it.
- checkyoursudo 8y ago
  I have been booting an EFI_STUB kernel in Gentoo for several years. It's pretty easy to do. See, e.g., https://wiki.gentoo.org/wiki/EFI_stub_kernel https://wiki.gentoo.org/wiki/EFI_stub_kernel

chungy 8y ago

Wouldn't it rather just be UEFI taking place of steps 1-3? The kernel becomes a PE binary instead of an ELF one, but I get the sense that it's basically the same thing...?

secure 8y ago

Do you know of any major distributions using this mechanism? I’ve only ever seen GRUB on UEFI.

rl3 8y ago
Arch supports it: https://wiki.archlinux.org/index.php/EFISTUB https://wiki.archlinux.org/index.php/EFISTUB Being able to directly edit your motherboard's EFI boot order via command line is admittedly pretty neat. That said, using a traditional bootloader seems to be a popular choice still for simplicity and portability reasons. EFISTUB also can make certain crypto setups more difficult as far as I'm aware.
- checkyoursudo 8y ago
  On Gentoo, for a couple of years, I used an initramfs compiled into the kernel to boot via EFI_STUB with full disk encryption. It's possible. It's been a while. I don't remember it being very easy to wrangle. I don't use that laptop anymore, but I still boot via EFI_STUB on my desktop. It's super simple to set up when you're not using FDE. I don't remember there being any specific problem that make some crypto setups more difficult than others, with the caveat that implementing FDE at all makes EFI_STUB somewhat more complicated no matter what. Like I said, it's been a couple of years since I figured all that stuff out, so the passage of time may have softened the terror of configuration and clouded my memories.
  - rl3 8y ago
    >... the terror of configuration ... That's an excellent way of phrasing it.
checkyoursudo 8y ago
I have been booting an EFI_STUB kernel in Gentoo for several years. It's pretty easy to do. See, e.g., https://wiki.gentoo.org/wiki/EFI_stub_kernel https://wiki.gentoo.org/wiki/EFI_stub_kernel