Thread (6 messages) 6 messages, 3 authors, 7d ago

Re: [PATCH 00/19] init: discoverable root partitions, a.k.a. an omittable "root=" cmdline option

From: Vincent Mailhol <mailhol@kernel.org>
Date: 2026-06-15 20:33:21
Also in: linux-alpha, linux-arm-kernel, linux-block, linux-doc, linux-efi, linux-fsdevel, linux-mips, linux-riscv, linux-s390, lkml, loongarch

On 15/06/2026 at 19:04, Al Viro wrote:
On Mon, Jun 15, 2026 at 06:08:56PM +0200, Vincent Mailhol wrote:
quoted
Tested with GRUB, which implements the LoaderDevicePartUUID EFI variable
in its bli module [3]. With this, I was able to boot a kernel with a
completely empty cmdline and no initrd.

[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/

[2] systemd-gpt-auto-generator
Link: https://www.freedesktop.org/software/systemd/man/latest/systemd-gpt-auto-generator.html

[3] GRUB -- §16.2 bli
Link: https://www.gnu.org/software/grub/manual/grub/html_node/bli_005fmodule.html
So what does that thing, tied to EFI as it is, have to do with architectures where
	* firmware is rather unlike EFI
I made CONFIG_DPS_ROOT_AUTO_DISCOVERY depend on CONFIG_EFI for this reason.
	* firmware wouldn't know what to do with GPT
	* GRUB is *not* ported to, let alone used
such as, say it, the very first one mentioned at your [1]?
Fair point. I just did:

  $ git grep "^config EFI$"
  arch/arm/Kconfig:config EFI
  arch/arm64/Kconfig:config EFI
  arch/loongarch/Kconfig:config EFI
  arch/riscv/Kconfig:config EFI
  arch/x86/Kconfig:config EFI

Anything not in this list is dead code at the moment.
Or is that conditional upon "if anyone wants to design replacement firmware
for those, and if they agree to follow our wishlist"?
No, it was just an oversight from my side. I will just keep arm, arm64,
loongarch, riscv and x86 in my v2.


Yours sincerely,
Vincent Mailhol

Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help