[PATCH 00/10] bootm: Clean up arch-specific, pre-OS clean-up

[Simon Glass]

Hi Peter,

On Tue, 6 Jan 2026 at 19:29, Peter Robinson <pbrobinson at gmail.com> wrote:
>
> Hi Simon,
>
> > Each arch does something slightly different before booting the OS. Some
> > archs even do different things depending on the CPU type.
> >
> > EFT_LOADER has its own special code, regardless of which arch is being
> > booted.
> >
> > It is quite hard to know what actually happens in the final milliseconds
> > before the OS boot.
> >
> > This series attempts to clean up U-Boot in this area.
> >
> > The basic approach is to create a new bootm_final() function which is
> > called by all archs. It provides some flags for a couple of necessary
> > variations but otherwise it is generic.
> >
> > RISC-V, x86 and ARM are converted over to use this new function. For
> > consistency, EFI loader is converted as well.
> >
> > A noteable change is that EFI_LOADER now does bootstage processing
> > before boot, if enabled, thus producing a report.
>
> Why is the change needed, I don't see it explained in the patches or
> here and what the implications might be.

At present EFI_LOADER ignores bootstage and so there is no timing
report produced even if enabled. It was probably an oversight.

>
> > There is also a patch to drop EFI_GRUB_ARM32_WORKAROUND, as discussed
> > recently on the mailing list.
>
> That appears to be unrelated to this series, it should be a separate
> standalone patch else it needs to be described here why it's a
> dependency, and even then likely still posted separately as a
> dependency of this series.

In what way is it unrelated? In my view this is related as it is a
pre-OS cleanup. What do you mean by dependency here?

>
> > Future work could take this a little further:
> > - Drop board_quiesce_devices() and rely on driver model for that
> > - Similarly with udc_disconnect(),
> > - cleanup_before_linux() could use more details as to what it is
> > supposed to do, to reduce the number of arch-specific variations
>
> What do you mean by that statement.

Well, the function does different things on differents archs and is
mostly uncommented (apart from an ARM-specific note in a README).
Ideally it would be commented with exactly what it should do, ideally
at a high level so it is not just arch-specific.


>
> > Note: This is the first 10 patches for an 18-part series from the
> > Concept tree, as requested. The patches after that complete the cleanup
> > on ARM and RISC-V.
> >
> >
> > Simon Glass (10):
> >   boot: Create a function for final pre-boot steps
> >   efi: Make use of bootm_final()
> >   bootm: Add a message when booting
> >   bootstage: Add some missing dummy functions
> >   bootm: Do bootstage processing in bootm_final()
> >   x86: Call bootm_final()
> >   riscv: Drop board_quiesce_devices()
> >   riscv: Call bootm_final()
> >   efi: Drop EFI_GRUB_ARM32_WORKAROUND
> >   x86: Add cleanup_before_linux()
> >
> >  MAINTAINERS                           |  1 +
> >  arch/riscv/include/asm/u-boot-riscv.h |  1 -
> >  arch/riscv/lib/bootm.c                | 24 +------------------
> >  arch/x86/cpu/cpu.c                    |  5 ++++
> >  arch/x86/lib/bootm.c                  | 14 +----------
> >  boot/Makefile                         |  2 +-
> >  boot/bootm_final.c                    | 34 +++++++++++++++++++++++++++
> >  configs/mt7623n_bpir2_defconfig       |  1 -
> >  include/bootm.h                       | 17 ++++++++++++++
> >  include/bootstage.h                   |  8 +++++++
> >  lib/efi_loader/Kconfig                | 10 --------
> >  lib/efi_loader/efi_boottime.c         | 30 +----------------------
> >  test/boot/bootflow.c                  |  2 +-
> >  13 files changed, 70 insertions(+), 79 deletions(-)
> >  create mode 100644 boot/bootm_final.c
> >
> > --
> > 2.43.0
> >
> > base-commit: 6cdd7597a2fbfc1572c1b0af23d3daf1cefa2de7
> > branch: bootma-us