Re: [PATCH 0/4] linux: implement LoadFile2 initrd loading

[Leif Lindholm]

On Fri, Oct 23, 2020 at 14:08:21 +0200, Ard Biesheuvel wrote:
> This implements the LoadFile2 initrd loading protocol, which is
> essentially a callback face into the bootloader to load the initrd
> data into a caller provided buffer. This means the bootloader no
> longer has to contain any policy regarding where to load the initrd
> (which differs between architectures and kernel versions) and no
> longer has to manipulate arch specific data structures such as DT
> or struct bootparams to inform the OS where the initrd resides in
> memory.
> 
> Sample output from booting a recent Linux/arm64 kernel:
> 
>   grub> insmod part_msdos
>   grub> linux (hd0,msdos1)/Image
>   grub> initrd (hd0,msdos1)/initrd.img
>   grub> boot
>   EFI stub: Booting Linux Kernel...
>   EFI stub: EFI_RNG_PROTOCOL unavailable, KASLR will be disabled
>   EFI stub: Generating empty DTB
>   EFI stub: Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path
>   EFI stub: Exiting boot services and installing virtual address map...
>   [    0.000000] Booting Linux on physical CPU 0x0000000000 [0x411fd070]

I don't review enough grub code to be certain I've caught all aspects
of style adherence, so with that in mind, for 1-2/4:
Reviewed-by: Leif Lindholm <leif@nuviainc.com>

For 3-4/4, I did have some minor comments, but this is a really great
feature and I would like to see it merged.

/
    Leif

> Cc: grub-devel@gnu.org
> Cc: daniel.kiper@oracle.com
> Cc: leif@nuviainc.com
> 
> Ard Biesheuvel (4):
>   loader/linux: permit NULL argument for argv[] in grub_initrd_load()
>   efi: add definition of LoadFile2 protocol
>   efi: implemented LoadFile2 initr loading protocol for Linux
>   linux: ignore FDT unless we need to modify it
> 
>  grub-core/commands/efi/lsefi.c |   1 +
>  grub-core/loader/arm64/linux.c | 139 ++++++++++++++++++--
>  grub-core/loader/efi/fdt.c     |   7 +-
>  grub-core/loader/linux.c       |   2 +-
>  include/grub/efi/api.h         |  15 +++
>  5 files changed, 149 insertions(+), 15 deletions(-)
> 
> -- 
> 2.17.1
>