[PATCH 0/8 v2] Change logic of EFI LoadFile2 protocol for initrd loading

[Heinrich Schuchardt]

On 12/30/20 4:07 PM, Ilias Apalodimas wrote:
> Hi!
>
> This is v2 of [1].
>
> There's been a couple of changes regarding where we install the protocol.
> The initial patchset was completely disregarding BootNext, so that's taken
> into account now and we can use the new feature.
> This brought a few changes on the selftests as well, since we now use the
> loaded image handle to install the protocol, as a consequence the custom
> handle in the tests is now uninstalled during the test .teardown(), but
> the overall approach remains identical.

Boot#### contains a device path.

Why should Initrd#### contain something U-Boot specific and not a device
path?

Think of a Linux distribution. When updating the kernel it will have to
write Boot#### and Initrd####. It can determine the current boot device
via BootCurrent and Boot####. Next it can add the new file paths for
Boot#### and Initrd#### relative to the same device.

Best regards

Heinrich

>
> Changes since v1:
> - Use efi_create_indexed_name() instead of open coding it. An extra
>    patch has been applied to efi_create_indexed_name() to ensure the
>    destination buffer is big enough for our variable name.
> - Install the protocol during do_efibootmgr() on the loaded image
>    handle and adjust selftests accordingly. The protocol will be
>    uninstalled if efi_exit() is called from and EFI app now.
> - Make sure strings are null terminated in efi_helper.c
> - Added documentation in uefi.rst describing the new feature.
>
> [1] https://lists.denx.de/pipermail/u-boot/2020-December/436080.html
>
> Ilias Apalodimas (8):
>    efi_loader: Remove unused headers from efi_load_initrd.c
>    efi_loader: Remove unconditional installation of file2 protocol for
>      initrd
>    efi_loader: Add size checks to efi_create_indexed_name()
>    efi_loader: Introduce helper functions for EFI
>    efi_loader: bootmgr: Use get_var from efi_helper file
>    efi_loader: Replace config option with EFI variable for initrd loading
>    efi_selftest: Modify self-tests for initrd loading via Loadfile2
>    doc: uefi: Add instruction for initrd loading
>
>   cmd/bootefi.c                               |  13 ++
>   doc/uefi/uefi.rst                           |  15 ++
>   include/efi_helper.h                        |  28 +++
>   include/efi_loader.h                        |   5 +-
>   lib/efi_loader/Kconfig                      |  13 +-
>   lib/efi_loader/Makefile                     |   2 +-
>   lib/efi_loader/efi_bootmgr.c                |  37 +---
>   lib/efi_loader/efi_helper.c                 | 180 ++++++++++++++++++++
>   lib/efi_loader/efi_load_initrd.c            | 101 ++++-------
>   lib/efi_loader/efi_setup.c                  |   5 -
>   lib/efi_loader/efi_string.c                 |  10 +-
>   lib/efi_selftest/efi_selftest_load_initrd.c | 100 ++++++++++-
>   test/unicode_ut.c                           |   2 +-
>   13 files changed, 384 insertions(+), 127 deletions(-)
>   create mode 100644 include/efi_helper.h
>   create mode 100644 lib/efi_loader/efi_helper.c
>