[PATCH 2/2 v4] efi: Add basic EFI_TCG2_PROTOCOL support

[Simon Glass <sjg@chromium.org>]

Hi Ilias,

On Wed, 11 Nov 2020 at 02:18, Ilias Apalodimas
<ilias.apalodimas@linaro.org> wrote:
>
> Since U-boot EFI implementation is getting richer it makes sense to
> add support for EFI_TCG2_PROTOCOL taking advantage of any hardware TPM
> available on the device.
>
> This is the initial implementation of the protocol which only adds
> support for GetCapability(). It's limited in the newer and safer
> TPMv2 devices.
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> ---
> * changes since v3:
> - added check for maximum number of PCRs allowed
> - replaced multiple return Xl with goto out tags
> * changes since v2:
> - added description about include/efi_tcg2.h
> - switch bool to u8 for tpm_present_flag
> - removed superfluous 'default n' from Kconfig
> - use 'goto 'tag' when possible
>
> * changes since v1:
> - change return variable of platform_get_tpm2_device() when used
> - since more headers were included in patch #2 use them in offset
>   calculations for all tpm commands
> - change the size of the response buffer regardless of what
>   tpm2_get_capability() is doing
>  include/efi_loader.h       |   2 +
>  include/efi_tcg2.h         |  94 +++++++
>  lib/efi_loader/Kconfig     |   7 +
>  lib/efi_loader/Makefile    |   1 +
>  lib/efi_loader/efi_setup.c |   7 +
>  lib/efi_loader/efi_tcg2.c  | 539 +++++++++++++++++++++++++++++++++++++
>  6 files changed, 650 insertions(+)
>  create mode 100644 include/efi_tcg2.h
>  create mode 100644 lib/efi_loader/efi_tcg2.c

I will let Heinrich review this one. I do feel that the overly long
identifiers make the code hard to read.

Regards,
Simon