Re: [edk2-devel] [PATCH 4/7] MdeModulePkg/UefiBootManagerLib: export EfiBootManagerGetBootDescription()

["Laszlo Ersek" <lersek@redhat.com>]

On 06/22/19 00:31, David Woodhouse wrote:
> It would be useful for LegacyBiosDxe to be able to get descriptive names
> for block devices, for legacy boot options. It gets a bit confusing when
> they're all called "Harddisk".
> 
> Since we have a collection of the special cases for various types of
> device already in BmGetBootDescription(), let's export that with a
> minor tweak to let the caller set the "UEFI " vs. "Legacy " prefix.
> 
> There's no way we want to reproduce all those device-specific special
> cases again in the LegacyBiosDxe. It's bad enough that they exist in
> UefiBootManagerLib in the first place, instead of being in a protocol
> provided by the individual disk drivers themselves.
> 
> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
> ---
>  .../Include/Library/UefiBootManagerLib.h      | 16 ++++++++++++
>  .../UefiBootManagerLib/BmBootDescription.c    | 26 ++++++++++++++++---
>  2 files changed, 38 insertions(+), 4 deletions(-)
> 
> diff --git a/MdeModulePkg/Include/Library/UefiBootManagerLib.h b/MdeModulePkg/Include/Library/UefiBootManagerLib.h
> index 0b69a6021d..a9d6bfda88 100644
> --- a/MdeModulePkg/Include/Library/UefiBootManagerLib.h
> +++ b/MdeModulePkg/Include/Library/UefiBootManagerLib.h
> @@ -249,6 +249,22 @@ EfiBootManagerFindLoadOption (
>    IN UINTN                              Count
>    );
>  
> +/**
> +  Return the boot description for the controller.
> +
> +  @param Prefix                String prefix (e.g "UEFI " or "Legacy ").
> +  @param Handle                Controller handle.
> +
> +  @return  The description string.
> +**/
> +CHAR16 *
> +EFIAPI
> +EfiBootManagerGetBootDescription (
> +  IN CHAR16                     *Prefix,
> +  IN EFI_HANDLE                  Handle
> +  );
> +
> +
>  //
>  // Boot Manager hot key library functions.
>  //
> diff --git a/MdeModulePkg/Library/UefiBootManagerLib/BmBootDescription.c b/MdeModulePkg/Library/UefiBootManagerLib/BmBootDescription.c
> index aa891feb17..dd4d160f31 100644
> --- a/MdeModulePkg/Library/UefiBootManagerLib/BmBootDescription.c
> +++ b/MdeModulePkg/Library/UefiBootManagerLib/BmBootDescription.c
> @@ -758,12 +758,15 @@ BM_GET_BOOT_DESCRIPTION mBmBootDescriptionHandlers[] = {
>  /**
>    Return the boot description for the controller.
>  
> +  @param Prefix                String prefix (e.g "UEFI " or "Legacy ").
>    @param Handle                Controller handle.
>  
>    @return  The description string.
>  **/
>  CHAR16 *
> -BmGetBootDescription (
> +EFIAPI
> +EfiBootManagerGetBootDescription (
> +  IN CHAR16                     *Prefix,
>    IN EFI_HANDLE                  Handle
>    )
>  {
> @@ -785,10 +788,10 @@ BmGetBootDescription (
>        // Avoid description confusion between UEFI & Legacy boot option by adding "UEFI " prefix
>        // ONLY for core provided boot description handler.
>        //
> -      Temp = AllocatePool (StrSize (DefaultDescription) + sizeof (mBmUefiPrefix));
> +      Temp = AllocatePool (StrSize (DefaultDescription) + StrSize (Prefix));
>        ASSERT (Temp != NULL);
> -      StrCpyS (Temp, (StrSize (DefaultDescription) + sizeof (mBmUefiPrefix)) / sizeof (CHAR16), mBmUefiPrefix);
> -      StrCatS (Temp, (StrSize (DefaultDescription) + sizeof (mBmUefiPrefix)) / sizeof (CHAR16), DefaultDescription);
> +      StrCpyS (Temp, (StrSize (DefaultDescription) + StrSize (Prefix)) / sizeof (CHAR16), Prefix);
> +      StrCatS (Temp, (StrSize (DefaultDescription) + StrSize (Prefix)) / sizeof (CHAR16), DefaultDescription);
>        FreePool (DefaultDescription);
>        DefaultDescription = Temp;
>        break;

I first thought this would be redundant wrt. platform description
handlers registered with EfiBootManagerRegisterBootDescriptionHandler(),
which BmGetBootDescription() asks for "better" descriptions.

But, in such a platform callback, we'd still only want to rely on
"mBmBootDescriptionHandlers", just with a different prefix. So this idea
looks fine to me, after all.

> @@ -814,6 +817,21 @@ BmGetBootDescription (
>    return DefaultDescription;
>  }
>  
> +/**
> +  Return the boot description for the controller, for UEFI boot.
> +
> +  @param Handle                Controller handle.
> +
> +  @return  The description string.
> +**/
> +CHAR16 *
> +BmGetBootDescription (
> +  IN EFI_HANDLE                  Handle
> +  )
> +{
> +  return EfiBootManagerGetBootDescription(mBmUefiPrefix, Handle);

I noticed this elsewhere (in earlier patches in this series) but I
didn't want to annoy you with obsessing about it :)

(1) Please insert a space character before the opening paren, after the
function designator. (Applies to the sizeof operator, and to
function-like macro invocations, too.)

With this fixed:

Reviewed-by: Laszlo Ersek <lersek@redhat.com>

Thanks

> +}
> +
>  /**
>    Enumerate all boot option descriptions and append " 2"/" 3"/... to make
>    unique description.
>