Re: [PATCH 1/1] MdeModulePkg: fix !x86 builds (more)

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

Hi Leif,

On 08/27/19 14:43, Leif Lindholm wrote:
> Commit 4a1f6b85c184
> ("MdeModulePkg: add LockBoxNullLib for !IA32/X64 in .dsc")
> added an ARM/AARCH64 resolution for LockBoxLib. However, this failed
> to address the overrides provided for PEIM, DXE_DRIVER,
> DXE_RUNTIME_DRIVER, DXE_SMM_DRIVER and UEFI_DRIVER, so any modules
> of those classes still failed to build.
>
> Break these out properly into their own LibraryClasses sections.
>
> Resolves BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2134
>
> Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
> Reported-by: Baptiste Gerondeau <baptiste.gerondeau@linaro.org>
> Cc: Jian J Wang <jian.j.wang@intel.com>
> Cc: Hao A Wu <hao.a.wu@intel.com>
> ---
>
> I don't understand how the above would appear to work back when I
> submitted the previous patch but not work now, but I haven't dug
> into it deeper. Including the x86-specific LockBoxLib in the
> .common section is however clearly not correct.

I agree with you that the present situation is not correct.

According to:

  https://edk2-docs.gitbooks.io/edk-ii-dsc-specification/2_dsc_overview/26_[libraryclasses]_section_processing.html

the library class resolutions take effect in the following order
(entries near the top have higher priority):

> 1. <LibraryClasses> associated with the INF file in the [Components] section
> 2. [LibraryClasses.$(Arch).$(MODULE_TYPE), LibraryClasses.$(Arch).$(MODULE_TYPE)]
> 3. [LibraryClasses.$(Arch).$(MODULE_TYPE)]
> 4. [LibraryClasses.common.$(MODULE_TYPE)]
> 5. [LibraryClasses.$(Arch)]
> 6. [LibraryClasses.common] or [LibraryClasses]

(Side comment 1: levels #2 and #3 look very similar; I think the
difference is that #2 is supposed to be a multi-arch and/or
multi-module-type section, while #3 is a single-arch and
single-module-type section.)

Commit 4a1f6b85c184 ("MdeModulePkg: add LockBoxNullLib for !IA32/X64 in
.dsc", 2019-03-27) provided a LockBoxLib resolution at level #5:

> [LibraryClasses.ARM, LibraryClasses.AARCH64]

However, the other LockBoxLib resolutions are at level #4:

> [LibraryClasses.common.PEIM]
> [LibraryClasses.common.DXE_DRIVER]
> [LibraryClasses.common.DXE_RUNTIME_DRIVER]
> [LibraryClasses.common.DXE_SMM_DRIVER]
> [LibraryClasses.common.UEFI_DRIVER]

So the latter taking priority is actually specified behavior.

(Side comment 2: EBC is in the same boat, from commit cbcccd2c9d93
("Update Code to pass EBC compiler", 2013-05-13):

> [LibraryClasses.EBC]
>   LockBoxLib|MdeModulePkg/Library/LockBoxNullLib/LockBoxNullLib.inf
)

As to why this breakage was not exposed right at commit 4a1f6b85c184 --
I have no idea. Perhaps it was hidden by a BaseTools issue that has been
fixed meanwhile.

On 08/27/19 14:43, Leif Lindholm wrote:
> I think a fix for this issue needs to go into 2019.08,

I agree the problem should be fixed in 2019.08 -- taking your word that
commit 4a1f6b85c184 *appeared* to fix the MdeModulePkg.dsc build for
ARM/AARCH64, we now have a regression since that commit (dated
2019-03-27).

> but if someone has a prettier suggestion, I am not wedded to this one.

I think this is good enough. The lib class resolutions are raised to
level #2, but they will no longer match ARM / AARCH64, so your level#5
addition from commit 4a1f6b85c184 will take effect.

>
>  MdeModulePkg/MdeModulePkg.dsc | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/MdeModulePkg/MdeModulePkg.dsc b/MdeModulePkg/MdeModulePkg.dsc
> index 4320839abfb5..15ba96cecbed 100644
> --- a/MdeModulePkg/MdeModulePkg.dsc
> +++ b/MdeModulePkg/MdeModulePkg.dsc
> @@ -109,6 +109,8 @@ [LibraryClasses.common.PEIM]
>    HobLib|MdePkg/Library/PeiHobLib/PeiHobLib.inf
>    MemoryAllocationLib|MdePkg/Library/PeiMemoryAllocationLib/PeiMemoryAllocationLib.inf
>    ExtractGuidedSectionLib|MdePkg/Library/PeiExtractGuidedSectionLib/PeiExtractGuidedSectionLib.inf
> +
> +[LibraryClasses.IA32.PEIM,LibraryClasses.X64.PEIM]
>    LockBoxLib|MdeModulePkg/Library/SmmLockBoxLib/SmmLockBoxPeiLib.inf

(1) I suggest replacing "," with ", ". (That's more consistent with
preexistent section headers in the DSC file.) Applies to the other new
section headers too.

>
>  [LibraryClasses.common.DXE_CORE]
> @@ -118,18 +120,22 @@ [LibraryClasses.common.DXE_CORE]
>
>  [LibraryClasses.common.DXE_DRIVER]
>    HobLib|MdePkg/Library/DxeHobLib/DxeHobLib.inf
> -  LockBoxLib|MdeModulePkg/Library/SmmLockBoxLib/SmmLockBoxDxeLib.inf
>    MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
>    ExtractGuidedSectionLib|MdePkg/Library/DxeExtractGuidedSectionLib/DxeExtractGuidedSectionLib.inf
>    CapsuleLib|MdeModulePkg/Library/DxeCapsuleLibFmp/DxeCapsuleLib.inf
>
> +[LibraryClasses.IA32.DXE_DRIVER,LibraryClasses.X64.DXE_DRIVER]
> +  LockBoxLib|MdeModulePkg/Library/SmmLockBoxLib/SmmLockBoxDxeLib.inf
> +
>  [LibraryClasses.common.DXE_RUNTIME_DRIVER]
>    HobLib|MdePkg/Library/DxeHobLib/DxeHobLib.inf
>    MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
>    DebugLib|MdePkg/Library/UefiDebugLibConOut/UefiDebugLibConOut.inf
> -  LockBoxLib|MdeModulePkg/Library/SmmLockBoxLib/SmmLockBoxDxeLib.inf
>    CapsuleLib|MdeModulePkg/Library/DxeCapsuleLibFmp/DxeRuntimeCapsuleLib.inf
>
> +[LibraryClasses.IA32.DXE_RUNTIME_DRIVER,LibraryClasses.X64.DXE_RUNTIME_DRIVER]
> +  LockBoxLib|MdeModulePkg/Library/SmmLockBoxLib/SmmLockBoxDxeLib.inf
> +
>  [LibraryClasses.common.SMM_CORE]
>    HobLib|MdePkg/Library/DxeHobLib/DxeHobLib.inf
>    MemoryAllocationLib|MdeModulePkg/Library/PiSmmCoreMemoryAllocationLib/PiSmmCoreMemoryAllocationLib.inf
> @@ -143,13 +149,17 @@ [LibraryClasses.common.DXE_SMM_DRIVER]
>    MemoryAllocationLib|MdePkg/Library/SmmMemoryAllocationLib/SmmMemoryAllocationLib.inf
>    MmServicesTableLib|MdePkg/Library/MmServicesTableLib/MmServicesTableLib.inf
>    SmmServicesTableLib|MdePkg/Library/SmmServicesTableLib/SmmServicesTableLib.inf
> +  SmmMemLib|MdePkg/Library/SmmMemLib/SmmMemLib.inf
> +
> +[LibraryClasses.IA32.DXE_SMM_DRIVER,LibraryClasses.X64.DXE_SMM_DRIVER]
>    LockBoxLib|MdeModulePkg/Library/SmmLockBoxLib/SmmLockBoxSmmLib.inf
> -  SmmMemLib|MdePkg/Library/SmmMemLib/SmmMemLib.inf
>

I wonder if this is really necessary. I would assume all the
DXE_SMM_DRIVER modules are listed under

  [Components.IA32, Components.X64]

already. But, this hunk certainly doesn't hurt.

>  [LibraryClasses.common.UEFI_DRIVER]
>    HobLib|MdePkg/Library/DxeHobLib/DxeHobLib.inf
>    MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
>    DebugLib|MdePkg/Library/UefiDebugLibConOut/UefiDebugLibConOut.inf
> +
> +[LibraryClasses.IA32.UEFI_DRIVER,LibraryClasses.X64.UEFI_DRIVER]
>    LockBoxLib|MdeModulePkg/Library/SmmLockBoxLib/SmmLockBoxDxeLib.inf
>
>  [LibraryClasses.common.UEFI_APPLICATION]
>

With (1) fixed (feel free to correct that just before pushing):

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

Do wait for maintainer review, of course.

Thanks,
Laszlo