Reviewed-by: Yonghong Zhu <[email protected]> Best Regards, Zhu Yonghong
-----Original Message----- From: Kinney, Michael D Sent: Wednesday, May 31, 2017 2:00 PM To: [email protected] Cc: Gao, Liming <[email protected]>; Zhu, Yonghong <[email protected]>; Shaw, Kevin W <[email protected]> Subject: [edk2-DscSpecification PATCH v2] Update Precedence of PCD Values https://bugzilla.tianocore.org/show_bug.cgi?id=519 Cc: Liming Gao <[email protected]> Cc: Yonghong Zhu <[email protected]> Cc: Kevin W Shaw <[email protected]> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Michael Kinney <[email protected]> --- 2_dsc_overview/28_pcd_section_processing.md | 56 ++++++++++++++--------------- README.md | 1 + 2 files changed, 29 insertions(+), 28 deletions(-) diff --git a/2_dsc_overview/28_pcd_section_processing.md b/2_dsc_overview/28_pcd_section_processing.md index 0969b41..1adde81 100644 --- a/2_dsc_overview/28_pcd_section_processing.md +++ b/2_dsc_overview/28_pcd_section_processing.md @@ -320,45 +320,45 @@ string plus 1 byte for the null terminator, for L"string" entries to be the length of the UCS-2 character string plus 2 bytes for the null terminator and the exact length of a byte array. -Precedence for determining PCD values (high to low, last in position) is as -follows: +The values that are assigned to individual PCDs required by a build may +come from different locations and different meta-data files. The +following provides the precedence (high to low) to assign a value to a PCD. -* A PCD value defined by a MACRO, ("MacroName" in this example), and the Macro - is defined on the command-line using -D MacroName=Value +* Command-line, `--pcd` flags (left most has higher priority) -* A PCD value defined in the FDF file SET statements +* DSC file, FeatureFlag, PatchableInModule or FixedAtBuild PCD value +defined + in the `[Components]` INF scoping `<Pcd*>` section statements -* A PCD value defined positionally in the FDF file +* FDF file, grammar describing automatic assignment of PCD values -* A FeatureFlag, PatchableInModule or FixedAtBuild PCD value defined in the - `[Components]` INF scoping section +* FDF file, SET statements within a section -* A FeatureFlag, PatchableInModule or FixedAtBuild PCD value defined in a PCD - access method section with an architectural modifier (the access method for a - PCD in a section with an architectural modifier takes precedence over any - other access method) +* FDF file, SET statement in the [Defines] section -In this example, modules built for IA32 architecture, the PCD will use -PatchableInModule access, while modules built for all other architectures, the -PCD will use the FixedAtBuild access method: +* DSC file, a PCD value defined in a PCD access method section with an + architectural modifier. -```ini -[PcdsFixedAtBuild.common] - gEfiMdeModulePkgTokenSpaceGuid.PcdStatusCodeMemorySize|1 - gEfiMdeModulePkgTokenSpaceGuid.PcdResetOnMemoryTypeInformationChange|FALSE + In this example, modules built for IA32 architecture, the PCD will + use PatchableInModule access, while modules built for all other + architectures, the PCD will use the FixedAtBuild access method: -[PcdsPatchableInModule.IA32] - gEfiMdeModulePkgTokenSpaceGuid.PcdStatusCodeMemorySize|1 - gEfiMdeModulePkgTokenSpaceGuid.PcdResetOnMemoryTypeInformationChange|FALSE -``` + ```ini + [PcdsFixedAtBuild.common] + gEfiMdeModulePkgTokenSpaceGuid.PcdStatusCodeMemorySize|1 + + gEfiMdeModulePkgTokenSpaceGuid.PcdResetOnMemoryTypeInformationChange|F + ALSE + + [PcdsPatchableInModule.IA32] + gEfiMdeModulePkgTokenSpaceGuid.PcdStatusCodeMemorySize|1 + + gEfiMdeModulePkgTokenSpaceGuid.PcdResetOnMemoryTypeInformationChange|F + ALSE + ``` -* A PCD value defined in a PCD access method (item type) section for common - architectures +* DSC file, A PCD value defined in a PCD access method (item type) +global + `[Pcd*]` section for common architectures. -* A PCD value defined in an INF (provided all INF files have defined the same - value) +* INF file, PCD sections, Default Values (provided all INF files have +defined + the same value) -* A PCD default value defined in the DEC file that declares the PCD. +* DEC file, PCD sections, Default Values ********** **Note:** Dynamic or DynamicEx PCD sections with architectural modifiers is not diff --git a/README.md b/README.md index eb6966f..5e2c17a 100644 --- a/README.md +++ b/README.md @@ -181,3 +181,4 @@ Copyright (c) 2006-2017, Intel Corporation. All rights reserved. | | [#484](https://bugzilla.tianocore.org/show_bug.cgi?id=484) DSC spec: support Prebuild and Postbuild in the [Defines] section | | | | [#353](https://bugzilla.tianocore.org/show_bug.cgi?id=353) Build spec: Allow nested includes in DSC and FDF files | | | | [#521](https://bugzilla.tianocore.org/show_bug.cgi?id=521) DSC spec: add clarification for mixed PCD usage in the DSC spec | | +| | [#519](https://bugzilla.tianocore.org/show_bug.cgi?id=519) DSC Spec: update Precedence of PCD Values | | -- 2.6.3.windows.1 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
