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7a934d0bef
Replace traditional `#ifndef`/`#define`/`#endif` include guards with
`#pragma` once.
`#pragma once` is a widely supported preprocessor directive that
prevents header files from being included multiple times. It is
supported by all toolchains used to build edk2: GCC, Clang/LLVM, and
MSVC.
Compared to macro-based include guards, `#pragma once`:
- Eliminates the risk of macro name collisions or copy/paste errors
where two headers inadvertently use the same guard macro.
- Eliminate inconsistency in the way include guard macros are named
(e.g., some files use `__FILE_H__`, others use `FILE_H_`, etc.).
- Reduces boilerplate (three lines replaced by one).
- Avoids polluting the macro namespace with guard symbols.
- Can improve build times as the preprocessor can skip re-opening the
file entirely, rather than re-reading it to find the matching
`#endif` ("multiple-include optimization").
- Note that some compilers may already optimize traditional include
guards, by recognzining the idiomatic pattern.
This change is made acknowledging that overall portability of the
code will technically be reduced, as `#pragma once` is not part of the
C/C++ standards.
However, this is considered acceptable given:
1. edk2 already defines a subset of supported compilers in
BaseTools/Conf/tools_def.template, all of which have supported
`#pragma once` for over two decades.
2. There have been concerns raised to the project about inconsistent
include guard naming and potential macro collisions.
Approximate compiler support dates:
- MSVC: Supported since Visual C++ 4.2 (1996)
- GCC: Supported since 3.4 (2004)
(http://gnu.ist.utl.pt/software/gcc/gcc-3.4/changes.html)
- Clang (LLVM based): Since initial release in 2007
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
58 lines
2 KiB
C
58 lines
2 KiB
C
/** @file
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Define PPI to shadow Firmware Volume from flash to Permanent Memory.
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Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
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SPDX-License-Identifier: BSD-2-Clause-Patent
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**/
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#pragma once
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//
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// Firmware Volume Shadow PPI GUID value
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//
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#define EDKII_FIRMWARE_VOLUME_SHADOW_PPI_GUID \
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{ \
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0x7dfe756c, 0xed8d, 0x4d77, { 0x9e, 0xc4, 0x39, 0x9a, 0x8a, 0x81, 0x51, 0x16 } \
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}
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/**
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Copy FV to Destination. Length of copy is FV length from FV Header.
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@param[in] FirmwareVolumeBase Base address of FV to shadow. Length of FV
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is in FV Header.
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@param[in] Destination Pointer to the Buffer in system memory to
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shadow FV.
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@param[in] DestinationLength Size of Destination buffer in bytes.
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@retval EFI_SUCCESS Shadow complete
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@retval EFI_INVALID_PARAMETER Destination is NULL
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@retval EFI_INVALID_PARAMETER DestinationLength = 0.
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@retval EFI_INVALID_PARAMETER FV does not have valid FV Header.
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@retval EFI_INVALID_PARAMETER FV overlaps Destination.
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@retval EFI_INVALID_PARAMETER Destination + DestinationLength rolls over 4GB
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for 32-bit or 64-bit rollover.
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@retval EFI_BUFFER_TOO_SMALL DestinationLength less than FV length from FV
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Header.
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@retval EFI_UNSUPPORTED FirmwareVolumeBase to FVBase + FVLength does
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not support shadow. Caller should fallback to
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CopyMem().
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**/
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typedef
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EFI_STATUS
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(EFIAPI *EDKII_PEI_FIRMWARE_VOLUME_SHADOW)(
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IN EFI_PHYSICAL_ADDRESS FirmwareVolumeBase,
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IN VOID *Destination,
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IN UINTN DestinationLength
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);
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///
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/// This PPI provides a service to shadow a FV from one location to another
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///
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typedef struct {
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EDKII_PEI_FIRMWARE_VOLUME_SHADOW FirmwareVolumeShadow;
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} EDKII_PEI_FIRMWARE_VOLUME_SHADOW_PPI;
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extern EFI_GUID gEdkiiPeiFirmwareVolumeShadowPpiGuid;
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