Add AllocateSmbiosRecord() to SmbiosStringTableLib to encapsulate the
SMBIOS spec Section 6.1.3 string-area termination rule. Callers pass
the fixed structure size and an optional string table; the function
appends the correct string area (two-byte double-NULL when no strings
are present, or the full string set size from
StringTableGetStringSetSize() when strings exist).
This removes the need for each generator to open-code the double-NULL
or manually compute the string area size.
Signed-off-by: Girish Mahadevan <gmahadevan@nvidia.com>
Signed-off-by: Varshit Pandya <varshit.pandya@arm.com>
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>
The Section 6.1.3, SMBIOS specification version 3.6.0 describes the
handling of test strings in SMBIOS tables.
Text strings are added at the end of the formatted portion of the SMBIOS
structure and are referenced by index in the SMBIOS structure.
Therefore, introduce a SmbiosStringTableLib to simplify the publishing
of the string set.
SmbiosStringTableLib introduces a concept of string table which records
the references to the SMBIOS strings as they are added and returns an
string reference which is then assigned to the string field in the
formatted portion of the SMBIOS structure. Once all strings are added,
the library provides an interface to get the required size for the string
set. This allows sufficient memory to be allocated for the SMBIOS table.
The library also provides an interface to publish the string set in
accordance with the SMBIOS specification.
Example:
EFI_STATUS
BuildSmbiosType17Table () {
STRING_TABLE StrTable;
UINT8 DevLocatorRef;
UINT8 BankLocatorRef;
SMBIOS_TABLE_TYPE17 *SmbiosRecord;
CHAR8 *StringSet;
...
// Initialize string table for 7 strings
StringTableInitialize (&StrTable, 7);
StringTableAddString (&StrTable, "SIMM 3", &DevLocatorRef);
StringTableAddString (&StrTable, "Bank 0", &BankLocatorRef);
...
SmbiosRecord = AllocateZeroPool (
sizeof (SMBIOS_TABLE_TYPE17) +
StringTableGetStringSetSize (&StrTable)
);
...
SmbiosRecord->DeviceLocator = DevLocatorRef;
SmbiosRecord->BankLocator = BankLocatorRef;
...
// get the string set area
StringSet = (CHAR8*)(SmbiosRecord + 1);
// publish the string set
StringTablePublishStringSet (
&StrTable,
StringSet,
StringTableGetStringSetSize (&StrTable)
);
// free string table
StringTableFree (&StrTable);
return EFI_SUCCESS;
}
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>
Cc: Alexei Fedorov <Alexei.Fedorov@arm.com>
Cc: Pierre Gondois <pierre.gondois@arm.com>
Cc: Girish Mahadevan <gmahadevan@nvidia.com>
Cc: Jeff Brasen <jbrasen@nvidia.com>
Cc: Ashish Singhal <ashishsingha@nvidia.com>
Cc: Nick Ramirez <nramirez@nvidia.com>
Cc: William Watson <wwatson@nvidia.com>
Cc: Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud@arm.com>
