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BaseTools: Add --export-symbol option to GenFw for explicit symbol exports #1621

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BaseTools: Add --export-symbol option to GenFw for explicit symbol exports #1621

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151 changes: 119 additions & 32 deletions BaseTools/Source/C/GenFw/Elf64Convert.c
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Original file line number Diff line number Diff line change
Expand Up @@ -190,7 +190,7 @@ InitializeElf64 (

if (mExportFlag) {
if ((mEhdr->e_machine != EM_X86_64) && (mEhdr->e_machine != EM_AARCH64)) {
Error (NULL, 0, 3000, "Unsupported", "--prm option currently only supports X64 and AArch64 archs.");
Error (NULL, 0, 3000, "Unsupported", "--prm/--export-symbol option currently only supports X64 and AArch64 archs.");
return FALSE;
}
}
Expand Down Expand Up @@ -1038,9 +1038,14 @@ ScanSections64 (
//
if (mExportFlag) {
UINT32 SymIndex;
UINT32 ExpIndex;
UINT32 j;
Elf_Sym *Sym;
UINT64 SymNum;
const UINT8 *SymName;
BOOLEAN Found;
UINT8 *Symtab;
Elf_Shdr *shdr;

mExportOffset = mCoffOffset;
mExportSize = sizeof(EFI_IMAGE_EXPORT_DIRECTORY) + strlen(mInImageName) + 1;
Expand All @@ -1050,59 +1055,141 @@ ScanSections64 (
//
// Determine if this is a symbol section.
//
Elf_Shdr *shdr = GetShdrByIndex(i);
shdr = GetShdrByIndex(i);
if (!IsSymbolShdr(shdr)) {
continue;
}

UINT8 *Symtab = (UINT8*)mEhdr + shdr->sh_offset;
Symtab = (UINT8*)mEhdr + shdr->sh_offset;
SymNum = (shdr->sh_size) / (shdr->sh_entsize);

//
// First Get PrmModuleExportDescriptor
// Check if we have explicit export symbols specified via --export-symbol
//
for (SymIndex = 0; SymIndex < SymNum; SymIndex++) {
Sym = (Elf_Sym *)(Symtab + SymIndex * shdr->sh_entsize);
SymName = GetSymName(Sym);
if (SymName == NULL) {
if (mExplicitExportSymbolCount > 0) {
//
// Use explicit export symbols instead of PRM mechanism
//
for (SymIndex = 0; SymIndex < SymNum; SymIndex++) {
Sym = (Elf_Sym *)(Symtab + SymIndex * shdr->sh_entsize);
SymName = GetSymName(Sym);
if (SymName == NULL) {
continue;
}
}

if (strcmp((CHAR8*)SymName, PRM_MODULE_EXPORT_DESCRIPTOR_NAME) == 0) {
//
// Find PrmHandler Number and Name
// Check if this symbol matches any of our explicit export symbols
//
FindPrmHandler(Sym->st_value);
for (ExpIndex = 0; ExpIndex < mExplicitExportSymbolCount; ExpIndex++) {
if (strcmp((CHAR8*)SymName, mExplicitExportSymbols[ExpIndex]) == 0) {
//
// Check if we already added this symbol (handles multiple symbol sections)
//
Found = FALSE;
for (j = 0; j < mExportSymNum; j++) {
if (strcmp(mExportSymName[j], (CHAR8*)SymName) == 0) {
Found = TRUE;
break;
}
}
if (Found) {
break;
}

//
// Found a matching symbol - add it to exports.
// Note: Symbol names are limited to PRM_HANDLER_NAME_MAXIMUM_LENGTH (128 chars)
// as we reuse the PRM export infrastructure (mExportSymName array).
//
strncpy(mExportSymName[mExportSymNum], (CHAR8*)SymName, PRM_HANDLER_NAME_MAXIMUM_LENGTH - 1);
mExportSymName[mExportSymNum][PRM_HANDLER_NAME_MAXIMUM_LENGTH - 1] = '\0';
mExportRVA[mExportSymNum] = (UINT32)(Sym->st_value);
mExportSize += 2 * EFI_IMAGE_EXPORT_ADDR_SIZE + EFI_IMAGE_EXPORT_ORDINAL_SIZE + strlen((CHAR8 *)SymName) + 1;
mExportSymNum++;

if (mExportSymNum >= PRM_MODULE_EXPORT_SYMBOL_NUM) {
Error (NULL, 0, 3000, "Invalid", "Too many export symbols (max %d).", PRM_MODULE_EXPORT_SYMBOL_NUM);
return FALSE;
}
break;
}
}
}

strcpy(mExportSymName[mExportSymNum], (CHAR8*)SymName);
mExportRVA[mExportSymNum] = (UINT32)(Sym->st_value);
mExportSize += 2 * EFI_IMAGE_EXPORT_ADDR_SIZE + EFI_IMAGE_EXPORT_ORDINAL_SIZE + strlen((CHAR8 *)SymName) + 1;
mExportSymNum ++;
//
// Check if we found all requested symbols
//
if (mExportSymNum == mExplicitExportSymbolCount) {
//
// All symbols found, exit the section loop
//
break;
}
}
} else {
//
// Use PRM mechanism - First Get PrmModuleExportDescriptor
//
for (SymIndex = 0; SymIndex < SymNum; SymIndex++) {
Sym = (Elf_Sym *)(Symtab + SymIndex * shdr->sh_entsize);
SymName = GetSymName(Sym);
if (SymName == NULL) {
continue;
}

//
// Second Get PrmHandler
//
for (SymIndex = 0; SymIndex < SymNum; SymIndex++) {
UINT32 ExpIndex;
Sym = (Elf_Sym *)(Symtab + SymIndex * shdr->sh_entsize);
SymName = GetSymName(Sym);
if (SymName == NULL) {
continue;
if (strcmp((CHAR8*)SymName, PRM_MODULE_EXPORT_DESCRIPTOR_NAME) == 0) {
//
// Find PrmHandler Number and Name
//
FindPrmHandler(Sym->st_value);

strcpy(mExportSymName[mExportSymNum], (CHAR8*)SymName);
mExportRVA[mExportSymNum] = (UINT32)(Sym->st_value);
mExportSize += 2 * EFI_IMAGE_EXPORT_ADDR_SIZE + EFI_IMAGE_EXPORT_ORDINAL_SIZE + strlen((CHAR8 *)SymName) + 1;
mExportSymNum ++;
break;
}
}

for (ExpIndex = 0; ExpIndex < (mExportSymNum -1); ExpIndex++) {
if (strcmp((CHAR8*)SymName, mExportSymName[ExpIndex]) != 0) {
continue;
//
// Second Get PrmHandler
//
for (SymIndex = 0; SymIndex < SymNum; SymIndex++) {
Sym = (Elf_Sym *)(Symtab + SymIndex * shdr->sh_entsize);
SymName = GetSymName(Sym);
if (SymName == NULL) {
continue;
}

for (ExpIndex = 0; ExpIndex < (mExportSymNum -1); ExpIndex++) {
if (strcmp((CHAR8*)SymName, mExportSymName[ExpIndex]) != 0) {
continue;
}
mExportRVA[ExpIndex] = (UINT32)(Sym->st_value);
mExportSize += 2 * EFI_IMAGE_EXPORT_ADDR_SIZE + EFI_IMAGE_EXPORT_ORDINAL_SIZE + strlen((CHAR8 *)SymName) + 1;
}
mExportRVA[ExpIndex] = (UINT32)(Sym->st_value);
mExportSize += 2 * EFI_IMAGE_EXPORT_ADDR_SIZE + EFI_IMAGE_EXPORT_ORDINAL_SIZE + strlen((CHAR8 *)SymName) + 1;
}

break;
}
}

break;
//
// Verify all requested symbols were found (for explicit export mode)
//
if ((mExplicitExportSymbolCount > 0) && (mExportSymNum != mExplicitExportSymbolCount)) {
for (ExpIndex = 0; ExpIndex < mExplicitExportSymbolCount; ExpIndex++) {
Found = FALSE;
for (j = 0; j < mExportSymNum; j++) {
if (strcmp(mExplicitExportSymbols[ExpIndex], mExportSymName[j]) == 0) {
Found = TRUE;
break;
}
}
if (!Found) {
Error (NULL, 0, 3000, "Invalid", "Symbol '%s' not found in ELF file.", mExplicitExportSymbols[ExpIndex]);
}
}
return FALSE;
}

mCoffOffset += mExportSize;
Expand Down
2 changes: 2 additions & 0 deletions BaseTools/Source/C/GenFw/ElfConvert.h
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Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,8 @@ extern UINT32 mOutImageType;
extern UINT32 mFileBufferSize;
extern BOOLEAN mExportFlag;
extern BOOLEAN mBuildIdFlag;
extern UINT32 mExplicitExportSymbolCount;
extern CHAR8 *mExplicitExportSymbols[];

//
// Common EFI specific data.
Expand Down
30 changes: 30 additions & 0 deletions BaseTools/Source/C/GenFw/GenFw.c
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Original file line number Diff line number Diff line change
Expand Up @@ -39,6 +39,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
#include "EfiUtilityMsgs.h"

#include "GenFw.h"
#include "ElfConvert.h"

//
// Version of this utility
Expand Down Expand Up @@ -91,6 +92,12 @@ BOOLEAN mExportFlag = FALSE;
BOOLEAN mNoNxCompat = FALSE;
BOOLEAN mBuildIdFlag = FALSE;

//
// Explicit export symbol support
//
UINT32 mExplicitExportSymbolCount = 0;
CHAR8 *mExplicitExportSymbols[PRM_MODULE_EXPORT_SYMBOL_NUM];

STATIC
EFI_STATUS
ZeroDebugData (
Expand Down Expand Up @@ -285,6 +292,10 @@ Routine Description:
write export table into PE-COFF.\n\
This option can be used together with -e.\n\
It doesn't work for other options.\n");
fprintf (stdout, " --export-symbol=NAME Export the specified symbol to PE-COFF export table.\n\
Can be specified multiple times for multiple symbols.\n\
This option can be used together with -e.\n\
It doesn't work for other options.\n");
fprintf (stdout, " --nonxcompat Do not set the IMAGE_DLLCHARACTERISTICS_NX_COMPAT bit \n\
of the optional header in the PE header even if the \n\
requirements are met.\n");
Expand Down Expand Up @@ -1516,6 +1527,25 @@ Routine Description:
continue;
}

if (strnicmp (argv[0], "--export-symbol=", 16) == 0) {
if (mExplicitExportSymbolCount >= PRM_MODULE_EXPORT_SYMBOL_NUM) {
Error (NULL, 0, 1003, "Invalid option", "Too many --export-symbol options (max %d)", PRM_MODULE_EXPORT_SYMBOL_NUM);
goto Finish;
}
mExplicitExportSymbols[mExplicitExportSymbolCount] = argv[0] + 16;
if (strlen(mExplicitExportSymbols[mExplicitExportSymbolCount]) == 0) {
Error (NULL, 0, 1003, "Invalid option value", "--export-symbol requires a symbol name");
goto Finish;
}
mExplicitExportSymbolCount++;
if (!mExportFlag) {
mExportFlag = TRUE;
}
argc --;
argv ++;
continue;
}

if (stricmp (argv[0], "--nonxcompat") == 0) {
mNoNxCompat = TRUE;
argc --;
Expand Down
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