From 96cf66ac354aa350a11a72a75f4feabe54b509fd Mon Sep 17 00:00:00 2001
From: Timo Kreuzer <timo.kreuzer@reactos.org>
Date: Tue, 7 Jun 2011 22:45:56 +0000
Subject: [PATCH] [OBJ2BIN] - Implement coff relocation

svn path=/trunk/; revision=52141
---
 reactos/tools/obj2bin/obj2bin.c | 98 +++++++++++++++++++++++++++++++--
 reactos/tools/pecoff.h          | 34 ++++++++++++
 2 files changed, 126 insertions(+), 6 deletions(-)

diff --git a/reactos/tools/obj2bin/obj2bin.c b/reactos/tools/obj2bin/obj2bin.c
index 8f71cf55e15..97cad423235 100644
--- a/reactos/tools/obj2bin/obj2bin.c
+++ b/reactos/tools/obj2bin/obj2bin.c
@@ -11,18 +11,54 @@ Usage(void)
            "Syntax: obj2bin <source file> <dest file>\n");
 }
 
+static
+void
+RelocateImage(
+    char *pData,
+    PIMAGE_RELOCATION pReloc,
+    unsigned int cNumRelocs,
+    PIMAGE_SYMBOL pSymbols,
+    unsigned int iOffset)
+{
+    unsigned int i;
+    WORD *p16;
+
+    for (i = 0; i < cNumRelocs; i++)
+    {
+        switch (pReloc->Type)
+        {
+            case IMAGE_REL_I386_ABSOLUTE:
+                p16 = (void*)(pData + pReloc->VirtualAddress);
+                *p16 = (WORD)(pSymbols[pReloc->SymbolTableIndex].Value + iOffset);
+                break;
+
+            default:
+                printf("Unknown relocatation type %ld\n", pReloc->Type);
+        }
+
+        pReloc++;
+    }
+}
+
 int main(int argc, char *argv[])
 {
     char *pszSourceFile;
     char *pszDestFile;
+    unsigned long iOffset;
     FILE *pSourceFile, *pDestFile;
     IMAGE_FILE_HEADER FileHeader;
     IMAGE_SECTION_HEADER SectionHeader;
     unsigned int i;
     size_t nSize;
     void *pData;
+    PIMAGE_RELOCATION pReloc;
+    PIMAGE_SYMBOL pSymbols;
 
-    if ((argc != 3) || (strcmp(argv[1], "--help") == 0)) Usage();
+    if ((argc != 4) || (strcmp(argv[1], "--help") == 0))
+    {
+        Usage();
+        return -1;
+    }
 
     pszSourceFile = argv[1];
     pszDestFile = argv[2];
@@ -41,6 +77,8 @@ int main(int argc, char *argv[])
         return -2;
     }
 
+    iOffset = strtol(argv[3], 0, 16);
+
     /* Load the coff header */
     nSize = fread(&FileHeader, 1, sizeof(FileHeader), pSourceFile);
     if (nSize != sizeof(FileHeader))
@@ -77,33 +115,81 @@ int main(int argc, char *argv[])
         return -6;
     }
 
-    /* Move file pointer to the start of the section*/
-    if (fseek(pSourceFile, SectionHeader.PointerToRawData, SEEK_SET))
+    /* Move file pointer to the symbol table */
+    if (fseek(pSourceFile, FileHeader.PointerToSymbolTable, SEEK_SET))
     {
         fprintf(stderr, "Failed to set file pointer\n");
         return -7;
     }
 
+    /* Allocate memory for the symbols */
+    nSize = FileHeader.NumberOfSymbols * sizeof(IMAGE_SYMBOL);
+    pSymbols = malloc(nSize);
+    if (!pSymbols)
+    {
+        fprintf(stderr, "Failed to allocate %ld bytes\n", nSize);
+        return -8;
+    }
+
+    /* Read symbol data */
+    if (!fread(pSymbols, nSize, 1, pSourceFile))
+    {
+        fprintf(stderr, "Failed to read section %ld file\n", i);
+        return -9;
+    }
+
+    /* Move file pointer to the start of the section */
+    if (fseek(pSourceFile, SectionHeader.PointerToRawData, SEEK_SET))
+    {
+        fprintf(stderr, "Failed to set file pointer\n");
+        return -10;
+    }
+
     /* Allocate memory for the section */
     pData = malloc(SectionHeader.SizeOfRawData);
     if (!pData)
     {
         fprintf(stderr, "Failed to allocate %ld bytes\n", SectionHeader.SizeOfRawData);
-        return -8;
+        return -11;
     }
 
     /* Read section data */
     if (!fread(pData, SectionHeader.SizeOfRawData, 1, pSourceFile))
     {
         fprintf(stderr, "Failed to read section %ld file\n", i);
-        return -5;
+        return -12;
     }
 
+    /* Allocate memory for the relocation */
+    nSize = SectionHeader.NumberOfRelocations * sizeof(IMAGE_RELOCATION);
+    pReloc = malloc(nSize);
+    if (!pReloc)
+    {
+        fprintf(stderr, "Failed to allocate %ld bytes\n", nSize);
+        return -13;
+    }
+
+    /* Move file pointer to the relocation table */
+    if (fseek(pSourceFile, SectionHeader.PointerToRelocations, SEEK_SET))
+    {
+        fprintf(stderr, "Failed to set file pointer\n");
+        return -14;
+    }
+
+    /* Read relocation data */
+    if (!fread(pReloc, nSize, 1, pSourceFile))
+    {
+        fprintf(stderr, "Failed to read section %ld file\n", i);
+        return -15;
+    }
+
+    RelocateImage(pData, pReloc, SectionHeader.NumberOfRelocations, pSymbols, iOffset);
+
     /* Write the section to the destination file */
     if (!fwrite(pData, SectionHeader.SizeOfRawData, 1, pDestFile))
     {
         fprintf(stderr, "Failed to write data\n");
-        return -9;
+        return -16;
     }
 
     fclose(pDestFile);
diff --git a/reactos/tools/pecoff.h b/reactos/tools/pecoff.h
index d3a32502c09..288255a8835 100644
--- a/reactos/tools/pecoff.h
+++ b/reactos/tools/pecoff.h
@@ -41,11 +41,15 @@
 
 #define IMAGE_NUMBEROF_DIRECTORY_ENTRIES 16
 
+#define IMAGE_REL_I386_ABSOLUTE 0x0001
+
 typedef unsigned char BYTE;
 typedef unsigned char UCHAR;
 typedef unsigned short WORD;
+typedef short SHORT;
 typedef unsigned short USHORT;
 typedef unsigned long long ULONGLONG;
+
 #if defined(__x86_64__) && !defined(_WIN64)
 typedef signed int LONG;
 typedef unsigned int ULONG;
@@ -205,3 +209,33 @@ typedef struct _IMAGE_BASE_RELOCATION {
 } IMAGE_BASE_RELOCATION,*PIMAGE_BASE_RELOCATION;
 #pragma pack(pop)
 
+#pragma pack(push,2)
+typedef struct _IMAGE_RELOCATION {
+  union {
+    DWORD VirtualAddress;
+    DWORD RelocCount;
+  };
+  DWORD SymbolTableIndex;
+  WORD Type;
+} IMAGE_RELOCATION;
+typedef struct _IMAGE_RELOCATION UNALIGNED *PIMAGE_RELOCATION;
+#pragma pack(pop)
+
+#pragma pack(push,2)
+typedef struct _IMAGE_SYMBOL {
+  union {
+    BYTE ShortName[8];
+    struct {
+      DWORD Short;
+      DWORD Long;
+    } Name;
+    DWORD LongName[2];
+  } N;
+  DWORD Value;
+  SHORT SectionNumber;
+  WORD Type;
+  BYTE StorageClass;
+  BYTE NumberOfAuxSymbols;
+} IMAGE_SYMBOL;
+typedef struct _IMAGE_SYMBOL UNALIGNED *PIMAGE_SYMBOL;
+#pragma pack(pop)