AcessNative/ld-acess_src/elf_load.c

   1 /*\r
   2  * Acess v0.1\r
   3  * ELF Executable Loader Code\r
   4  */\r
   5 #define DEBUG   0\r
   6 #include <stdlib.h>\r
   7 #include <stdio.h>\r
   8 #include <string.h>\r
   9 #include <unistd.h>\r
  10 #include "common.h"\r
  11 #include "elf32.h"\r
  12 \r
  13 #define DEBUG_WARN      1\r
  14 \r
  15 #define MKPTR(_type,_val)       ((_type*)(uintptr_t)(_val))\r
  16 #define PTRMK(_type,_val)       MKPTR(_type,_val)\r
  17 #define PTR(_val)       ((void*)(uintptr_t)(_val))\r
  18 \r
  19 #if DEBUG\r
  20 # define ENTER(...)\r
  21 # define LOG(s, ...)    printf("%s: " s, __func__, __VA_ARGS__)\r
  22 # define LOGS(s)        printf("%s: " s, __func__)\r
  23 # define LEAVE(...)\r
  24 #else\r
  25 # define ENTER(...)\r
  26 # define LOG(...)\r
  27 # define LOGS(...)\r
  28 # define LEAVE(...)\r
  29 #endif\r
  30 \r
  31 // === PROTOTYPES ===\r
  32 void    *Elf_Load(int FD);\r
  33 void    *Elf32Load(int FD, Elf32_Ehdr *hdr);\r
  34 \r
  35 // === CODE ===\r
  36 void *Elf_Load(int FD)\r
  37 {\r
  38         Elf32_Ehdr      hdr;\r
  39         \r
  40         // Read ELF Header\r
  41         acess_read(FD, sizeof(hdr), &hdr);\r
  42         \r
  43         // Check the file type\r
  44         if(hdr.e_ident[0] != 0x7F || hdr.e_ident[1] != 'E' || hdr.e_ident[2] != 'L' || hdr.e_ident[3] != 'F') {\r
  45                 Warning("Non-ELF File was passed to the ELF loader\n");\r
  46                 return NULL;\r
  47         }\r
  48 \r
  49         switch(hdr.e_ident[4])\r
  50         {\r
  51         case ELFCLASS32:\r
  52                 return Elf32Load(FD, &hdr);\r
  53         default:\r
  54                 return NULL;\r
  55         }\r
  56 }\r
  57 void *Elf32Load(int FD, Elf32_Ehdr *hdr)\r
  58 {\r
  59         Elf32_Phdr      *phtab;\r
  60          int    i;\r
  61          int    iPageCount;\r
  62         uint32_t        max, base;\r
  63         uint32_t        addr;\r
  64         uint32_t        baseDiff = 0;\r
  65         \r
  66         ENTER("iFD", FD);\r
  67         \r
  68         // Check for a program header\r
  69         if(hdr->phoff == 0) {\r
  70                 #if DEBUG_WARN\r
  71                 Warning("ELF File does not contain a program header\n");\r
  72                 #endif\r
  73                 LEAVE('n');\r
  74                 return NULL;\r
  75         }\r
  76         \r
  77         // Read Program Header Table\r
  78         phtab = malloc( sizeof(Elf32_Phdr) * hdr->phentcount );\r
  79         if( !phtab ) {\r
  80                 LEAVE('n');\r
  81                 return NULL;\r
  82         }\r
  83         LOG("hdr.phoff = 0x%08x\n", hdr->phoff);\r
  84         acess_seek(FD, hdr->phoff, ACESS_SEEK_SET);\r
  85         acess_read(FD, sizeof(Elf32_Phdr) * hdr->phentcount, phtab);\r
  86         \r
  87         // Count Pages\r
  88         iPageCount = 0;\r
  89         LOG("hdr.phentcount = %i\n", hdr->phentcount);\r
  90         for( i = 0; i < hdr->phentcount; i++ )\r
  91         {\r
  92                 // Ignore Non-LOAD types\r
  93                 if(phtab[i].Type != PT_LOAD)\r
  94                         continue;\r
  95                 iPageCount += ((phtab[i].VAddr&0xFFF) + phtab[i].MemSize + 0xFFF) >> 12;\r
  96                 LOG("phtab[%i] = {VAddr:0x%x, MemSize:0x%x}\n", i, phtab[i].VAddr, phtab[i].MemSize);\r
  97         }\r
  98         \r
  99         LOG("iPageCount = %i\n", iPageCount);\r
 100         \r
 101         // Allocate Information Structure\r
 102         //ret = malloc( sizeof(tBinary) + sizeof(tBinaryPage)*iPageCount );\r
 103         // Fill Info Struct\r
 104         //ret->Entry = hdr.entrypoint;\r
 105         //ret->Base = -1;               // Set Base to maximum value\r
 106         //ret->NumPages = iPageCount;\r
 107         //ret->Interpreter = NULL;\r
 108 \r
 109         // Prescan for base and size\r
 110         max = 0;\r
 111         base = 0xFFFFFFFF;\r
 112         for( i = 0; i < hdr->phentcount; i ++)\r
 113         {\r
 114                 if( phtab[i].Type != PT_LOAD )\r
 115                         continue;\r
 116                 if( phtab[i].VAddr < base )\r
 117                         base = phtab[i].VAddr;\r
 118                 if( phtab[i].VAddr + phtab[i].MemSize > max )\r
 119                         max = phtab[i].VAddr + phtab[i].MemSize;\r
 120         }\r
 121 \r
 122         LOG("base = %08x, max = %08x\n", base, max);\r
 123 \r
 124         if( base == 0 ) {\r
 125                 // Find a nice space (31 address bits allowed)\r
 126                 base = FindFreeRange( max, 31 );\r
 127                 LOG("new base = %08x\n", base);\r
 128                 if( base == 0 ) return NULL;\r
 129                 baseDiff = base;\r
 130         }\r
 131         \r
 132         // Load Pages\r
 133         for( i = 0; i < hdr->phentcount; i++ )\r
 134         {\r
 135                 //LOG("phtab[%i].Type = 0x%x", i, phtab[i].Type);\r
 136                 LOG("phtab[%i] = {\n", i);\r
 137                 LOG(" .Type = 0x%08x\n", phtab[i].Type);\r
 138                 LOG(" .Offset = 0x%08x\n", phtab[i].Offset);\r
 139                 LOG(" .VAddr = 0x%08x\n", phtab[i].VAddr);\r
 140                 LOG(" .PAddr = 0x%08x\n", phtab[i].PAddr);\r
 141                 LOG(" .FileSize = 0x%08x\n", phtab[i].FileSize);\r
 142                 LOG(" .MemSize = 0x%08x\n", phtab[i].MemSize);\r
 143                 LOG(" .Flags = 0x%08x\n", phtab[i].Flags);\r
 144                 LOG(" .Align = 0x%08x\n", phtab[i].Align);\r
 145                 LOGS(" }\n");\r
 146                 // Get Interpreter Name\r
 147                 if( phtab[i].Type == PT_INTERP )\r
 148                 {\r
 149                         char *tmp;\r
 150                         //if(ret->Interpreter)  continue;\r
 151                         tmp = malloc(phtab[i].FileSize);\r
 152                         acess_seek(FD, phtab[i].Offset, ACESS_SEEK_SET);\r
 153                         acess_read(FD, phtab[i].FileSize, tmp);\r
 154                         //ret->Interpreter = Binary_RegInterp(tmp);\r
 155                         LOG("Interpreter '%s'\n", tmp);\r
 156                         free(tmp);\r
 157                         continue;\r
 158                 }\r
 159                 // Ignore non-LOAD types\r
 160                 if(phtab[i].Type != PT_LOAD)    continue;\r
 161                 \r
 162                 LOG("phtab[%i] = {VAddr:0x%x,Offset:0x%x,FileSize:0x%x}\n",\r
 163                         i, phtab[i].VAddr+baseDiff, phtab[i].Offset, phtab[i].FileSize);\r
 164                 \r
 165                 addr = phtab[i].VAddr + baseDiff;\r
 166 \r
 167                 if( AllocateMemory( addr, phtab[i].MemSize ) ) {\r
 168                         fprintf(stderr, "Elf_Load: Unable to map memory at %x (0x%x bytes)\n",\r
 169                                 addr, phtab[i].MemSize);\r
 170                         free( phtab );\r
 171                         return NULL;\r
 172                 }\r
 173                 \r
 174                 acess_seek(FD, phtab[i].Offset, ACESS_SEEK_SET);\r
 175                 acess_read(FD, phtab[i].FileSize, PTRMK(void, addr) );\r
 176                 memset( PTRMK(char, addr) + phtab[i].FileSize, 0, phtab[i].MemSize - phtab[i].FileSize );\r
 177         }\r
 178         \r
 179         // Clean Up\r
 180         free(phtab);\r
 181         // Return\r
 182         LEAVE('p', base);\r
 183         return PTRMK(void, base);\r
 184 }\r