Kernel/modules.c

   1 /*
   2  * Acess2
   3  * - Module Loader
   4  */
   5 #include <common.h>
   6 #include <modules.h>
   7
   8 // === PROTOTYPES ===
   9  int    Module_LoadMem(void *Buffer, Uint Length, char *ArgString);
  10  int    Module_LoadFile(char *Path, char *ArgString);
  11  int    Module_int_ResolveDeps(tModule *Info);
  12  int    Module_IsLoaded(char *Name);
  13
  14 // === IMPORTS ===
  15 extern void     StartupPrint(char *Str);
  16 extern tModule  gKernelModules[];
  17 extern void     gKernelModulesEnd;
  18
  19 // === GLOBALS ===
  20  int    giNumBuiltinModules = 0;
  21  int    giModuleSpinlock = 0;
  22 tModule *gLoadedModules = NULL;
  23
  24 // === CODE ===
  25 int Modules_LoadBuiltins()
  26 {
  27          int    i, j, k;
  28          int    numToInit = 0;
  29         Uint8   *baIsLoaded;
  30         char    **deps;
  31
  32         giNumBuiltinModules = (Uint)&gKernelModulesEnd - (Uint)&gKernelModules;
  33         giNumBuiltinModules /= sizeof(tModule);
  34
  35         baIsLoaded = calloc( giNumBuiltinModules, sizeof(*baIsLoaded) );
  36
  37         // Pass 1 - Are the dependencies compiled in?
  38         for( i = 0; i < giNumBuiltinModules; i++ )
  39         {
  40                 deps = gKernelModules[i].Dependencies;
  41                 if(deps)
  42                 {
  43                         for( j = 0; deps[j]; j++ )
  44                         {
  45                                 for( k = 0; k < giNumBuiltinModules; k++ ) {
  46                                         if(strcmp(deps[j], gKernelModules[k].Name) == 0)
  47                                                 break;
  48                                 }
  49                                 if(k == giNumBuiltinModules) {
  50                                         Warning("Unable to find dependency '%s' for '%s' in kernel",
  51                                                 deps[j], gKernelModules[i].Name);
  52
  53                                         baIsLoaded[i] = -1;     // Don't Load
  54                                         break;
  55                                 }
  56                         }
  57                 }
  58                 numToInit ++;
  59         }
  60
  61         // Pass 2 - Intialise
  62         while(numToInit)
  63         {
  64                 for( i = 0; i < giNumBuiltinModules; i++ )
  65                 {
  66                         if( baIsLoaded[i] )     continue;       // Ignore already loaded modules
  67
  68                         if( deps )
  69                         {
  70                                 for( j = 0; deps[j]; j++ )
  71                                 {
  72                                         for( k = 0; k < giNumBuiltinModules; k++ ) {
  73                                                 if(strcmp(deps[j], gKernelModules[k].Name) == 0)
  74                                                         break;
  75                                         }
  76                                         // `k` is assumed to be less than `giNumBuiltinModules`
  77
  78                                         // If a dependency failed, skip and mark as failed
  79                                         if( baIsLoaded[k] == -1 ) {
  80                                                 baIsLoaded[i] = -1;
  81                                                 numToInit --;
  82                                                 break;
  83                                         }
  84                                         // If a dependency is not intialised, skip
  85                                         if( !baIsLoaded[k] )    break;
  86                                 }
  87                                 // Check if we broke out
  88                                 if( deps[j] )   continue;
  89                         }
  90
  91                         // All Dependencies OK? Initialise
  92                         StartupPrint(gKernelModules[i].Name);
  93                         Log("Initialising %p '%s' v%i.%i...",
  94                                 &gKernelModules[i],
  95                                 gKernelModules[i].Name,
  96                                 gKernelModules[i].Version>>8, gKernelModules[i].Version & 0xFF
  97                                 );
  98                         gKernelModules[i].Init(NULL);
  99                         // Mark as loaded
 100                         baIsLoaded[i] = 1;
 101                         numToInit --;
 102                 }
 103         }
 104
 105         return 0;
 106 }
 107
 108 /**
 109  * \fn int Module_LoadMem(void *Buffer, Uint Length, char *ArgString)
 110  * \brief Load a module from a memory location
 111  */
 112 int Module_LoadMem(void *Buffer, Uint Length, char *ArgString)
 113 {
 114         char    path[VFS_MEMPATH_SIZE];
 115
 116         VFS_GetMemPath(Buffer, Length, path);
 117
 118         return Module_LoadFile( path, ArgString );
 119 }
 120
 121 /**
 122  * \fn int Module_LoadFile(char *Path, char *ArgString)
 123  * \brief Load a module from a file
 124  */
 125 int Module_LoadFile(char *Path, char *ArgString)
 126 {
 127         void    *base;
 128         tModule *info;
 129
 130         // Load Binary
 131         base = Binary_LoadKernel(Path);
 132
 133         // Error check
 134         if(base == NULL)        return 0;
 135
 136         // Check for Acess Driver
 137         if( Binary_FindSymbol(base, "DriverInfo", (Uint*)&info ) == 0 )
 138         {
 139                 #if USE_EDI
 140                 // Check for EDI Driver
 141                 if( Binary_FindSymbol(base, "driver_init", NULL ) == 0 )
 142                 {
 143                         Binary_Relocate(base);  // Relocate
 144                         return Module_InitEDI( base );  // And intialise
 145                 }
 146                 #endif
 147
 148                 // Unknown module type?, return error
 149                 Binary_Unload(base);
 150                 #if USE_EDI
 151                 Warning("Module_LoadMem: Module has neither a Module Info struct, nor an EDI entrypoint");
 152                 #else
 153                 Warning("Module_LoadMem: Module does not have a Module Info struct");
 154                 #endif
 155                 return 0;
 156         }
 157
 158         // Check magic number
 159         if(info->Magic != MODULE_MAGIC)
 160         {
 161                 Warning("Module_LoadMem: Module's magic value is invalid (0x%x != 0x%x)", info->Magic, MODULE_MAGIC);
 162                 return 0;
 163         }
 164
 165         // Check Architecture
 166         if(info->Arch != MODULE_ARCH_ID)
 167         {
 168                 Warning("Module_LoadMem: Module is for a different architecture");
 169                 return 0;
 170         }
 171
 172         // Resolve Dependencies
 173         if( !Module_int_ResolveDeps(info) ) {
 174                 Binary_Unload(base);
 175                 return 0;
 176         }
 177
 178         // Call Initialiser
 179         //if( info->Init( ArgString ) != 0 )
 180         if( info->Init( NULL ) == 0 )
 181         {
 182                 Binary_Unload(base);
 183                 return 0;
 184         }
 185
 186         // Add to list
 187         LOCK( &giModuleSpinlock );
 188         info->Next = gLoadedModules;
 189         gLoadedModules = info;
 190         RELEASE( &giModuleSpinlock );
 191
 192         return 1;
 193 }
 194
 195 /**
 196  * \fn int Module_int_ResolveDeps(tModule *Info)
 197  * \brief Resolves the dependencies
 198  * \todo Implement
 199  * \note Currently does not resolve the dependencies, just checks them
 200  */
 201 int Module_int_ResolveDeps(tModule *Info)
 202 {
 203         char    **names = Info->Dependencies;
 204
 205         // Walk dependencies array
 206         for( ; *names; names++ )
 207         {
 208                 // Check if the module is loaded
 209                 if( !Module_IsLoaded(*names) ) {
 210                         Warning("Module `%s' requires `%s', which is not loaded\n", Info->Name, *names);
 211                         return 0;
 212                 }
 213         }
 214         return 1;
 215 }
 216
 217 /**
 218  * \fn int Module_IsLoaded(char *Name)
 219  * \brief Checks if a module is loaded
 220  * \param Name  Name of module to find
 221  */
 222 int Module_IsLoaded(char *Name)
 223 {
 224         tModule *mod = gLoadedModules;
 225
 226         // Scan loaded list
 227         for( ; mod; mod = mod->Next )
 228         {
 229                 // If found, return true
 230                 if(strcmp(mod->Name, Name) == 0)
 231                         return 1;
 232         }
 233         // not found - return false
 234         return 0;
 235 }