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                                 Log("%s requires %s\n", gKernelModules[i].Name, deps[j]);
  50                                 if(k == giNumBuiltinModules) {
  51                                         Warning("Unable to find dependency '%s' for '%s' in kernel",
  52                                                 deps[j], gKernelModules[i].Name);
  53
  54                                         baIsLoaded[i] = -1;     // Don't Load
  55                                         break;
  56                                 }
  57                         }
  58                 }
  59                 numToInit ++;
  60         }
  61
  62         // Pass 2 - Intialise
  63         while(numToInit)
  64         {
  65                 for( i = 0; i < giNumBuiltinModules; i++ )
  66                 {
  67                         if( baIsLoaded[i] )     continue;       // Ignore already loaded modules
  68
  69                         deps = gKernelModules[i].Dependencies;
  70
  71                         if( deps )
  72                         {
  73                                 for( j = 0; deps[j]; j++ )
  74                                 {
  75                                         for( k = 0; k < giNumBuiltinModules; k++ ) {
  76                                                 if(strcmp(deps[j], gKernelModules[k].Name) == 0)
  77                                                         break;
  78                                         }
  79                                         // `k` is assumed to be less than `giNumBuiltinModules`
  80
  81                                         Log("baIsLoaded[%i(%s)] = %i\n", k, deps[j], baIsLoaded[k]);
  82                                         // If a dependency failed, skip and mark as failed
  83                                         if( baIsLoaded[k] == -1 ) {
  84                                                 baIsLoaded[i] = -1;
  85                                                 numToInit --;
  86                                                 break;
  87                                         }
  88                                         // If a dependency is not intialised, skip
  89                                         if( !baIsLoaded[k] )    break;
  90                                 }
  91                                 // Check if we broke out
  92                                 if( deps[j] )   continue;
  93                         }
  94
  95                         // All Dependencies OK? Initialise
  96                         StartupPrint(gKernelModules[i].Name);
  97                         Log("Initialising %p '%s' v%i.%i...",
  98                                 &gKernelModules[i],
  99                                 gKernelModules[i].Name,
 100                                 gKernelModules[i].Version>>8, gKernelModules[i].Version & 0xFF
 101                                 );
 102                         gKernelModules[i].Init(NULL);
 103                         // Mark as loaded
 104                         baIsLoaded[i] = 1;
 105                         numToInit --;
 106                 }
 107         }
 108
 109         return 0;
 110 }
 111
 112 /**
 113  * \fn int Module_LoadMem(void *Buffer, Uint Length, char *ArgString)
 114  * \brief Load a module from a memory location
 115  */
 116 int Module_LoadMem(void *Buffer, Uint Length, char *ArgString)
 117 {
 118         char    path[VFS_MEMPATH_SIZE];
 119
 120         VFS_GetMemPath(Buffer, Length, path);
 121
 122         return Module_LoadFile( path, ArgString );
 123 }
 124
 125 /**
 126  * \fn int Module_LoadFile(char *Path, char *ArgString)
 127  * \brief Load a module from a file
 128  */
 129 int Module_LoadFile(char *Path, char *ArgString)
 130 {
 131         void    *base;
 132         tModule *info;
 133
 134         // Load Binary
 135         base = Binary_LoadKernel(Path);
 136
 137         // Error check
 138         if(base == NULL)        return 0;
 139
 140         // Check for Acess Driver
 141         if( Binary_FindSymbol(base, "DriverInfo", (Uint*)&info ) == 0 )
 142         {
 143                 #if USE_EDI
 144                 // Check for EDI Driver
 145                 if( Binary_FindSymbol(base, "driver_init", NULL ) == 0 )
 146                 {
 147                         Binary_Relocate(base);  // Relocate
 148                         return Module_InitEDI( base );  // And intialise
 149                 }
 150                 #endif
 151
 152                 // Unknown module type?, return error
 153                 Binary_Unload(base);
 154                 #if USE_EDI
 155                 Warning("Module_LoadMem: Module has neither a Module Info struct, nor an EDI entrypoint");
 156                 #else
 157                 Warning("Module_LoadMem: Module does not have a Module Info struct");
 158                 #endif
 159                 return 0;
 160         }
 161
 162         // Check magic number
 163         if(info->Magic != MODULE_MAGIC)
 164         {
 165                 Warning("Module_LoadMem: Module's magic value is invalid (0x%x != 0x%x)", info->Magic, MODULE_MAGIC);
 166                 return 0;
 167         }
 168
 169         // Check Architecture
 170         if(info->Arch != MODULE_ARCH_ID)
 171         {
 172                 Warning("Module_LoadMem: Module is for a different architecture");
 173                 return 0;
 174         }
 175
 176         // Resolve Dependencies
 177         if( !Module_int_ResolveDeps(info) ) {
 178                 Binary_Unload(base);
 179                 return 0;
 180         }
 181
 182         Log("Initialising %p '%s' v%i.%i...",
 183                                 info,
 184                                 info->Name,
 185                                 info->Version>>8, info->Version & 0xFF
 186                                 );
 187
 188         // Call Initialiser
 189         //if( info->Init( ArgString ) != 0 )
 190         if( info->Init( NULL ) == 0 )
 191         {
 192                 Binary_Unload(base);
 193                 return 0;
 194         }
 195
 196         // Add to list
 197         LOCK( &giModuleSpinlock );
 198         info->Next = gLoadedModules;
 199         gLoadedModules = info;
 200         RELEASE( &giModuleSpinlock );
 201
 202         return 1;
 203 }
 204
 205 /**
 206  * \fn int Module_int_ResolveDeps(tModule *Info)
 207  * \brief Resolves the dependencies
 208  * \todo Implement
 209  * \note Currently does not resolve the dependencies, just checks them
 210  */
 211 int Module_int_ResolveDeps(tModule *Info)
 212 {
 213         char    **names = Info->Dependencies;
 214
 215         // Walk dependencies array
 216         for( ; *names; names++ )
 217         {
 218                 // Check if the module is loaded
 219                 if( !Module_IsLoaded(*names) ) {
 220                         Warning("Module `%s' requires `%s', which is not loaded\n", Info->Name, *names);
 221                         return 0;
 222                 }
 223         }
 224         return 1;
 225 }
 226
 227 /**
 228  * \fn int Module_IsLoaded(char *Name)
 229  * \brief Checks if a module is loaded
 230  * \param Name  Name of module to find
 231  */
 232 int Module_IsLoaded(char *Name)
 233 {
 234         tModule *mod = gLoadedModules;
 235
 236         // Scan loaded list
 237         for( ; mod; mod = mod->Next )
 238         {
 239                 // If found, return true
 240                 if(strcmp(mod->Name, Name) == 0)
 241                         return 1;
 242         }
 243         // not found - return false
 244         return 0;
 245 }