qemu/roms/openbios/arch/unix/plugins/loader.c

   1 /* tag: openbios plugin loader
   2  *
   3  * Copyright (C) 2003 Stefan Reinauer
   4  *
   5  * See the file "COPYING" for further information about
   6  * the copyright and warranty status of this work.
   7  */
   8
   9 /* This is a simple plugin loader. OpenBIOS duplicates some
  10  * of this code in kernel/arch/unix/plugins.c. This code is
  11  * here for reference and simple testing.
  12  */
  13
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17 #include <dlfcn.h>
  18 #include <unistd.h>             // sleep
  19
  20 #include "unix/plugins.h"
  21
  22 #define PLUGINDIR  "/usr/share/OpenBIOS/plugins"
  23 #define PATHSIZE   256
  24
  25 #define DEBUG_PLUGINS
  26
  27 typedef struct iorange iorange_t;
  28 struct iorange {
  29         const char *name;
  30         unsigned int start;
  31         unsigned int end;
  32         io_ops_t *ops;
  33         iorange_t *next;
  34 };
  35
  36 iorange_t *ioranges = NULL;
  37
  38 typedef struct plugin plugin_t;
  39 struct plugin {
  40         const char *name;
  41         plugin_t *next;
  42 };
  43
  44 plugin_t *plugins = NULL;
  45
  46 int register_iorange(const char *name, io_ops_t * ops, unsigned int rstart,
  47                      unsigned int rend)
  48 {
  49         iorange_t *newrange;
  50
  51         /* intersection check */
  52         newrange = ioranges;
  53         while (newrange) {
  54                 int fail = 0;
  55                 /* new section swallows old section */
  56                 if (newrange->start >= rstart && newrange->end <= rend)
  57                         fail = -1;
  58                 /* new section start or end point are within range */
  59                 if (newrange->start <= rstart && newrange->end >= rstart)
  60                         fail = -1;
  61                 if (newrange->start <= rend && newrange->end >= rend)
  62                         fail = -1;
  63                 if (fail) {
  64                         printf("Error: overlapping IO regions: %s and %s\n",
  65                              newrange->name, name);
  66                         return -1;
  67                 }
  68                 newrange = newrange->next;
  69         }
  70
  71         newrange = malloc(sizeof(iorange_t));
  72
  73         newrange->name = name;
  74         newrange->ops = ops;
  75         newrange->start = rstart;
  76         newrange->end = rend;
  77         newrange->next = ioranges;
  78
  79         ioranges = newrange;
  80
  81         return 0;
  82 }
  83
  84 int is_loaded(const char *plugin_name)
  85 {
  86         plugin_t *p = plugins;
  87         while (p) {
  88                 if (!strcmp(plugin_name, p->name))
  89                         return -1;
  90                 p = p->next;
  91         }
  92         return 0;
  93 }
  94
  95 int load_plugin(const char *plugin_name)
  96 {
  97         void *handle;
  98         char *error;
  99         char path[PATHSIZE];
 100
 101         int (*init_plugin) (void);
 102         char **deps;
 103         char **plugin_info;
 104         plugin_t *p;
 105
 106         if (is_loaded(plugin_name)) {
 107                 printf("Plugin %s already loaded.\n", plugin_name);
 108                 return 0;
 109         }
 110
 111         strncpy(path, PLUGINDIR, PATHSIZE);
 112         strncat(path, "/plugin_", PATHSIZE);
 113         strncat(path, plugin_name, PATHSIZE);
 114         strncat(path, ".so", PATHSIZE);
 115
 116 #if DEBUG
 117         printf("Opening plugin %s\n", path);
 118 #endif
 119
 120         handle = dlopen(path, RTLD_LAZY | RTLD_GLOBAL);
 121         if (!handle) {
 122                 error = dlerror();
 123                 printf("Error: Could not open plugin \"%s\": %s\n",
 124                        plugin_name, error);
 125                 exit(1);
 126         }
 127 #ifdef DEBUG_PLUGINS
 128         plugin_info = dlsym(handle, "plugin_author");
 129         if ((error = dlerror()) == NULL)
 130                 printf("Plugin %s author:  %s\n", plugin_name, *plugin_info);
 131         plugin_info = dlsym(handle, "plugin_license");
 132         if ((error = dlerror()) == NULL)
 133                 printf("Plugin %s license: %s\n", plugin_name, *plugin_info);
 134         plugin_info = dlsym(handle, "plugin_description");
 135         if ((error = dlerror()) == NULL)
 136                 printf("Plugin %s descr.: %s\n", plugin_name, *plugin_info);
 137 #endif
 138         p = malloc(sizeof(plugin_t));
 139         p->next = plugins;
 140         p->name = plugin_name;
 141         plugins = p;
 142
 143         deps = dlsym(handle, "plugin_deps");
 144         if ((error = dlerror()) != NULL)
 145                 deps = NULL;
 146
 147
 148         strncpy(path, "plugin_", PATHSIZE);
 149         strncat(path, plugin_name, PATHSIZE);
 150         strncat(path, "_init", PATHSIZE);
 151
 152         init_plugin = dlsym(handle, path);
 153         if ((error = dlerror()) != NULL) {
 154                 printf("error: %s\n", error);
 155                 exit(1);
 156         }
 157
 158         if (deps) {
 159                 int i = 0;
 160                 char *walk = deps[0];
 161 #ifdef DEBUG_PLUGINS
 162                 printf("\nPlugin %s dependencies:", plugin_name);
 163 #endif
 164                 while (walk) {
 165                         printf(" %s", walk);
 166                         if (!is_loaded(walk)) {
 167 #ifdef DEBUG_PLUGINS
 168                                 printf("(loading)\n");
 169 #endif
 170                                 load_plugin(walk);
 171                         }
 172 #ifdef DEBUG_PLUGINS
 173                         else {
 174                                 printf("(loaded)");
 175                         }
 176 #endif
 177                         walk = deps[++i];
 178                 }
 179         }
 180
 181         printf("\n");
 182 #if DEBUG
 183         printf("Initializing module:\n");
 184 #endif
 185
 186         return init_plugin();
 187
 188         // We don't dlclose the handle here since
 189         // we want to keep our symbols for later use.
 190 }
 191
 192 int main(void)
 193 {
 194         iorange_t *r;
 195
 196         // load_plugin("kbd");
 197         // load_plugin("pci");
 198         load_plugin("qt");
 199
 200         printf("\nRegistered IO Ranges:\n");
 201         r = ioranges;
 202         while (r) {
 203                 printf("  %s: %x-%x\n", r->name, r->start, r->end);
 204                 r = r->next;
 205         }
 206
 207         sleep(10);
 208         return 0;
 209 }