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

   1 /* tag: plugin interface for openbios forth kernel
   2  *
   3  * Copyright (C) 2003, 2004 Stefan Reinauer
   4  *
   5  * See the file "COPYING" for further information about
   6  * the copyright and warranty status of this work.
   7  */
   8
   9 #include "sysinclude.h"
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include <dlfcn.h>
  14
  15 #include "unix/plugins.h"
  16
  17 unsigned char *plugindir = "/usr/share/OpenBIOS/plugins";
  18 #define PLUGINDIR  plugindir
  19 #define PATHSIZE   256
  20
  21 #define CONFIG_DEBUG_PLUGINS
  22
  23 typedef struct iorange iorange_t;
  24 struct iorange {
  25         const char *name;
  26         unsigned int start;
  27         unsigned int end;
  28         io_ops_t *ops;
  29         iorange_t *next;
  30 };
  31
  32 static iorange_t *ioranges = NULL;
  33
  34 typedef struct plugin plugin_t;
  35 struct plugin {
  36         const char *name;
  37         plugin_t *next;
  38 };
  39
  40 static plugin_t *plugins = NULL;
  41
  42 io_ops_t *find_iorange(u32 reg)
  43 {
  44         iorange_t *range = ioranges;
  45         while (range) {
  46                 if (range->start <= reg && range->end >= reg)
  47                         return range->ops;
  48                 range = range->next;
  49         }
  50         return NULL;
  51 }
  52
  53 int register_iorange(const char *name, io_ops_t * ops, unsigned int rstart,
  54                      unsigned int rend)
  55 {
  56         iorange_t *newrange;
  57
  58         /* intersection check */
  59         newrange = ioranges;
  60         while (newrange) {
  61                 int fail = 0;
  62                 /* new section swallows old section */
  63                 if (newrange->start >= rstart && newrange->end <= rend)
  64                         fail = -1;
  65                 /* new section start or end point are within range */
  66                 if (newrange->start <= rstart && newrange->end >= rstart)
  67                         fail = -1;
  68                 if (newrange->start <= rend && newrange->end >= rend)
  69                         fail = -1;
  70                 if (fail) {
  71                         printf("Error: overlapping IO regions: %s and %s\n",
  72                                 newrange->name, name);
  73                         return -1;
  74                 }
  75                 newrange = newrange->next;
  76         }
  77
  78         newrange = malloc(sizeof(iorange_t));
  79
  80         newrange->name = name;
  81         newrange->ops = ops;
  82         newrange->start = rstart;
  83         newrange->end = rend;
  84         newrange->next = ioranges;
  85
  86         ioranges = newrange;
  87
  88         return 0;
  89 }
  90
  91 int is_loaded(const char *plugin_name)
  92 {
  93         plugin_t *p = plugins;
  94         while (p) {
  95                 if (!strcmp(plugin_name, p->name))
  96                         return -1;
  97                 p = p->next;
  98         }
  99         return 0;
 100 }
 101
 102 int load_plugin(const char *plugin_name)
 103 {
 104         void *handle;
 105         char *error;
 106         char path[PATHSIZE];
 107
 108         int (*init_plugin) (void);
 109         char **deps;
 110         char **plugin_info;
 111         plugin_t *p;
 112
 113         if (is_loaded(plugin_name)) {
 114                 printf("Plugin %s already loaded.\n", plugin_name);
 115                 return 0;
 116         }
 117
 118         strncpy(path, PLUGINDIR, PATHSIZE);
 119         strncat(path, "/plugin_", PATHSIZE);
 120         strncat(path, plugin_name, PATHSIZE);
 121         strncat(path, ".so", PATHSIZE);
 122
 123 #if DEBUG
 124         printf("Opening plugin %s\n", path);
 125 #endif
 126
 127         handle = dlopen(path, RTLD_LAZY | RTLD_GLOBAL);
 128         if (!handle) {
 129                 error = dlerror();
 130                 printf("Error: Could not open plugin \"%s\": %s\n",
 131                        plugin_name, error);
 132                 exit(1);
 133         }
 134 #ifdef CONFIG_DEBUG_PLUGINS
 135         plugin_info = dlsym(handle, "plugin_author");
 136         if ((error = dlerror()) == NULL)
 137                 printf("Plugin %s author:  %s\n", plugin_name, *plugin_info);
 138         plugin_info = dlsym(handle, "plugin_license");
 139         if ((error = dlerror()) == NULL)
 140                 printf("Plugin %s license: %s\n", plugin_name, *plugin_info);
 141         plugin_info = dlsym(handle, "plugin_description");
 142         if ((error = dlerror()) == NULL)
 143                 printf("Plugin %s descr.: %s\n", plugin_name, *plugin_info);
 144 #endif
 145         p = malloc(sizeof(plugin_t));
 146         p->next = plugins;
 147         p->name = plugin_name;
 148         plugins = p;
 149
 150         deps = dlsym(handle, "plugin_deps");
 151         if ((error = dlerror()) != NULL)
 152                 deps = NULL;
 153
 154
 155         strncpy(path, "plugin_", PATHSIZE);
 156         strncat(path, plugin_name, PATHSIZE);
 157         strncat(path, "_init", PATHSIZE);
 158
 159         init_plugin = dlsym(handle, path);
 160         if ((error = dlerror()) != NULL) {
 161                 printf("error: %s\n", error);
 162                 exit(1);
 163         }
 164
 165         if (deps) {
 166                 int i = 0;
 167                 char *walk = deps[0];
 168 #ifdef CONFIG_DEBUG_PLUGINS
 169                 printf("\nPlugin %s dependencies:", plugin_name);
 170 #endif
 171                 while (walk) {
 172                         printf(" %s", walk);
 173                         if (!is_loaded(walk)) {
 174 #ifdef CONFIG_DEBUG_PLUGINS
 175                                 printf("(loading)\n");
 176 #endif
 177                                 load_plugin(walk);
 178                         }
 179 #ifdef CONFIG_DEBUG_PLUGINS
 180                         else {
 181                                 printf("(loaded)");
 182                         }
 183 #endif
 184                         walk = deps[++i];
 185                 }
 186         }
 187
 188         printf("\n");
 189 #if DEBUG
 190         printf("Initializing module:\n");
 191 #endif
 192
 193         return init_plugin();
 194
 195         // We don't dlclose the handle here since
 196         // we want to keep our symbols for later use.
 197 }