device_tree.c

   1 /*
   2  * Functions to help device tree manipulation using libfdt.
   3  * It also provides functions to read entries from device tree proc
   4  * interface.
   5  *
   6  * Copyright 2008 IBM Corporation.
   7  * Authors: Jerone Young <jyoung5@us.ibm.com>
   8  *          Hollis Blanchard <hollisb@us.ibm.com>
   9  *
  10  * This work is licensed under the GNU GPL license version 2 or later.
  11  *
  12  */
  13
  14 #include <stdio.h>
  15 #include <sys/types.h>
  16 #include <sys/stat.h>
  17 #include <fcntl.h>
  18 #include <unistd.h>
  19 #include <stdlib.h>
  20
  21 #include "config.h"
  22 #include "qemu-common.h"
  23 #include "sysemu/device_tree.h"
  24 #include "sysemu/sysemu.h"
  25 #include "hw/loader.h"
  26 #include "qemu/option.h"
  27 #include "qemu/config-file.h"
  28
  29 #include <libfdt.h>
  30
  31 #define FDT_MAX_SIZE  0x10000
  32
  33 void *create_device_tree(int *sizep)
  34 {
  35     void *fdt;
  36     int ret;
  37
  38     *sizep = FDT_MAX_SIZE;
  39     fdt = g_malloc0(FDT_MAX_SIZE);
  40     ret = fdt_create(fdt, FDT_MAX_SIZE);
  41     if (ret < 0) {
  42         goto fail;
  43     }
  44     ret = fdt_finish_reservemap(fdt);
  45     if (ret < 0) {
  46         goto fail;
  47     }
  48     ret = fdt_begin_node(fdt, "");
  49     if (ret < 0) {
  50         goto fail;
  51     }
  52     ret = fdt_end_node(fdt);
  53     if (ret < 0) {
  54         goto fail;
  55     }
  56     ret = fdt_finish(fdt);
  57     if (ret < 0) {
  58         goto fail;
  59     }
  60     ret = fdt_open_into(fdt, fdt, *sizep);
  61     if (ret) {
  62         fprintf(stderr, "Unable to copy device tree in memory\n");
  63         exit(1);
  64     }
  65
  66     return fdt;
  67 fail:
  68     fprintf(stderr, "%s Couldn't create dt: %s\n", __func__, fdt_strerror(ret));
  69     exit(1);
  70 }
  71
  72 void *load_device_tree(const char *filename_path, int *sizep)
  73 {
  74     int dt_size;
  75     int dt_file_load_size;
  76     int ret;
  77     void *fdt = NULL;
  78
  79     *sizep = 0;
  80     dt_size = get_image_size(filename_path);
  81     if (dt_size < 0) {
  82         printf("Unable to get size of device tree file '%s'\n",
  83             filename_path);
  84         goto fail;
  85     }
  86
  87     /* Expand to 2x size to give enough room for manipulation.  */
  88     dt_size += 10000;
  89     dt_size *= 2;
  90     /* First allocate space in qemu for device tree */
  91     fdt = g_malloc0(dt_size);
  92
  93     dt_file_load_size = load_image(filename_path, fdt);
  94     if (dt_file_load_size < 0) {
  95         printf("Unable to open device tree file '%s'\n",
  96                filename_path);
  97         goto fail;
  98     }
  99
 100     ret = fdt_open_into(fdt, fdt, dt_size);
 101     if (ret) {
 102         printf("Unable to copy device tree in memory\n");
 103         goto fail;
 104     }
 105
 106     /* Check sanity of device tree */
 107     if (fdt_check_header(fdt)) {
 108         printf ("Device tree file loaded into memory is invalid: %s\n",
 109             filename_path);
 110         goto fail;
 111     }
 112     *sizep = dt_size;
 113     return fdt;
 114
 115 fail:
 116     g_free(fdt);
 117     return NULL;
 118 }
 119
 120 static int findnode_nofail(void *fdt, const char *node_path)
 121 {
 122     int offset;
 123
 124     offset = fdt_path_offset(fdt, node_path);
 125     if (offset < 0) {
 126         fprintf(stderr, "%s Couldn't find node %s: %s\n", __func__, node_path,
 127                 fdt_strerror(offset));
 128         exit(1);
 129     }
 130
 131     return offset;
 132 }
 133
 134 int qemu_fdt_setprop(void *fdt, const char *node_path,
 135                      const char *property, const void *val, int size)
 136 {
 137     int r;
 138
 139     r = fdt_setprop(fdt, findnode_nofail(fdt, node_path), property, val, size);
 140     if (r < 0) {
 141         fprintf(stderr, "%s: Couldn't set %s/%s: %s\n", __func__, node_path,
 142                 property, fdt_strerror(r));
 143         exit(1);
 144     }
 145
 146     return r;
 147 }
 148
 149 int qemu_fdt_setprop_cell(void *fdt, const char *node_path,
 150                           const char *property, uint32_t val)
 151 {
 152     int r;
 153
 154     r = fdt_setprop_cell(fdt, findnode_nofail(fdt, node_path), property, val);
 155     if (r < 0) {
 156         fprintf(stderr, "%s: Couldn't set %s/%s = %#08x: %s\n", __func__,
 157                 node_path, property, val, fdt_strerror(r));
 158         exit(1);
 159     }
 160
 161     return r;
 162 }
 163
 164 int qemu_fdt_setprop_u64(void *fdt, const char *node_path,
 165                          const char *property, uint64_t val)
 166 {
 167     val = cpu_to_be64(val);
 168     return qemu_fdt_setprop(fdt, node_path, property, &val, sizeof(val));
 169 }
 170
 171 int qemu_fdt_setprop_string(void *fdt, const char *node_path,
 172                             const char *property, const char *string)
 173 {
 174     int r;
 175
 176     r = fdt_setprop_string(fdt, findnode_nofail(fdt, node_path), property, string);
 177     if (r < 0) {
 178         fprintf(stderr, "%s: Couldn't set %s/%s = %s: %s\n", __func__,
 179                 node_path, property, string, fdt_strerror(r));
 180         exit(1);
 181     }
 182
 183     return r;
 184 }
 185
 186 const void *qemu_fdt_getprop(void *fdt, const char *node_path,
 187                              const char *property, int *lenp)
 188 {
 189     int len;
 190     const void *r;
 191     if (!lenp) {
 192         lenp = &len;
 193     }
 194     r = fdt_getprop(fdt, findnode_nofail(fdt, node_path), property, lenp);
 195     if (!r) {
 196         fprintf(stderr, "%s: Couldn't get %s/%s: %s\n", __func__,
 197                 node_path, property, fdt_strerror(*lenp));
 198         exit(1);
 199     }
 200     return r;
 201 }
 202
 203 uint32_t qemu_fdt_getprop_cell(void *fdt, const char *node_path,
 204                                const char *property)
 205 {
 206     int len;
 207     const uint32_t *p = qemu_fdt_getprop(fdt, node_path, property, &len);
 208     if (len != 4) {
 209         fprintf(stderr, "%s: %s/%s not 4 bytes long (not a cell?)\n",
 210                 __func__, node_path, property);
 211         exit(1);
 212     }
 213     return be32_to_cpu(*p);
 214 }
 215
 216 uint32_t qemu_fdt_get_phandle(void *fdt, const char *path)
 217 {
 218     uint32_t r;
 219
 220     r = fdt_get_phandle(fdt, findnode_nofail(fdt, path));
 221     if (r == 0) {
 222         fprintf(stderr, "%s: Couldn't get phandle for %s: %s\n", __func__,
 223                 path, fdt_strerror(r));
 224         exit(1);
 225     }
 226
 227     return r;
 228 }
 229
 230 int qemu_fdt_setprop_phandle(void *fdt, const char *node_path,
 231                              const char *property,
 232                              const char *target_node_path)
 233 {
 234     uint32_t phandle = qemu_fdt_get_phandle(fdt, target_node_path);
 235     return qemu_fdt_setprop_cell(fdt, node_path, property, phandle);
 236 }
 237
 238 uint32_t qemu_fdt_alloc_phandle(void *fdt)
 239 {
 240     static int phandle = 0x0;
 241
 242     /*
 243      * We need to find out if the user gave us special instruction at
 244      * which phandle id to start allocting phandles.
 245      */
 246     if (!phandle) {
 247         phandle = qemu_opt_get_number(qemu_get_machine_opts(),
 248                                       "phandle_start", 0);
 249     }
 250
 251     if (!phandle) {
 252         /*
 253          * None or invalid phandle given on the command line, so fall back to
 254          * default starting point.
 255          */
 256         phandle = 0x8000;
 257     }
 258
 259     return phandle++;
 260 }
 261
 262 int qemu_fdt_nop_node(void *fdt, const char *node_path)
 263 {
 264     int r;
 265
 266     r = fdt_nop_node(fdt, findnode_nofail(fdt, node_path));
 267     if (r < 0) {
 268         fprintf(stderr, "%s: Couldn't nop node %s: %s\n", __func__, node_path,
 269                 fdt_strerror(r));
 270         exit(1);
 271     }
 272
 273     return r;
 274 }
 275
 276 int qemu_fdt_add_subnode(void *fdt, const char *name)
 277 {
 278     char *dupname = g_strdup(name);
 279     char *basename = strrchr(dupname, '/');
 280     int retval;
 281     int parent = 0;
 282
 283     if (!basename) {
 284         g_free(dupname);
 285         return -1;
 286     }
 287
 288     basename[0] = '\0';
 289     basename++;
 290
 291     if (dupname[0]) {
 292         parent = findnode_nofail(fdt, dupname);
 293     }
 294
 295     retval = fdt_add_subnode(fdt, parent, basename);
 296     if (retval < 0) {
 297         fprintf(stderr, "FDT: Failed to create subnode %s: %s\n", name,
 298                 fdt_strerror(retval));
 299         exit(1);
 300     }
 301
 302     g_free(dupname);
 303     return retval;
 304 }
 305
 306 void qemu_fdt_dumpdtb(void *fdt, int size)
 307 {
 308     const char *dumpdtb = qemu_opt_get(qemu_get_machine_opts(), "dumpdtb");
 309
 310     if (dumpdtb) {
 311         /* Dump the dtb to a file and quit */
 312         exit(g_file_set_contents(dumpdtb, fdt, size, NULL) ? 0 : 1);
 313     }
 314 }
 315
 316 int qemu_fdt_setprop_sized_cells_from_array(void *fdt,
 317                                             const char *node_path,
 318                                             const char *property,
 319                                             int numvalues,
 320                                             uint64_t *values)
 321 {
 322     uint32_t *propcells;
 323     uint64_t value;
 324     int cellnum, vnum, ncells;
 325     uint32_t hival;
 326
 327     propcells = g_new0(uint32_t, numvalues * 2);
 328
 329     cellnum = 0;
 330     for (vnum = 0; vnum < numvalues; vnum++) {
 331         ncells = values[vnum * 2];
 332         if (ncells != 1 && ncells != 2) {
 333             return -1;
 334         }
 335         value = values[vnum * 2 + 1];
 336         hival = cpu_to_be32(value >> 32);
 337         if (ncells > 1) {
 338             propcells[cellnum++] = hival;
 339         } else if (hival != 0) {
 340             return -1;
 341         }
 342         propcells[cellnum++] = cpu_to_be32(value);
 343     }
 344
 345     return qemu_fdt_setprop(fdt, node_path, property, propcells,
 346                             cellnum * sizeof(uint32_t));
 347 }