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 "qemu/error-report.h"
  24 #include "sysemu/device_tree.h"
  25 #include "sysemu/sysemu.h"
  26 #include "hw/loader.h"
  27 #include "qemu/option.h"
  28 #include "qemu/config-file.h"
  29
  30 #include <libfdt.h>
  31
  32 #define FDT_MAX_SIZE  0x10000
  33
  34 void *create_device_tree(int *sizep)
  35 {
  36     void *fdt;
  37     int ret;
  38
  39     *sizep = FDT_MAX_SIZE;
  40     fdt = g_malloc0(FDT_MAX_SIZE);
  41     ret = fdt_create(fdt, FDT_MAX_SIZE);
  42     if (ret < 0) {
  43         goto fail;
  44     }
  45     ret = fdt_finish_reservemap(fdt);
  46     if (ret < 0) {
  47         goto fail;
  48     }
  49     ret = fdt_begin_node(fdt, "");
  50     if (ret < 0) {
  51         goto fail;
  52     }
  53     ret = fdt_end_node(fdt);
  54     if (ret < 0) {
  55         goto fail;
  56     }
  57     ret = fdt_finish(fdt);
  58     if (ret < 0) {
  59         goto fail;
  60     }
  61     ret = fdt_open_into(fdt, fdt, *sizep);
  62     if (ret) {
  63         error_report("Unable to copy device tree in memory");
  64         exit(1);
  65     }
  66
  67     return fdt;
  68 fail:
  69     error_report("%s Couldn't create dt: %s", __func__, fdt_strerror(ret));
  70     exit(1);
  71 }
  72
  73 void *load_device_tree(const char *filename_path, int *sizep)
  74 {
  75     int dt_size;
  76     int dt_file_load_size;
  77     int ret;
  78     void *fdt = NULL;
  79
  80     *sizep = 0;
  81     dt_size = get_image_size(filename_path);
  82     if (dt_size < 0) {
  83         error_report("Unable to get size of device tree file '%s'",
  84                      filename_path);
  85         goto fail;
  86     }
  87
  88     /* Expand to 2x size to give enough room for manipulation.  */
  89     dt_size += 10000;
  90     dt_size *= 2;
  91     /* First allocate space in qemu for device tree */
  92     fdt = g_malloc0(dt_size);
  93
  94     dt_file_load_size = load_image(filename_path, fdt);
  95     if (dt_file_load_size < 0) {
  96         error_report("Unable to open device tree file '%s'",
  97                      filename_path);
  98         goto fail;
  99     }
 100
 101     ret = fdt_open_into(fdt, fdt, dt_size);
 102     if (ret) {
 103         error_report("Unable to copy device tree in memory");
 104         goto fail;
 105     }
 106
 107     /* Check sanity of device tree */
 108     if (fdt_check_header(fdt)) {
 109         error_report("Device tree file loaded into memory is invalid: %s",
 110                      filename_path);
 111         goto fail;
 112     }
 113     *sizep = dt_size;
 114     return fdt;
 115
 116 fail:
 117     g_free(fdt);
 118     return NULL;
 119 }
 120
 121 static int findnode_nofail(void *fdt, const char *node_path)
 122 {
 123     int offset;
 124
 125     offset = fdt_path_offset(fdt, node_path);
 126     if (offset < 0) {
 127         error_report("%s Couldn't find node %s: %s", __func__, node_path,
 128                      fdt_strerror(offset));
 129         exit(1);
 130     }
 131
 132     return offset;
 133 }
 134
 135 int qemu_fdt_setprop(void *fdt, const char *node_path,
 136                      const char *property, const void *val, int size)
 137 {
 138     int r;
 139
 140     r = fdt_setprop(fdt, findnode_nofail(fdt, node_path), property, val, size);
 141     if (r < 0) {
 142         error_report("%s: Couldn't set %s/%s: %s", __func__, node_path,
 143                      property, fdt_strerror(r));
 144         exit(1);
 145     }
 146
 147     return r;
 148 }
 149
 150 int qemu_fdt_setprop_cell(void *fdt, const char *node_path,
 151                           const char *property, uint32_t val)
 152 {
 153     int r;
 154
 155     r = fdt_setprop_cell(fdt, findnode_nofail(fdt, node_path), property, val);
 156     if (r < 0) {
 157         error_report("%s: Couldn't set %s/%s = %#08x: %s", __func__,
 158                      node_path, property, val, fdt_strerror(r));
 159         exit(1);
 160     }
 161
 162     return r;
 163 }
 164
 165 int qemu_fdt_setprop_u64(void *fdt, const char *node_path,
 166                          const char *property, uint64_t val)
 167 {
 168     val = cpu_to_be64(val);
 169     return qemu_fdt_setprop(fdt, node_path, property, &val, sizeof(val));
 170 }
 171
 172 int qemu_fdt_setprop_string(void *fdt, const char *node_path,
 173                             const char *property, const char *string)
 174 {
 175     int r;
 176
 177     r = fdt_setprop_string(fdt, findnode_nofail(fdt, node_path), property, string);
 178     if (r < 0) {
 179         error_report("%s: Couldn't set %s/%s = %s: %s", __func__,
 180                      node_path, property, string, fdt_strerror(r));
 181         exit(1);
 182     }
 183
 184     return r;
 185 }
 186
 187 const void *qemu_fdt_getprop(void *fdt, const char *node_path,
 188                              const char *property, int *lenp)
 189 {
 190     int len;
 191     const void *r;
 192     if (!lenp) {
 193         lenp = &len;
 194     }
 195     r = fdt_getprop(fdt, findnode_nofail(fdt, node_path), property, lenp);
 196     if (!r) {
 197         error_report("%s: Couldn't get %s/%s: %s", __func__,
 198                      node_path, property, fdt_strerror(*lenp));
 199         exit(1);
 200     }
 201     return r;
 202 }
 203
 204 uint32_t qemu_fdt_getprop_cell(void *fdt, const char *node_path,
 205                                const char *property)
 206 {
 207     int len;
 208     const uint32_t *p = qemu_fdt_getprop(fdt, node_path, property, &len);
 209     if (len != 4) {
 210         error_report("%s: %s/%s not 4 bytes long (not a cell?)",
 211                      __func__, node_path, property);
 212         exit(1);
 213     }
 214     return be32_to_cpu(*p);
 215 }
 216
 217 uint32_t qemu_fdt_get_phandle(void *fdt, const char *path)
 218 {
 219     uint32_t r;
 220
 221     r = fdt_get_phandle(fdt, findnode_nofail(fdt, path));
 222     if (r == 0) {
 223         error_report("%s: Couldn't get phandle for %s: %s", __func__,
 224                      path, fdt_strerror(r));
 225         exit(1);
 226     }
 227
 228     return r;
 229 }
 230
 231 int qemu_fdt_setprop_phandle(void *fdt, const char *node_path,
 232                              const char *property,
 233                              const char *target_node_path)
 234 {
 235     uint32_t phandle = qemu_fdt_get_phandle(fdt, target_node_path);
 236     return qemu_fdt_setprop_cell(fdt, node_path, property, phandle);
 237 }
 238
 239 uint32_t qemu_fdt_alloc_phandle(void *fdt)
 240 {
 241     static int phandle = 0x0;
 242
 243     /*
 244      * We need to find out if the user gave us special instruction at
 245      * which phandle id to start allocting phandles.
 246      */
 247     if (!phandle) {
 248         phandle = qemu_opt_get_number(qemu_get_machine_opts(),
 249                                       "phandle_start", 0);
 250     }
 251
 252     if (!phandle) {
 253         /*
 254          * None or invalid phandle given on the command line, so fall back to
 255          * default starting point.
 256          */
 257         phandle = 0x8000;
 258     }
 259
 260     return phandle++;
 261 }
 262
 263 int qemu_fdt_nop_node(void *fdt, const char *node_path)
 264 {
 265     int r;
 266
 267     r = fdt_nop_node(fdt, findnode_nofail(fdt, node_path));
 268     if (r < 0) {
 269         error_report("%s: Couldn't nop node %s: %s", __func__, node_path,
 270                      fdt_strerror(r));
 271         exit(1);
 272     }
 273
 274     return r;
 275 }
 276
 277 int qemu_fdt_add_subnode(void *fdt, const char *name)
 278 {
 279     char *dupname = g_strdup(name);
 280     char *basename = strrchr(dupname, '/');
 281     int retval;
 282     int parent = 0;
 283
 284     if (!basename) {
 285         g_free(dupname);
 286         return -1;
 287     }
 288
 289     basename[0] = '\0';
 290     basename++;
 291
 292     if (dupname[0]) {
 293         parent = findnode_nofail(fdt, dupname);
 294     }
 295
 296     retval = fdt_add_subnode(fdt, parent, basename);
 297     if (retval < 0) {
 298         error_report("FDT: Failed to create subnode %s: %s", name,
 299                      fdt_strerror(retval));
 300         exit(1);
 301     }
 302
 303     g_free(dupname);
 304     return retval;
 305 }
 306
 307 void qemu_fdt_dumpdtb(void *fdt, int size)
 308 {
 309     const char *dumpdtb = qemu_opt_get(qemu_get_machine_opts(), "dumpdtb");
 310
 311     if (dumpdtb) {
 312         /* Dump the dtb to a file and quit */
 313         exit(g_file_set_contents(dumpdtb, fdt, size, NULL) ? 0 : 1);
 314     }
 315 }
 316
 317 int qemu_fdt_setprop_sized_cells_from_array(void *fdt,
 318                                             const char *node_path,
 319                                             const char *property,
 320                                             int numvalues,
 321                                             uint64_t *values)
 322 {
 323     uint32_t *propcells;
 324     uint64_t value;
 325     int cellnum, vnum, ncells;
 326     uint32_t hival;
 327
 328     propcells = g_new0(uint32_t, numvalues * 2);
 329
 330     cellnum = 0;
 331     for (vnum = 0; vnum < numvalues; vnum++) {
 332         ncells = values[vnum * 2];
 333         if (ncells != 1 && ncells != 2) {
 334             return -1;
 335         }
 336         value = values[vnum * 2 + 1];
 337         hival = cpu_to_be32(value >> 32);
 338         if (ncells > 1) {
 339             propcells[cellnum++] = hival;
 340         } else if (hival != 0) {
 341             return -1;
 342         }
 343         propcells[cellnum++] = cpu_to_be32(value);
 344     }
 345
 346     return qemu_fdt_setprop(fdt, node_path, property, propcells,
 347                             cellnum * sizeof(uint32_t));
 348 }