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 "device_tree.h"
  24 #include "hw/loader.h"
  25 #include "qemu-option.h"
  26 #include "qemu-config.h"
  27
  28 #include <libfdt.h>
  29
  30 #define FDT_MAX_SIZE  0x10000
  31
  32 void *create_device_tree(int *sizep)
  33 {
  34     void *fdt;
  35     int ret;
  36
  37     *sizep = FDT_MAX_SIZE;
  38     fdt = g_malloc0(FDT_MAX_SIZE);
  39     ret = fdt_create(fdt, FDT_MAX_SIZE);
  40     if (ret < 0) {
  41         goto fail;
  42     }
  43     ret = fdt_begin_node(fdt, "");
  44     if (ret < 0) {
  45         goto fail;
  46     }
  47     ret = fdt_end_node(fdt);
  48     if (ret < 0) {
  49         goto fail;
  50     }
  51     ret = fdt_finish(fdt);
  52     if (ret < 0) {
  53         goto fail;
  54     }
  55     ret = fdt_open_into(fdt, fdt, *sizep);
  56     if (ret) {
  57         fprintf(stderr, "Unable to copy device tree in memory\n");
  58         exit(1);
  59     }
  60
  61     return fdt;
  62 fail:
  63     fprintf(stderr, "%s Couldn't create dt: %s\n", __func__, fdt_strerror(ret));
  64     exit(1);
  65 }
  66
  67 void *load_device_tree(const char *filename_path, int *sizep)
  68 {
  69     int dt_size;
  70     int dt_file_load_size;
  71     int ret;
  72     void *fdt = NULL;
  73
  74     *sizep = 0;
  75     dt_size = get_image_size(filename_path);
  76     if (dt_size < 0) {
  77         printf("Unable to get size of device tree file '%s'\n",
  78             filename_path);
  79         goto fail;
  80     }
  81
  82     /* Expand to 2x size to give enough room for manipulation.  */
  83     dt_size += 10000;
  84     dt_size *= 2;
  85     /* First allocate space in qemu for device tree */
  86     fdt = g_malloc0(dt_size);
  87
  88     dt_file_load_size = load_image(filename_path, fdt);
  89     if (dt_file_load_size < 0) {
  90         printf("Unable to open device tree file '%s'\n",
  91                filename_path);
  92         goto fail;
  93     }
  94
  95     ret = fdt_open_into(fdt, fdt, dt_size);
  96     if (ret) {
  97         printf("Unable to copy device tree in memory\n");
  98         goto fail;
  99     }
 100
 101     /* Check sanity of device tree */
 102     if (fdt_check_header(fdt)) {
 103         printf ("Device tree file loaded into memory is invalid: %s\n",
 104             filename_path);
 105         goto fail;
 106     }
 107     *sizep = dt_size;
 108     return fdt;
 109
 110 fail:
 111     g_free(fdt);
 112     return NULL;
 113 }
 114
 115 static int findnode_nofail(void *fdt, const char *node_path)
 116 {
 117     int offset;
 118
 119     offset = fdt_path_offset(fdt, node_path);
 120     if (offset < 0) {
 121         fprintf(stderr, "%s Couldn't find node %s: %s\n", __func__, node_path,
 122                 fdt_strerror(offset));
 123         exit(1);
 124     }
 125
 126     return offset;
 127 }
 128
 129 int qemu_devtree_setprop(void *fdt, const char *node_path,
 130                          const char *property, const void *val_array, int size)
 131 {
 132     int r;
 133
 134     r = fdt_setprop(fdt, findnode_nofail(fdt, node_path), property, val_array, size);
 135     if (r < 0) {
 136         fprintf(stderr, "%s: Couldn't set %s/%s: %s\n", __func__, node_path,
 137                 property, fdt_strerror(r));
 138         exit(1);
 139     }
 140
 141     return r;
 142 }
 143
 144 int qemu_devtree_setprop_cell(void *fdt, const char *node_path,
 145                               const char *property, uint32_t val)
 146 {
 147     int r;
 148
 149     r = fdt_setprop_cell(fdt, findnode_nofail(fdt, node_path), property, val);
 150     if (r < 0) {
 151         fprintf(stderr, "%s: Couldn't set %s/%s = %#08x: %s\n", __func__,
 152                 node_path, property, val, fdt_strerror(r));
 153         exit(1);
 154     }
 155
 156     return r;
 157 }
 158
 159 int qemu_devtree_setprop_u64(void *fdt, const char *node_path,
 160                              const char *property, uint64_t val)
 161 {
 162     val = cpu_to_be64(val);
 163     return qemu_devtree_setprop(fdt, node_path, property, &val, sizeof(val));
 164 }
 165
 166 int qemu_devtree_setprop_string(void *fdt, const char *node_path,
 167                                 const char *property, const char *string)
 168 {
 169     int r;
 170
 171     r = fdt_setprop_string(fdt, findnode_nofail(fdt, node_path), property, string);
 172     if (r < 0) {
 173         fprintf(stderr, "%s: Couldn't set %s/%s = %s: %s\n", __func__,
 174                 node_path, property, string, fdt_strerror(r));
 175         exit(1);
 176     }
 177
 178     return r;
 179 }
 180
 181 const void *qemu_devtree_getprop(void *fdt, const char *node_path,
 182                                  const char *property, int *lenp)
 183 {
 184     int len;
 185     const void *r;
 186     if (!lenp) {
 187         lenp = &len;
 188     }
 189     r = fdt_getprop(fdt, findnode_nofail(fdt, node_path), property, lenp);
 190     if (!r) {
 191         fprintf(stderr, "%s: Couldn't get %s/%s: %s\n", __func__,
 192                 node_path, property, fdt_strerror(*lenp));
 193         exit(1);
 194     }
 195     return r;
 196 }
 197
 198 uint32_t qemu_devtree_getprop_cell(void *fdt, const char *node_path,
 199                                    const char *property)
 200 {
 201     int len;
 202     const uint32_t *p = qemu_devtree_getprop(fdt, node_path, property, &len);
 203     if (len != 4) {
 204         fprintf(stderr, "%s: %s/%s not 4 bytes long (not a cell?)\n",
 205                 __func__, node_path, property);
 206         exit(1);
 207     }
 208     return be32_to_cpu(*p);
 209 }
 210
 211 uint32_t qemu_devtree_get_phandle(void *fdt, const char *path)
 212 {
 213     uint32_t r;
 214
 215     r = fdt_get_phandle(fdt, findnode_nofail(fdt, path));
 216     if (r <= 0) {
 217         fprintf(stderr, "%s: Couldn't get phandle for %s: %s\n", __func__,
 218                 path, fdt_strerror(r));
 219         exit(1);
 220     }
 221
 222     return r;
 223 }
 224
 225 int qemu_devtree_setprop_phandle(void *fdt, const char *node_path,
 226                                  const char *property,
 227                                  const char *target_node_path)
 228 {
 229     uint32_t phandle = qemu_devtree_get_phandle(fdt, target_node_path);
 230     return qemu_devtree_setprop_cell(fdt, node_path, property, phandle);
 231 }
 232
 233 uint32_t qemu_devtree_alloc_phandle(void *fdt)
 234 {
 235     static int phandle = 0x0;
 236
 237     /*
 238      * We need to find out if the user gave us special instruction at
 239      * which phandle id to start allocting phandles.
 240      */
 241     if (!phandle) {
 242         QemuOpts *machine_opts;
 243         machine_opts = qemu_opts_find(qemu_find_opts("machine"), 0);
 244         if (machine_opts) {
 245             const char *phandle_start;
 246             phandle_start = qemu_opt_get(machine_opts, "phandle_start");
 247             if (phandle_start) {
 248                 phandle = strtoul(phandle_start, NULL, 0);
 249             }
 250         }
 251     }
 252
 253     if (!phandle) {
 254         /*
 255          * None or invalid phandle given on the command line, so fall back to
 256          * default starting point.
 257          */
 258         phandle = 0x8000;
 259     }
 260
 261     return phandle++;
 262 }
 263
 264 int qemu_devtree_nop_node(void *fdt, const char *node_path)
 265 {
 266     int r;
 267
 268     r = fdt_nop_node(fdt, findnode_nofail(fdt, node_path));
 269     if (r < 0) {
 270         fprintf(stderr, "%s: Couldn't nop node %s: %s\n", __func__, node_path,
 271                 fdt_strerror(r));
 272         exit(1);
 273     }
 274
 275     return r;
 276 }
 277
 278 int qemu_devtree_add_subnode(void *fdt, const char *name)
 279 {
 280     char *dupname = g_strdup(name);
 281     char *basename = strrchr(dupname, '/');
 282     int retval;
 283     int parent = 0;
 284
 285     if (!basename) {
 286         g_free(dupname);
 287         return -1;
 288     }
 289
 290     basename[0] = '\0';
 291     basename++;
 292
 293     if (dupname[0]) {
 294         parent = findnode_nofail(fdt, dupname);
 295     }
 296
 297     retval = fdt_add_subnode(fdt, parent, basename);
 298     if (retval < 0) {
 299         fprintf(stderr, "FDT: Failed to create subnode %s: %s\n", name,
 300                 fdt_strerror(retval));
 301         exit(1);
 302     }
 303
 304     g_free(dupname);
 305     return retval;
 306 }