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_begin_node(fdt, "");
  45     if (ret < 0) {
  46         goto fail;
  47     }
  48     ret = fdt_end_node(fdt);
  49     if (ret < 0) {
  50         goto fail;
  51     }
  52     ret = fdt_finish(fdt);
  53     if (ret < 0) {
  54         goto fail;
  55     }
  56     ret = fdt_open_into(fdt, fdt, *sizep);
  57     if (ret) {
  58         fprintf(stderr, "Unable to copy device tree in memory\n");
  59         exit(1);
  60     }
  61
  62     return fdt;
  63 fail:
  64     fprintf(stderr, "%s Couldn't create dt: %s\n", __func__, fdt_strerror(ret));
  65     exit(1);
  66 }
  67
  68 void *load_device_tree(const char *filename_path, int *sizep)
  69 {
  70     int dt_size;
  71     int dt_file_load_size;
  72     int ret;
  73     void *fdt = NULL;
  74
  75     *sizep = 0;
  76     dt_size = get_image_size(filename_path);
  77     if (dt_size < 0) {
  78         printf("Unable to get size of device tree file '%s'\n",
  79             filename_path);
  80         goto fail;
  81     }
  82
  83     /* Expand to 2x size to give enough room for manipulation.  */
  84     dt_size += 10000;
  85     dt_size *= 2;
  86     /* First allocate space in qemu for device tree */
  87     fdt = g_malloc0(dt_size);
  88
  89     dt_file_load_size = load_image(filename_path, fdt);
  90     if (dt_file_load_size < 0) {
  91         printf("Unable to open device tree file '%s'\n",
  92                filename_path);
  93         goto fail;
  94     }
  95
  96     ret = fdt_open_into(fdt, fdt, dt_size);
  97     if (ret) {
  98         printf("Unable to copy device tree in memory\n");
  99         goto fail;
 100     }
 101
 102     /* Check sanity of device tree */
 103     if (fdt_check_header(fdt)) {
 104         printf ("Device tree file loaded into memory is invalid: %s\n",
 105             filename_path);
 106         goto fail;
 107     }
 108     *sizep = dt_size;
 109     return fdt;
 110
 111 fail:
 112     g_free(fdt);
 113     return NULL;
 114 }
 115
 116 static int findnode_nofail(void *fdt, const char *node_path)
 117 {
 118     int offset;
 119
 120     offset = fdt_path_offset(fdt, node_path);
 121     if (offset < 0) {
 122         fprintf(stderr, "%s Couldn't find node %s: %s\n", __func__, node_path,
 123                 fdt_strerror(offset));
 124         exit(1);
 125     }
 126
 127     return offset;
 128 }
 129
 130 int qemu_devtree_setprop(void *fdt, const char *node_path,
 131                          const char *property, const void *val_array, int size)
 132 {
 133     int r;
 134
 135     r = fdt_setprop(fdt, findnode_nofail(fdt, node_path), property, val_array, size);
 136     if (r < 0) {
 137         fprintf(stderr, "%s: Couldn't set %s/%s: %s\n", __func__, node_path,
 138                 property, fdt_strerror(r));
 139         exit(1);
 140     }
 141
 142     return r;
 143 }
 144
 145 int qemu_devtree_setprop_cell(void *fdt, const char *node_path,
 146                               const char *property, uint32_t val)
 147 {
 148     int r;
 149
 150     r = fdt_setprop_cell(fdt, findnode_nofail(fdt, node_path), property, val);
 151     if (r < 0) {
 152         fprintf(stderr, "%s: Couldn't set %s/%s = %#08x: %s\n", __func__,
 153                 node_path, property, val, fdt_strerror(r));
 154         exit(1);
 155     }
 156
 157     return r;
 158 }
 159
 160 int qemu_devtree_setprop_u64(void *fdt, const char *node_path,
 161                              const char *property, uint64_t val)
 162 {
 163     val = cpu_to_be64(val);
 164     return qemu_devtree_setprop(fdt, node_path, property, &val, sizeof(val));
 165 }
 166
 167 int qemu_devtree_setprop_string(void *fdt, const char *node_path,
 168                                 const char *property, const char *string)
 169 {
 170     int r;
 171
 172     r = fdt_setprop_string(fdt, findnode_nofail(fdt, node_path), property, string);
 173     if (r < 0) {
 174         fprintf(stderr, "%s: Couldn't set %s/%s = %s: %s\n", __func__,
 175                 node_path, property, string, fdt_strerror(r));
 176         exit(1);
 177     }
 178
 179     return r;
 180 }
 181
 182 const void *qemu_devtree_getprop(void *fdt, const char *node_path,
 183                                  const char *property, int *lenp)
 184 {
 185     int len;
 186     const void *r;
 187     if (!lenp) {
 188         lenp = &len;
 189     }
 190     r = fdt_getprop(fdt, findnode_nofail(fdt, node_path), property, lenp);
 191     if (!r) {
 192         fprintf(stderr, "%s: Couldn't get %s/%s: %s\n", __func__,
 193                 node_path, property, fdt_strerror(*lenp));
 194         exit(1);
 195     }
 196     return r;
 197 }
 198
 199 uint32_t qemu_devtree_getprop_cell(void *fdt, const char *node_path,
 200                                    const char *property)
 201 {
 202     int len;
 203     const uint32_t *p = qemu_devtree_getprop(fdt, node_path, property, &len);
 204     if (len != 4) {
 205         fprintf(stderr, "%s: %s/%s not 4 bytes long (not a cell?)\n",
 206                 __func__, node_path, property);
 207         exit(1);
 208     }
 209     return be32_to_cpu(*p);
 210 }
 211
 212 uint32_t qemu_devtree_get_phandle(void *fdt, const char *path)
 213 {
 214     uint32_t r;
 215
 216     r = fdt_get_phandle(fdt, findnode_nofail(fdt, path));
 217     if (r == 0) {
 218         fprintf(stderr, "%s: Couldn't get phandle for %s: %s\n", __func__,
 219                 path, fdt_strerror(r));
 220         exit(1);
 221     }
 222
 223     return r;
 224 }
 225
 226 int qemu_devtree_setprop_phandle(void *fdt, const char *node_path,
 227                                  const char *property,
 228                                  const char *target_node_path)
 229 {
 230     uint32_t phandle = qemu_devtree_get_phandle(fdt, target_node_path);
 231     return qemu_devtree_setprop_cell(fdt, node_path, property, phandle);
 232 }
 233
 234 uint32_t qemu_devtree_alloc_phandle(void *fdt)
 235 {
 236     static int phandle = 0x0;
 237
 238     /*
 239      * We need to find out if the user gave us special instruction at
 240      * which phandle id to start allocting phandles.
 241      */
 242     if (!phandle) {
 243         phandle = qemu_opt_get_number(qemu_get_machine_opts(),
 244                                       "phandle_start", 0);
 245     }
 246
 247     if (!phandle) {
 248         /*
 249          * None or invalid phandle given on the command line, so fall back to
 250          * default starting point.
 251          */
 252         phandle = 0x8000;
 253     }
 254
 255     return phandle++;
 256 }
 257
 258 int qemu_devtree_nop_node(void *fdt, const char *node_path)
 259 {
 260     int r;
 261
 262     r = fdt_nop_node(fdt, findnode_nofail(fdt, node_path));
 263     if (r < 0) {
 264         fprintf(stderr, "%s: Couldn't nop node %s: %s\n", __func__, node_path,
 265                 fdt_strerror(r));
 266         exit(1);
 267     }
 268
 269     return r;
 270 }
 271
 272 int qemu_devtree_add_subnode(void *fdt, const char *name)
 273 {
 274     char *dupname = g_strdup(name);
 275     char *basename = strrchr(dupname, '/');
 276     int retval;
 277     int parent = 0;
 278
 279     if (!basename) {
 280         g_free(dupname);
 281         return -1;
 282     }
 283
 284     basename[0] = '\0';
 285     basename++;
 286
 287     if (dupname[0]) {
 288         parent = findnode_nofail(fdt, dupname);
 289     }
 290
 291     retval = fdt_add_subnode(fdt, parent, basename);
 292     if (retval < 0) {
 293         fprintf(stderr, "FDT: Failed to create subnode %s: %s\n", name,
 294                 fdt_strerror(retval));
 295         exit(1);
 296     }
 297
 298     g_free(dupname);
 299     return retval;
 300 }
 301
 302 void qemu_devtree_dumpdtb(void *fdt, int size)
 303 {
 304     const char *dumpdtb = qemu_opt_get(qemu_get_machine_opts(), "dumpdtb");
 305
 306     if (dumpdtb) {
 307         /* Dump the dtb to a file and quit */
 308         exit(g_file_set_contents(dumpdtb, fdt, size, NULL) ? 0 : 1);
 309     }
 310 }