scripts/dtc/fdtput.c

   1 /*
   2  * Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of
   7  * the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  17  * MA 02111-1307 USA
  18  */
  19
  20 #include <assert.h>
  21 #include <ctype.h>
  22 #include <getopt.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 #include <libfdt.h>
  28
  29 #include "util.h"
  30
  31 /* These are the operations we support */
  32 enum oper_type {
  33         OPER_WRITE_PROP,                /* Write a property in a node */
  34         OPER_CREATE_NODE,               /* Create a new node */
  35 };
  36
  37 struct display_info {
  38         enum oper_type oper;    /* operation to perform */
  39         int type;               /* data type (s/i/u/x or 0 for default) */
  40         int size;               /* data size (1/2/4) */
  41         int verbose;            /* verbose output */
  42         int auto_path;          /* automatically create all path components */
  43 };
  44
  45
  46 /**
  47  * Report an error with a particular node.
  48  *
  49  * @param name          Node name to report error on
  50  * @param namelen       Length of node name, or -1 to use entire string
  51  * @param err           Error number to report (-FDT_ERR_...)
  52  */
  53 static void report_error(const char *name, int namelen, int err)
  54 {
  55         if (namelen == -1)
  56                 namelen = strlen(name);
  57         fprintf(stderr, "Error at '%1.*s': %s\n", namelen, name,
  58                 fdt_strerror(err));
  59 }
  60
  61 /**
  62  * Encode a series of arguments in a property value.
  63  *
  64  * @param disp          Display information / options
  65  * @param arg           List of arguments from command line
  66  * @param arg_count     Number of arguments (may be 0)
  67  * @param valuep        Returns buffer containing value
  68  * @param *value_len    Returns length of value encoded
  69  */
  70 static int encode_value(struct display_info *disp, char **arg, int arg_count,
  71                         char **valuep, int *value_len)
  72 {
  73         char *value = NULL;     /* holding area for value */
  74         int value_size = 0;     /* size of holding area */
  75         char *ptr;              /* pointer to current value position */
  76         int len;                /* length of this cell/string/byte */
  77         int ival;
  78         int upto;       /* the number of bytes we have written to buf */
  79         char fmt[3];
  80
  81         upto = 0;
  82
  83         if (disp->verbose)
  84                 fprintf(stderr, "Decoding value:\n");
  85
  86         fmt[0] = '%';
  87         fmt[1] = disp->type ? disp->type : 'd';
  88         fmt[2] = '\0';
  89         for (; arg_count > 0; arg++, arg_count--, upto += len) {
  90                 /* assume integer unless told otherwise */
  91                 if (disp->type == 's')
  92                         len = strlen(*arg) + 1;
  93                 else
  94                         len = disp->size == -1 ? 4 : disp->size;
  95
  96                 /* enlarge our value buffer by a suitable margin if needed */
  97                 if (upto + len > value_size) {
  98                         value_size = (upto + len) + 500;
  99                         value = realloc(value, value_size);
 100                         if (!value) {
 101                                 fprintf(stderr, "Out of mmory: cannot alloc "
 102                                         "%d bytes\n", value_size);
 103                                 return -1;
 104                         }
 105                 }
 106
 107                 ptr = value + upto;
 108                 if (disp->type == 's') {
 109                         memcpy(ptr, *arg, len);
 110                         if (disp->verbose)
 111                                 fprintf(stderr, "\tstring: '%s'\n", ptr);
 112                 } else {
 113                         int *iptr = (int *)ptr;
 114                         sscanf(*arg, fmt, &ival);
 115                         if (len == 4)
 116                                 *iptr = cpu_to_fdt32(ival);
 117                         else
 118                                 *ptr = (uint8_t)ival;
 119                         if (disp->verbose) {
 120                                 fprintf(stderr, "\t%s: %d\n",
 121                                         disp->size == 1 ? "byte" :
 122                                         disp->size == 2 ? "short" : "int",
 123                                         ival);
 124                         }
 125                 }
 126         }
 127         *value_len = upto;
 128         *valuep = value;
 129         if (disp->verbose)
 130                 fprintf(stderr, "Value size %d\n", upto);
 131         return 0;
 132 }
 133
 134 static int store_key_value(void *blob, const char *node_name,
 135                 const char *property, const char *buf, int len)
 136 {
 137         int node;
 138         int err;
 139
 140         node = fdt_path_offset(blob, node_name);
 141         if (node < 0) {
 142                 report_error(node_name, -1, node);
 143                 return -1;
 144         }
 145
 146         err = fdt_setprop(blob, node, property, buf, len);
 147         if (err) {
 148                 report_error(property, -1, err);
 149                 return -1;
 150         }
 151         return 0;
 152 }
 153
 154 /**
 155  * Create paths as needed for all components of a path
 156  *
 157  * Any components of the path that do not exist are created. Errors are
 158  * reported.
 159  *
 160  * @param blob          FDT blob to write into
 161  * @param in_path       Path to process
 162  * @return 0 if ok, -1 on error
 163  */
 164 static int create_paths(void *blob, const char *in_path)
 165 {
 166         const char *path = in_path;
 167         const char *sep;
 168         int node, offset = 0;
 169
 170         /* skip leading '/' */
 171         while (*path == '/')
 172                 path++;
 173
 174         for (sep = path; *sep; path = sep + 1, offset = node) {
 175                 /* equivalent to strchrnul(), but it requires _GNU_SOURCE */
 176                 sep = strchr(path, '/');
 177                 if (!sep)
 178                         sep = path + strlen(path);
 179
 180                 node = fdt_subnode_offset_namelen(blob, offset, path,
 181                                 sep - path);
 182                 if (node == -FDT_ERR_NOTFOUND) {
 183                         node = fdt_add_subnode_namelen(blob, offset, path,
 184                                                        sep - path);
 185                 }
 186                 if (node < 0) {
 187                         report_error(path, sep - path, node);
 188                         return -1;
 189                 }
 190         }
 191
 192         return 0;
 193 }
 194
 195 /**
 196  * Create a new node in the fdt.
 197  *
 198  * This will overwrite the node_name string. Any error is reported.
 199  *
 200  * TODO: Perhaps create fdt_path_offset_namelen() so we don't need to do this.
 201  *
 202  * @param blob          FDT blob to write into
 203  * @param node_name     Name of node to create
 204  * @return new node offset if found, or -1 on failure
 205  */
 206 static int create_node(void *blob, const char *node_name)
 207 {
 208         int node = 0;
 209         char *p;
 210
 211         p = strrchr(node_name, '/');
 212         if (!p) {
 213                 report_error(node_name, -1, -FDT_ERR_BADPATH);
 214                 return -1;
 215         }
 216         *p = '\0';
 217
 218         if (p > node_name) {
 219                 node = fdt_path_offset(blob, node_name);
 220                 if (node < 0) {
 221                         report_error(node_name, -1, node);
 222                         return -1;
 223                 }
 224         }
 225
 226         node = fdt_add_subnode(blob, node, p + 1);
 227         if (node < 0) {
 228                 report_error(p + 1, -1, node);
 229                 return -1;
 230         }
 231
 232         return 0;
 233 }
 234
 235 static int do_fdtput(struct display_info *disp, const char *filename,
 236                     char **arg, int arg_count)
 237 {
 238         char *value;
 239         char *blob;
 240         int len, ret = 0;
 241
 242         blob = utilfdt_read(filename);
 243         if (!blob)
 244                 return -1;
 245
 246         switch (disp->oper) {
 247         case OPER_WRITE_PROP:
 248                 /*
 249                  * Convert the arguments into a single binary value, then
 250                  * store them into the property.
 251                  */
 252                 assert(arg_count >= 2);
 253                 if (disp->auto_path && create_paths(blob, *arg))
 254                         return -1;
 255                 if (encode_value(disp, arg + 2, arg_count - 2, &value, &len) ||
 256                         store_key_value(blob, *arg, arg[1], value, len))
 257                         ret = -1;
 258                 break;
 259         case OPER_CREATE_NODE:
 260                 for (; ret >= 0 && arg_count--; arg++) {
 261                         if (disp->auto_path)
 262                                 ret = create_paths(blob, *arg);
 263                         else
 264                                 ret = create_node(blob, *arg);
 265                 }
 266                 break;
 267         }
 268         if (ret >= 0)
 269                 ret = utilfdt_write(filename, blob);
 270
 271         free(blob);
 272         return ret;
 273 }
 274
 275 static const char *usage_msg =
 276         "fdtput - write a property value to a device tree\n"
 277         "\n"
 278         "The command line arguments are joined together into a single value.\n"
 279         "\n"
 280         "Usage:\n"
 281         "       fdtput <options> <dt file> <node> <property> [<value>...]\n"
 282         "       fdtput -c <options> <dt file> [<node>...]\n"
 283         "Options:\n"
 284         "\t-c\t\tCreate nodes if they don't already exist\n"
 285         "\t-p\t\tAutomatically create nodes as needed for the node path\n"
 286         "\t-t <type>\tType of data\n"
 287         "\t-v\t\tVerbose: display each value decoded from command line\n"
 288         "\t-h\t\tPrint this help\n\n"
 289         USAGE_TYPE_MSG;
 290
 291 static void usage(const char *msg)
 292 {
 293         if (msg)
 294                 fprintf(stderr, "Error: %s\n\n", msg);
 295
 296         fprintf(stderr, "%s", usage_msg);
 297         exit(2);
 298 }
 299
 300 int main(int argc, char *argv[])
 301 {
 302         struct display_info disp;
 303         char *filename = NULL;
 304
 305         memset(&disp, '\0', sizeof(disp));
 306         disp.size = -1;
 307         disp.oper = OPER_WRITE_PROP;
 308         for (;;) {
 309                 int c = getopt(argc, argv, "chpt:v");
 310                 if (c == -1)
 311                         break;
 312
 313                 /*
 314                  * TODO: add options to:
 315                  * - delete property
 316                  * - delete node (optionally recursively)
 317                  * - rename node
 318                  * - pack fdt before writing
 319                  * - set amount of free space when writing
 320                  * - expand fdt if value doesn't fit
 321                  */
 322                 switch (c) {
 323                 case 'c':
 324                         disp.oper = OPER_CREATE_NODE;
 325                         break;
 326                 case 'h':
 327                 case '?':
 328                         usage(NULL);
 329                 case 'p':
 330                         disp.auto_path = 1;
 331                         break;
 332                 case 't':
 333                         if (utilfdt_decode_type(optarg, &disp.type,
 334                                         &disp.size))
 335                                 usage("Invalid type string");
 336                         break;
 337
 338                 case 'v':
 339                         disp.verbose = 1;
 340                         break;
 341                 }
 342         }
 343
 344         if (optind < argc)
 345                 filename = argv[optind++];
 346         if (!filename)
 347                 usage("Missing filename");
 348
 349         argv += optind;
 350         argc -= optind;
 351
 352         if (disp.oper == OPER_WRITE_PROP) {
 353                 if (argc < 1)
 354                         usage("Missing node");
 355                 if (argc < 2)
 356                         usage("Missing property");
 357         }
 358
 359         if (do_fdtput(&disp, filename, argv, argc))
 360                 return 1;
 361         return 0;
 362 }