1 /* 2 * Copyright (c) 2011 The Chromium OS Authors. All rights reserved. 3 * 4 * Portions from U-Boot cmd_fdt.c (C) Copyright 2007 5 * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com 6 * Based on code written by: 7 * Pantelis Antoniou <pantelis.antoniou@gmail.com> and 8 * Matthew McClintock <msm@freescale.com> 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License as 12 * published by the Free Software Foundation; either version 2 of 13 * the License, or (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program; if not, write to the Free Software 22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 23 * MA 02111-1307 USA 24 */ 25 26 #include <assert.h> 27 #include <ctype.h> 28 #include <getopt.h> 29 #include <stdio.h> 30 #include <stdlib.h> 31 #include <string.h> 32 33 #include <libfdt.h> 34 35 #include "util.h" 36 37 enum display_mode { 38 MODE_SHOW_VALUE, /* show values for node properties */ 39 MODE_LIST_PROPS, /* list the properties for a node */ 40 MODE_LIST_SUBNODES, /* list the subnodes of a node */ 41 }; 42 43 /* Holds information which controls our output and options */ 44 struct display_info { 45 int type; /* data type (s/i/u/x or 0 for default) */ 46 int size; /* data size (1/2/4) */ 47 enum display_mode mode; /* display mode that we are using */ 48 const char *default_val; /* default value if node/property not found */ 49 }; 50 51 static void report_error(const char *where, int err) 52 { 53 fprintf(stderr, "Error at '%s': %s\n", where, fdt_strerror(err)); 54 } 55 56 /** 57 * Displays data of a given length according to selected options 58 * 59 * If a specific data type is provided in disp, then this is used. Otherwise 60 * we try to guess the data type / size from the contents. 61 * 62 * @param disp Display information / options 63 * @param data Data to display 64 * @param len Maximum length of buffer 65 * @return 0 if ok, -1 if data does not match format 66 */ 67 static int show_data(struct display_info *disp, const char *data, int len) 68 { 69 int i, size; 70 const uint8_t *p = (const uint8_t *)data; 71 const char *s; 72 int value; 73 int is_string; 74 char fmt[3]; 75 76 /* no data, don't print */ 77 if (len == 0) 78 return 0; 79 80 is_string = (disp->type) == 's' || 81 (!disp->type && util_is_printable_string(data, len)); 82 if (is_string) { 83 if (data[len - 1] != '\0') { 84 fprintf(stderr, "Unterminated string\n"); 85 return -1; 86 } 87 for (s = data; s - data < len; s += strlen(s) + 1) { 88 if (s != data) 89 printf(" "); 90 printf("%s", (const char *)s); 91 } 92 return 0; 93 } 94 size = disp->size; 95 if (size == -1) { 96 size = (len % 4) == 0 ? 4 : 1; 97 } else if (len % size) { 98 fprintf(stderr, "Property length must be a multiple of " 99 "selected data size\n"); 100 return -1; 101 } 102 fmt[0] = '%'; 103 fmt[1] = disp->type ? disp->type : 'd'; 104 fmt[2] = '\0'; 105 for (i = 0; i < len; i += size, p += size) { 106 if (i) 107 printf(" "); 108 value = size == 4 ? fdt32_to_cpu(*(const uint32_t *)p) : 109 size == 2 ? (*p << 8) | p[1] : *p; 110 printf(fmt, value); 111 } 112 return 0; 113 } 114 115 /** 116 * List all properties in a node, one per line. 117 * 118 * @param blob FDT blob 119 * @param node Node to display 120 * @return 0 if ok, or FDT_ERR... if not. 121 */ 122 static int list_properties(const void *blob, int node) 123 { 124 const struct fdt_property *data; 125 const char *name; 126 int prop; 127 128 prop = fdt_first_property_offset(blob, node); 129 do { 130 /* Stop silently when there are no more properties */ 131 if (prop < 0) 132 return prop == -FDT_ERR_NOTFOUND ? 0 : prop; 133 data = fdt_get_property_by_offset(blob, prop, NULL); 134 name = fdt_string(blob, fdt32_to_cpu(data->nameoff)); 135 if (name) 136 puts(name); 137 prop = fdt_next_property_offset(blob, prop); 138 } while (1); 139 } 140 141 #define MAX_LEVEL 32 /* how deeply nested we will go */ 142 143 /** 144 * List all subnodes in a node, one per line 145 * 146 * @param blob FDT blob 147 * @param node Node to display 148 * @return 0 if ok, or FDT_ERR... if not. 149 */ 150 static int list_subnodes(const void *blob, int node) 151 { 152 int nextoffset; /* next node offset from libfdt */ 153 uint32_t tag; /* current tag */ 154 int level = 0; /* keep track of nesting level */ 155 const char *pathp; 156 int depth = 1; /* the assumed depth of this node */ 157 158 while (level >= 0) { 159 tag = fdt_next_tag(blob, node, &nextoffset); 160 switch (tag) { 161 case FDT_BEGIN_NODE: 162 pathp = fdt_get_name(blob, node, NULL); 163 if (level <= depth) { 164 if (pathp == NULL) 165 pathp = "/* NULL pointer error */"; 166 if (*pathp == '\0') 167 pathp = "/"; /* root is nameless */ 168 if (level == 1) 169 puts(pathp); 170 } 171 level++; 172 if (level >= MAX_LEVEL) { 173 printf("Nested too deep, aborting.\n"); 174 return 1; 175 } 176 break; 177 case FDT_END_NODE: 178 level--; 179 if (level == 0) 180 level = -1; /* exit the loop */ 181 break; 182 case FDT_END: 183 return 1; 184 case FDT_PROP: 185 break; 186 default: 187 if (level <= depth) 188 printf("Unknown tag 0x%08X\n", tag); 189 return 1; 190 } 191 node = nextoffset; 192 } 193 return 0; 194 } 195 196 /** 197 * Show the data for a given node (and perhaps property) according to the 198 * display option provided. 199 * 200 * @param blob FDT blob 201 * @param disp Display information / options 202 * @param node Node to display 203 * @param property Name of property to display, or NULL if none 204 * @return 0 if ok, -ve on error 205 */ 206 static int show_data_for_item(const void *blob, struct display_info *disp, 207 int node, const char *property) 208 { 209 const void *value = NULL; 210 int len, err = 0; 211 212 switch (disp->mode) { 213 case MODE_LIST_PROPS: 214 err = list_properties(blob, node); 215 break; 216 217 case MODE_LIST_SUBNODES: 218 err = list_subnodes(blob, node); 219 break; 220 221 default: 222 assert(property); 223 value = fdt_getprop(blob, node, property, &len); 224 if (value) { 225 if (show_data(disp, value, len)) 226 err = -1; 227 else 228 printf("\n"); 229 } else if (disp->default_val) { 230 puts(disp->default_val); 231 } else { 232 report_error(property, len); 233 err = -1; 234 } 235 break; 236 } 237 238 return err; 239 } 240 241 /** 242 * Run the main fdtget operation, given a filename and valid arguments 243 * 244 * @param disp Display information / options 245 * @param filename Filename of blob file 246 * @param arg List of arguments to process 247 * @param arg_count Number of arguments 248 * @param return 0 if ok, -ve on error 249 */ 250 static int do_fdtget(struct display_info *disp, const char *filename, 251 char **arg, int arg_count, int args_per_step) 252 { 253 char *blob; 254 const char *prop; 255 int i, node; 256 257 blob = utilfdt_read(filename); 258 if (!blob) 259 return -1; 260 261 for (i = 0; i + args_per_step <= arg_count; i += args_per_step) { 262 node = fdt_path_offset(blob, arg[i]); 263 if (node < 0) { 264 if (disp->default_val) { 265 puts(disp->default_val); 266 continue; 267 } else { 268 report_error(arg[i], node); 269 return -1; 270 } 271 } 272 prop = args_per_step == 1 ? NULL : arg[i + 1]; 273 274 if (show_data_for_item(blob, disp, node, prop)) 275 return -1; 276 } 277 return 0; 278 } 279 280 static const char *usage_msg = 281 "fdtget - read values from device tree\n" 282 "\n" 283 "Each value is printed on a new line.\n\n" 284 "Usage:\n" 285 " fdtget <options> <dt file> [<node> <property>]...\n" 286 " fdtget -p <options> <dt file> [<node> ]...\n" 287 "Options:\n" 288 "\t-t <type>\tType of data\n" 289 "\t-p\t\tList properties for each node\n" 290 "\t-l\t\tList subnodes for each node\n" 291 "\t-d\t\tDefault value to display when the property is " 292 "missing\n" 293 "\t-h\t\tPrint this help\n\n" 294 USAGE_TYPE_MSG; 295 296 static void usage(const char *msg) 297 { 298 if (msg) 299 fprintf(stderr, "Error: %s\n\n", msg); 300 301 fprintf(stderr, "%s", usage_msg); 302 exit(2); 303 } 304 305 int main(int argc, char *argv[]) 306 { 307 char *filename = NULL; 308 struct display_info disp; 309 int args_per_step = 2; 310 311 /* set defaults */ 312 memset(&disp, '\0', sizeof(disp)); 313 disp.size = -1; 314 disp.mode = MODE_SHOW_VALUE; 315 for (;;) { 316 int c = getopt(argc, argv, "d:hlpt:"); 317 if (c == -1) 318 break; 319 320 switch (c) { 321 case 'h': 322 case '?': 323 usage(NULL); 324 325 case 't': 326 if (utilfdt_decode_type(optarg, &disp.type, 327 &disp.size)) 328 usage("Invalid type string"); 329 break; 330 331 case 'p': 332 disp.mode = MODE_LIST_PROPS; 333 args_per_step = 1; 334 break; 335 336 case 'l': 337 disp.mode = MODE_LIST_SUBNODES; 338 args_per_step = 1; 339 break; 340 341 case 'd': 342 disp.default_val = optarg; 343 break; 344 } 345 } 346 347 if (optind < argc) 348 filename = argv[optind++]; 349 if (!filename) 350 usage("Missing filename"); 351 352 argv += optind; 353 argc -= optind; 354 355 /* Allow no arguments, and silently succeed */ 356 if (!argc) 357 return 0; 358 359 /* Check for node, property arguments */ 360 if (args_per_step == 2 && (argc % 2)) 361 usage("Must have an even number of arguments"); 362 363 if (do_fdtget(&disp, filename, argv, argc, args_per_step)) 364 return 1; 365 return 0; 366 } 367