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
report_error(const char * where,int err)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 */
show_data(struct display_info * disp,const char * data,int len)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 */
list_properties(const void * blob,int node)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 */
list_subnodes(const void * blob,int node)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 */
show_data_for_item(const void * blob,struct display_info * disp,int node,const char * property)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 */
do_fdtget(struct display_info * disp,const char * filename,char ** arg,int arg_count,int args_per_step)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
usage(const char * msg)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
main(int argc,char * argv[])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