aboutsummaryrefslogtreecommitdiffstats
path: root/scripts/dtc/fdtput.c
blob: f2197f51930ba0cd81bef1e9aa6fd54948eb350d (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
/*
 * Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <assert.h>
#include <ctype.h>
#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <libfdt.h>

#include "util.h"

/* These are the operations we support */
enum oper_type {
	OPER_WRITE_PROP,		/* Write a property in a node */
	OPER_CREATE_NODE,		/* Create a new node */
};

struct display_info {
	enum oper_type oper;	/* operation to perform */
	int type;		/* data type (s/i/u/x or 0 for default) */
	int size;		/* data size (1/2/4) */
	int verbose;		/* verbose output */
	int auto_path;		/* automatically create all path components */
};


/**
 * Report an error with a particular node.
 *
 * @param name		Node name to report error on
 * @param namelen	Length of node name, or -1 to use entire string
 * @param err		Error number to report (-FDT_ERR_...)
 */
static void report_error(const char *name, int namelen, int err)
{
	if (namelen == -1)
		namelen = strlen(name);
	fprintf(stderr, "Error at '%1.*s': %s\n", namelen, name,
		fdt_strerror(err));
}

/**
 * Encode a series of arguments in a property value.
 *
 * @param disp		Display information / options
 * @param arg		List of arguments from command line
 * @param arg_count	Number of arguments (may be 0)
 * @param valuep	Returns buffer containing value
 * @param *value_len	Returns length of value encoded
 */
static int encode_value(struct display_info *disp, char **arg, int arg_count,
			char **valuep, int *value_len)
{
	char *value = NULL;	/* holding area for value */
	int value_size = 0;	/* size of holding area */
	char *ptr;		/* pointer to current value position */
	int len;		/* length of this cell/string/byte */
	int ival;
	int upto;	/* the number of bytes we have written to buf */
	char fmt[3];

	upto = 0;

	if (disp->verbose)
		fprintf(stderr, "Decoding value:\n");

	fmt[0] = '%';
	fmt[1] = disp->type ? disp->type : 'd';
	fmt[2] = '\0';
	for (; arg_count > 0; arg++, arg_count--, upto += len) {
		/* assume integer unless told otherwise */
		if (disp->type == 's')
			len = strlen(*arg) + 1;
		else
			len = disp->size == -1 ? 4 : disp->size;

		/* enlarge our value buffer by a suitable margin if needed */
		if (upto + len > value_size) {
			value_size = (upto + len) + 500;
			value = realloc(value, value_size);
			if (!value) {
				fprintf(stderr, "Out of mmory: cannot alloc "
					"%d bytes\n", value_size);
				return -1;
			}
		}

		ptr = value + upto;
		if (disp->type == 's') {
			memcpy(ptr, *arg, len);
			if (disp->verbose)
				fprintf(stderr, "\tstring: '%s'\n", ptr);
		} else {
			int *iptr = (int *)ptr;
			sscanf(*arg, fmt, &ival);
			if (len == 4)
				*iptr = cpu_to_fdt32(ival);
			else
				*ptr = (uint8_t)ival;
			if (disp->verbose) {
				fprintf(stderr, "\t%s: %d\n",
					disp->size == 1 ? "byte" :
					disp->size == 2 ? "short" : "int",
					ival);
			}
		}
	}
	*value_len = upto;
	*valuep = value;
	if (disp->verbose)
		fprintf(stderr, "Value size %d\n", upto);
	return 0;
}

static int store_key_value(void *blob, const char *node_name,
		const char *property, const char *buf, int len)
{
	int node;
	int err;

	node = fdt_path_offset(blob, node_name);
	if (node < 0) {
		report_error(node_name, -1, node);
		return -1;
	}

	err = fdt_setprop(blob, node, property, buf, len);
	if (err) {
		report_error(property, -1, err);
		return -1;
	}
	return 0;
}

/**
 * Create paths as needed for all components of a path
 *
 * Any components of the path that do not exist are created. Errors are
 * reported.
 *
 * @param blob		FDT blob to write into
 * @param in_path	Path to process
 * @return 0 if ok, -1 on error
 */
static int create_paths(void *blob, const char *in_path)
{
	const char *path = in_path;
	const char *sep;
	int node, offset = 0;

	/* skip leading '/' */
	while (*path == '/')
		path++;

	for (sep = path; *sep; path = sep + 1, offset = node) {
		/* equivalent to strchrnul(), but it requires _GNU_SOURCE */
		sep = strchr(path, '/');
		if (!sep)
			sep = path + strlen(path);

		node = fdt_subnode_offset_namelen(blob, offset, path,
				sep - path);
		if (node == -FDT_ERR_NOTFOUND) {
			node = fdt_add_subnode_namelen(blob, offset, path,
						       sep - path);
		}
		if (node < 0) {
			report_error(path, sep - path, node);
			return -1;
		}
	}

	return 0;
}

/**
 * Create a new node in the fdt.
 *
 * This will overwrite the node_name string. Any error is reported.
 *
 * TODO: Perhaps create fdt_path_offset_namelen() so we don't need to do this.
 *
 * @param blob		FDT blob to write into
 * @param node_name	Name of node to create
 * @return new node offset if found, or -1 on failure
 */
static int create_node(void *blob, const char *node_name)
{
	int node = 0;
	char *p;

	p = strrchr(node_name, '/');
	if (!p) {
		report_error(node_name, -1, -FDT_ERR_BADPATH);
		return -1;
	}
	*p = '\0';

	if (p > node_name) {
		node = fdt_path_offset(blob, node_name);
		if (node < 0) {
			report_error(node_name, -1, node);
			return -1;
		}
	}

	node = fdt_add_subnode(blob, node, p + 1);
	if (node < 0) {
		report_error(p + 1, -1, node);
		return -1;
	}

	return 0;
}

static int do_fdtput(struct display_info *disp, const char *filename,
		    char **arg, int arg_count)
{
	char *value;
	char *blob;
	int len, ret = 0;

	blob = utilfdt_read(filename);
	if (!blob)
		return -1;

	switch (disp->oper) {
	case OPER_WRITE_PROP:
		/*
		 * Convert the arguments into a single binary value, then
		 * store them into the property.
		 */
		assert(arg_count >= 2);
		if (disp->auto_path && create_paths(blob, *arg))
			return -1;
		if (encode_value(disp, arg + 2, arg_count - 2, &value, &len) ||
			store_key_value(blob, *arg, arg[1], value, len))
			ret = -1;
		break;
	case OPER_CREATE_NODE:
		for (; ret >= 0 && arg_count--; arg++) {
			if (disp->auto_path)
				ret = create_paths(blob, *arg);
			else
				ret = create_node(blob, *arg);
		}
		break;
	}
	if (ret >= 0)
		ret = utilfdt_write(filename, blob);

	free(blob);
	return ret;
}

static const char *usage_msg =
	"fdtput - write a property value to a device tree\n"
	"\n"
	"The command line arguments are joined together into a single value.\n"
	"\n"
	"Usage:\n"
	"	fdtput <options> <dt file> <node> <property> [<value>...]\n"
	"	fdtput -c <options> <dt file> [<node>...]\n"
	"Options:\n"
	"\t-c\t\tCreate nodes if they don't already exist\n"
	"\t-p\t\tAutomatically create nodes as needed for the node path\n"
	"\t-t <type>\tType of data\n"
	"\t-v\t\tVerbose: display each value decoded from command line\n"
	"\t-h\t\tPrint this help\n\n"
	USAGE_TYPE_MSG;

static void usage(const char *msg)
{
	if (msg)
		fprintf(stderr, "Error: %s\n\n", msg);

	fprintf(stderr, "%s", usage_msg);
	exit(2);
}

int main(int argc, char *argv[])
{
	struct display_info disp;
	char *filename = NULL;

	memset(&disp, '\0', sizeof(disp));
	disp.size = -1;
	disp.oper = OPER_WRITE_PROP;
	for (;;) {
		int c = getopt(argc, argv, "chpt:v");
		if (c == -1)
			break;

		/*
		 * TODO: add options to:
		 * - delete property
		 * - delete node (optionally recursively)
		 * - rename node
		 * - pack fdt before writing
		 * - set amount of free space when writing
		 * - expand fdt if value doesn't fit
		 */
		switch (c) {
		case 'c':
			disp.oper = OPER_CREATE_NODE;
			break;
		case 'h':
		case '?':
			usage(NULL);
		case 'p':
			disp.auto_path = 1;
			break;
		case 't':
			if (utilfdt_decode_type(optarg, &disp.type,
					&disp.size))
				usage("Invalid type string");
			break;

		case 'v':
			disp.verbose = 1;
			break;
		}
	}

	if (optind < argc)
		filename = argv[optind++];
	if (!filename)
		usage("Missing filename");

	argv += optind;
	argc -= optind;

	if (disp.oper == OPER_WRITE_PROP) {
		if (argc < 1)
			usage("Missing node");
		if (argc < 2)
			usage("Missing property");
	}

	if (do_fdtput(&disp, filename, argv, argc))
		return 1;
	return 0;
}