xref: /linux/scripts/dtc/fdtoverlay.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) 2017 Konsulko Group Inc. All rights reserved.
4  *
5  * Author:
6  *	 Pantelis Antoniou <pantelis.antoniou@konsulko.com>
7  */
8 
9 #include <assert.h>
10 #include <ctype.h>
11 #include <getopt.h>
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <string.h>
15 #include <inttypes.h>
16 
17 #include <libfdt.h>
18 
19 #include "util.h"
20 
21 #define BUF_INCREMENT	65536
22 
23 /* Usage related data. */
24 static const char usage_synopsis[] =
25 	"apply a number of overlays to a base blob\n"
26 	"	fdtoverlay <options> [<overlay.dtbo> [<overlay.dtbo>]]";
27 static const char usage_short_opts[] = "i:o:v" USAGE_COMMON_SHORT_OPTS;
28 static struct option const usage_long_opts[] = {
29 	{"input",            required_argument, NULL, 'i'},
30 	{"output",	     required_argument, NULL, 'o'},
31 	{"verbose",	           no_argument, NULL, 'v'},
32 	USAGE_COMMON_LONG_OPTS,
33 };
34 static const char * const usage_opts_help[] = {
35 	"Input base DT blob",
36 	"Output DT blob",
37 	"Verbose messages",
38 	USAGE_COMMON_OPTS_HELP
39 };
40 
41 int verbose = 0;
42 
43 static void *apply_one(char *base, const char *overlay, size_t *buf_len,
44 		       const char *name)
45 {
46 	char *tmp = NULL;
47 	char *tmpo;
48 	int ret;
49 
50 	/*
51 	 * We take copies first, because a failed apply can trash
52 	 * both the base blob and the overlay
53 	 */
54 	tmpo = xmalloc(fdt_totalsize(overlay));
55 
56 	do {
57 		tmp = xrealloc(tmp, *buf_len);
58 		ret = fdt_open_into(base, tmp, *buf_len);
59 		if (ret) {
60 			fprintf(stderr,
61 				"\nFailed to make temporary copy: %s\n",
62 				fdt_strerror(ret));
63 			goto fail;
64 		}
65 
66 		memcpy(tmpo, overlay, fdt_totalsize(overlay));
67 
68 		ret = fdt_overlay_apply(tmp, tmpo);
69 		if (ret == -FDT_ERR_NOSPACE) {
70 			*buf_len += BUF_INCREMENT;
71 		}
72 	} while (ret == -FDT_ERR_NOSPACE);
73 
74 	if (ret) {
75 		fprintf(stderr, "\nFailed to apply '%s': %s\n",
76 			name, fdt_strerror(ret));
77 		goto fail;
78 	}
79 
80 	free(base);
81 	free(tmpo);
82 	return tmp;
83 
84 fail:
85 	free(tmpo);
86 	if (tmp)
87 		free(tmp);
88 
89 	return NULL;
90 }
91 static int do_fdtoverlay(const char *input_filename,
92 			 const char *output_filename,
93 			 int argc, char *argv[])
94 {
95 	char *blob = NULL;
96 	char **ovblob = NULL;
97 	size_t buf_len;
98 	int i, ret = -1;
99 
100 	blob = utilfdt_read(input_filename, &buf_len);
101 	if (!blob) {
102 		fprintf(stderr, "\nFailed to read '%s'\n", input_filename);
103 		goto out_err;
104 	}
105 	if (fdt_totalsize(blob) > buf_len) {
106 		fprintf(stderr,
107  "\nBase blob is incomplete (%lu / %" PRIu32 " bytes read)\n",
108 			(unsigned long)buf_len, fdt_totalsize(blob));
109 		goto out_err;
110 	}
111 
112 	/* allocate blob pointer array */
113 	ovblob = xmalloc(sizeof(*ovblob) * argc);
114 	memset(ovblob, 0, sizeof(*ovblob) * argc);
115 
116 	/* read and keep track of the overlay blobs */
117 	for (i = 0; i < argc; i++) {
118 		size_t ov_len;
119 		ovblob[i] = utilfdt_read(argv[i], &ov_len);
120 		if (!ovblob[i]) {
121 			fprintf(stderr, "\nFailed to read '%s'\n", argv[i]);
122 			goto out_err;
123 		}
124 		if (fdt_totalsize(ovblob[i]) > ov_len) {
125 			fprintf(stderr,
126 "\nOverlay '%s' is incomplete (%lu / %" PRIu32 " bytes read)\n",
127 				argv[i], (unsigned long)ov_len,
128 				fdt_totalsize(ovblob[i]));
129 			goto out_err;
130 		}
131 	}
132 
133 	buf_len = fdt_totalsize(blob);
134 
135 	/* apply the overlays in sequence */
136 	for (i = 0; i < argc; i++) {
137 		blob = apply_one(blob, ovblob[i], &buf_len, argv[i]);
138 		if (!blob)
139 			goto out_err;
140 	}
141 
142 	fdt_pack(blob);
143 	ret = utilfdt_write(output_filename, blob);
144 	if (ret)
145 		fprintf(stderr, "\nFailed to write '%s'\n",
146 			output_filename);
147 
148 out_err:
149 	if (ovblob) {
150 		for (i = 0; i < argc; i++) {
151 			if (ovblob[i])
152 				free(ovblob[i]);
153 		}
154 		free(ovblob);
155 	}
156 	free(blob);
157 
158 	return ret;
159 }
160 
161 int main(int argc, char *argv[])
162 {
163 	int opt, i;
164 	char *input_filename = NULL;
165 	char *output_filename = NULL;
166 
167 	while ((opt = util_getopt_long()) != EOF) {
168 		switch (opt) {
169 		case_USAGE_COMMON_FLAGS
170 
171 		case 'i':
172 			input_filename = optarg;
173 			break;
174 		case 'o':
175 			output_filename = optarg;
176 			break;
177 		case 'v':
178 			verbose = 1;
179 			break;
180 		}
181 	}
182 
183 	if (!input_filename)
184 		usage("missing input file");
185 
186 	if (!output_filename)
187 		usage("missing output file");
188 
189 	argv += optind;
190 	argc -= optind;
191 
192 	if (argc <= 0)
193 		usage("missing overlay file(s)");
194 
195 	if (verbose) {
196 		printf("input  = %s\n", input_filename);
197 		printf("output = %s\n", output_filename);
198 		for (i = 0; i < argc; i++)
199 			printf("overlay[%d] = %s\n", i, argv[i]);
200 	}
201 
202 	if (do_fdtoverlay(input_filename, output_filename, argc, argv))
203 		return 1;
204 
205 	return 0;
206 }
207