fdtoverlaymerge: A tool that merges overlays
fdtoverlaymerge is a command-line tool that merges two or more overlay blobs
by making use of fdt_overlay_merge() API
Change-Id: Idcd46e630436681a4bc640e7b53bc225cf5e4287
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
Signed-off-by: Rama Aparna Mallavarapu <aparnam@codeaurora.org>
diff --git a/Makefile b/Makefile
index 7fe25f6..b936fae 100644
--- a/Makefile
+++ b/Makefile
@@ -148,6 +148,7 @@
BIN += fdtget
BIN += fdtput
BIN += fdtoverlay
+BIN += fdtoverlaymerge
SCRIPTS = dtdiff
@@ -274,6 +275,8 @@
fdtoverlay: $(FDTOVERLAY_OBJS) $(LIBFDT_dep)
+fdtoverlaymerge: $(FDTOVERLAYMERGE_OBJS) $(LIBFDT_archive)
+
dist:
git archive --format=tar --prefix=dtc-$(dtc_version)/ HEAD \
> ../dtc-$(dtc_version).tar
diff --git a/Makefile.utils b/Makefile.utils
index 9436b34..e24a8ab 100644
--- a/Makefile.utils
+++ b/Makefile.utils
@@ -29,3 +29,9 @@
util.c
FDTOVERLAY_OBJS = $(FDTOVERLAY_SRCS:%.c=%.o)
+
+FDTOVERLAYMERGE_SRCS = \
+ fdtoverlaymerge.c \
+ util.c
+
+FDTOVERLAYMERGE_OBJS = $(FDTOVERLAYMERGE_SRCS:%.c=%.o)
diff --git a/fdtoverlaymerge.c b/fdtoverlaymerge.c
new file mode 100644
index 0000000..57631e3
--- /dev/null
+++ b/fdtoverlaymerge.c
@@ -0,0 +1,221 @@
+/* Copyright (c) 2018, The Linux Foundation. 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 version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#include <assert.h>
+#include <ctype.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <inttypes.h>
+
+#include <libfdt.h>
+
+#include "util.h"
+
+/* Usage related data. */
+static const char usage_synopsis[] =
+ "merge a number of overlays\n"
+ " fdtoverlaymerge <options> [<overlay.dtbo> [<overlay.dtbo>]]\n"
+ "\n"
+ USAGE_TYPE_MSG;
+static const char usage_short_opts[] = "i:o:v" USAGE_COMMON_SHORT_OPTS;
+static struct option const usage_long_opts[] = {
+ {"input", required_argument, NULL, 'i'},
+ {"output", required_argument, NULL, 'o'},
+ {"verbose", no_argument, NULL, 'v'},
+ USAGE_COMMON_LONG_OPTS,
+};
+static const char * const usage_opts_help[] = {
+ "Input base overlay DT blob",
+ "Output DT blob",
+ "Verbose messages",
+ USAGE_COMMON_OPTS_HELP
+};
+
+int verbose = 0;
+
+static void grow_blob(char **blob, off_t extra_len)
+{
+ int blob_len;
+
+ if (!extra_len)
+ return;
+
+ blob_len = fdt_totalsize(*blob) + extra_len;
+ *blob = xrealloc(*blob, blob_len);
+ fdt_open_into(*blob, *blob, blob_len);
+}
+
+static int reload_blob(char *filename, char **blob, off_t extra_len)
+{
+ free(*blob);
+ *blob = utilfdt_read(filename, NULL);
+ if (!*blob) {
+ fprintf(stderr, "Failed to reload blob %s\n", filename);
+ return -1;
+ }
+
+ grow_blob(blob, extra_len);
+
+ return 0;
+}
+
+static int do_fdtoverlay_merge(const char *input_filename,
+ const char *output_filename,
+ int argc, char *argv[])
+{
+ char *blob = NULL;
+ char **ovblob = NULL;
+ size_t ov_len, blob_len, total_len, extra_blob_len = 0;
+ size_t *extra_ov_len;
+ int i, ret = -1;
+
+ /* allocate blob pointer array */
+ ovblob = xmalloc(sizeof(*ovblob) * argc);
+ memset(ovblob, 0, sizeof(*ovblob) * argc);
+
+ extra_ov_len = xmalloc(sizeof(*extra_ov_len) * argc);
+ memset(extra_ov_len, 0, sizeof(*extra_ov_len) * argc);
+
+reload_all_blobs:
+ /* Free existing buffer first */
+ free(blob);
+ blob = utilfdt_read(input_filename, &blob_len);
+ if (!blob) {
+ fprintf(stderr, "\nFailed to read base blob %s\n",
+ input_filename);
+ goto out_err;
+ }
+ if (fdt_totalsize(blob) > blob_len) {
+ fprintf(stderr,
+ "\nBase blob is incomplete (%lu / %" PRIu32 " bytes read)\n",
+ (unsigned long)blob_len, fdt_totalsize(blob));
+ goto out_err;
+ }
+ ret = 0;
+
+ /* read and keep track of the overlay blobs */
+ total_len = extra_blob_len;
+ for (i = 0; i < argc; i++) {
+ /* Free existing buffer first */
+ free(ovblob[i]);
+ ovblob[i] = utilfdt_read(argv[i], &ov_len);
+ if (!ovblob[i]) {
+ fprintf(stderr, "\nFailed to read overlay %s\n",
+ argv[i]);
+ goto out_err;
+ }
+ grow_blob(&ovblob[i], extra_ov_len[i]);
+ total_len += ov_len + extra_ov_len[i];
+ }
+
+ /* grow the blob to worst case */
+ grow_blob(&blob, total_len);
+
+ /* apply the overlays in sequence */
+ for (i = 0; i < argc; i++) {
+ do {
+ int fdto_nospace;
+
+ fprintf(stderr, "Merging overlay blob %s\n", argv[i]);
+ ret = fdt_overlay_merge(blob, ovblob[i], &fdto_nospace);
+ if (ret && ret == -FDT_ERR_NOSPACE) {
+ if (fdto_nospace) {
+ extra_ov_len[i] += 512;
+ fprintf(stderr, "Reloading overlay blob %s\n", argv[i]);
+ ret = reload_blob(argv[i], &ovblob[i], extra_ov_len[i]);
+ if (!ret)
+ continue;
+ } else {
+ extra_blob_len += 512;
+ fprintf(stderr, "Reloading all blobs\n");
+ goto reload_all_blobs;
+ }
+ }
+
+ if (!ret)
+ break;
+
+ if (ret) {
+ fprintf(stderr, "\nFailed to merge %s (%d)\n",
+ argv[i], ret);
+ goto out_err;
+ }
+ } while (1);
+ }
+
+ fdt_pack(blob);
+ ret = utilfdt_write(output_filename, blob);
+ if (ret)
+ fprintf(stderr, "\nFailed to write output blob %s\n",
+ output_filename);
+
+out_err:
+ if (ovblob) {
+ for (i = 0; i < argc; i++) {
+ if (ovblob[i])
+ free(ovblob[i]);
+ }
+ free(ovblob);
+ }
+ free(blob);
+
+ return ret;
+}
+
+int main(int argc, char *argv[])
+{
+ int opt, i;
+ char *input_filename = NULL;
+ char *output_filename = NULL;
+
+ while ((opt = util_getopt_long()) != EOF) {
+ switch (opt) {
+ case_USAGE_COMMON_FLAGS
+
+ case 'i':
+ input_filename = optarg;
+ break;
+ case 'o':
+ output_filename = optarg;
+ break;
+ case 'v':
+ verbose = 1;
+ break;
+ }
+ }
+
+ if (!input_filename)
+ usage("missing input file");
+
+ if (!output_filename)
+ usage("missing output file");
+
+ argv += optind;
+ argc -= optind;
+
+ if (argc <= 0)
+ usage("missing overlay file(s)");
+
+ if (verbose) {
+ printf("input = %s\n", input_filename);
+ printf("output = %s\n", output_filename);
+ for (i = 0; i < argc; i++)
+ printf("overlay[%d] = %s\n", i, argv[i]);
+ }
+
+ if (do_fdtoverlay_merge(input_filename, output_filename, argc, argv))
+ return 1;
+
+ return 0;
+}