fdtoverlay: A tool that applies overlays

Since libfdt support overlay application on FDT blobs, provide
a command line tool that applies an arbitrary number of
overlays, one after another to a base fdt blob and output
the result in the given file.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Pantelis Antoniou 2017-06-14 17:51:11 +03:00 committed by David Gibson
parent aae22722fc
commit 42409146f2
4 changed files with 193 additions and 0 deletions

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@ -679,3 +679,17 @@ The syntax of the fdtdump command line is:
Where options are:
-d,--debug Dump debug information while decoding the file
-s,--scan Scan for an embedded fdt in given file
3) fdtoverlay -- Flat Device Tree overlay applicator
The fdtoverlay applies an arbitrary number of FDT overlays to a base FDT blob
to a given output file.
The syntax of the fdtoverlay command line is:
fdtoverlay -i <base-blob> -o <output-blob> <overlay-blob0> [<overlay-blob1> ...]
Where options are:
-i, --input Input base DT blob
-o, --output Output DT blob
-v, --verbose Verbose message output

View file

@ -120,6 +120,7 @@ BIN += dtc
BIN += fdtdump
BIN += fdtget
BIN += fdtput
BIN += fdtoverlay
SCRIPTS = dtdiff
@ -150,6 +151,7 @@ ifneq ($(DEPTARGETS),)
-include $(FDTDUMP_OBJS:%.o=%.d)
-include $(FDTGET_OBJS:%.o=%.d)
-include $(FDTPUT_OBJS:%.o=%.d)
-include $(FDTOVERLAY_OBJS:%.o=%.d)
endif
@ -226,6 +228,8 @@ fdtget: $(FDTGET_OBJS) $(LIBFDT_archive)
fdtput: $(FDTPUT_OBJS) $(LIBFDT_archive)
fdtoverlay: $(FDTOVERLAY_OBJS) $(LIBFDT_archive)
dist:
git archive --format=tar --prefix=dtc-$(dtc_version)/ HEAD \
> ../dtc-$(dtc_version).tar
@ -280,6 +284,7 @@ TESTS_BIN += convert-dtsv0
TESTS_BIN += fdtput
TESTS_BIN += fdtget
TESTS_BIN += fdtdump
TESTS_BIN += fdtoverlay
ifeq ($(NO_PYTHON),)
TESTS_PYLIBFDT += maybe_pylibfdt
endif

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@ -22,3 +22,9 @@ FDTPUT_SRCS = \
util.c
FDTPUT_OBJS = $(FDTPUT_SRCS:%.c=%.o)
FDTOVERLAY_SRCS = \
fdtoverlay.c \
util.c
FDTOVERLAY_OBJS = $(FDTOVERLAY_SRCS:%.c=%.o)

168
fdtoverlay.c Normal file
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@ -0,0 +1,168 @@
/*
* Copyright (c) 2017 Konsulko Group Inc. All rights reserved.
*
* Author:
* Pantelis Antoniou <pantelis.antoniou@konsulko.com>
*
* 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 <alloca.h>
#include <libfdt.h>
#include "util.h"
/* Usage related data. */
static const char usage_synopsis[] =
"apply a number of overlays to a base blob\n"
" fdtoverlay <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 DT blob",
"Output DT blob",
"Verbose messages",
USAGE_COMMON_OPTS_HELP
};
int verbose = 0;
static int do_fdtoverlay(const char *input_filename,
const char *output_filename,
int argc, char *argv[])
{
char *blob = NULL;
char **ovblob = NULL;
off_t blob_len, ov_len, total_len;
int i, ret = -1;
blob = utilfdt_read_len(input_filename, &blob_len);
if (!blob) {
fprintf(stderr, "\nFailed to read base blob %s\n",
input_filename);
goto out_err;
}
ret = 0;
/* allocate blob pointer array */
ovblob = alloca(sizeof(*ovblob) * argc);
memset(ovblob, 0, sizeof(*ovblob) * argc);
/* read and keep track of the overlay blobs */
total_len = 0;
for (i = 0; i < argc; i++) {
ovblob[i] = utilfdt_read_len(argv[i], &ov_len);
if (!ovblob[i]) {
fprintf(stderr, "\nFailed to read overlay %s\n",
argv[i]);
goto out_err;
}
total_len += ov_len;
}
/* grow the blob to worst case */
blob_len = fdt_totalsize(blob) + total_len;
blob = xrealloc(blob, blob_len);
fdt_open_into(blob, blob, blob_len);
/* apply the overlays in sequence */
for (i = 0; i < argc; i++) {
ret = fdt_overlay_apply(blob, ovblob[i]);
if (ret) {
fprintf(stderr, "\nFailed to apply %s (%d)\n",
argv[i], ret);
goto out_err;
}
}
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(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(input_filename, output_filename, argc, argv))
return 1;
return 0;
}