Add fdtput utility to write property values to a device tree

This simple utility allows writing of values into a device tree from the
command line. It aimes to be the opposite of fdtget.

What is it for:
- Updating fdt values when a binary blob already exists
   (even though source may be available it might be easier to use this
    utility rather than sed, etc.)
- Writing machine-specific fdt values within a build system

To use it, specify the fdt binary file on command line followed by the node
and property to set. Then, provide a list of values to put into that
property. Often there will be just one, but fdtput also supports arrays and
string lists.

fdtput does not try to guess the type of the property based on looking at
the arguments. Instead it always assumes that an integer is provided. To
indicate that you want to write a string, use -ts. You can also provide
hex values with -tx.

The command line arguments are joined together into a single value. For
strings, a nul terminator is placed between each string when it is packed
into the property. To avoid this, pass the string as a single argument.

Usage:
	fdtput <options> <dt file> <<node> <property> [<value>...]
Options:
	-t <type>	Type of data
	-v		Verbose: display each value decoded from command line
	-h		Print this help

<type>	s=string, i=int, u=unsigned, x=hex
	Optional modifier prefix:
		hh or b=byte, h=2 byte, l=4 byte (default)

To read from stdin and write to stdout, use - as the file. So you can do:

cat somefile.dtb | fdtput -ts - /node prop "My string value" > newfile.dtb

This commit also adds basic tests to verify the major features.

Signed-off-by: Simon Glass <sjg@chromium.org>

.gitignore

@@ -11,3 +11,4 @@ lex.yy.c
 /convert-dtsv0
 /version_gen.h
 /fdtget
+/fdtput

Makefile

@@ -111,6 +111,7 @@ BIN += convert-dtsv0
 BIN += dtc
 BIN += fdtdump
 BIN += fdtget
+BIN += fdtput
 
 SCRIPTS = dtdiff
 
@@ -122,6 +123,7 @@ ifneq ($(DEPTARGETS),)
 -include $(CONVERT_OBJS:%.o=%.d)
 -include $(FDTDUMP_OBJS:%.o=%.d)
 -include $(FDTGET_OBJS:%.o=%.d)
+-include $(FDTPUT_OBJS:%.o=%.d)
 endif
 
 
@@ -184,6 +186,8 @@ fdtdump:	$(FDTDUMP_OBJS)
 
 fdtget:	$(FDTGET_OBJS) $(LIBFDT_archive)
 
+fdtput:	$(FDTPUT_OBJS) $(LIBFDT_archive)
+
 
 #
 # Testsuite rules

Makefile.utils

@@ -15,3 +15,10 @@ FDTGET_SRCS = \
 	util.c
 
 FDTGET_OBJS = $(FDTGET_SRCS:%.c=%.o)
+
+
+FDTPUT_SRCS = \
+	fdtput.c \
+	util.c
+
+FDTPUT_OBJS = $(FDTPUT_SRCS:%.c=%.o)

fdtput.c

@@ -0,0 +1,235 @@
+/*
+ * 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"
+
+struct display_info {
+	int type;		/* data type (s/i/u/x or 0 for default) */
+	int size;		/* data size (1/2/4) */
+	int verbose;		/* verbose output */
+};
+
+static void report_error(const char *where, int err)
+{
+	fprintf(stderr, "Error at '%s': %s\n", where, 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, node);
+		return -1;
+	}
+
+	err = fdt_setprop(blob, node, property, buf, len);
+	if (err) {
+		report_error(property, err);
+		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;
+
+	/* convert the arguments into a single binary value, then store */
+	assert(arg_count >= 2);
+	if (encode_value(disp, arg + 2, arg_count - 2, &value, &len) ||
+		store_key_value(blob, *arg, arg[1], value, len))
+		ret = -1;
+
+	if (!ret)
+		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"
+	"Options:\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;
+	for (;;) {
+		int c = getopt(argc, argv, "ht: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 'h':
+		case '?':
+			usage(NULL);
+
+		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 (argc < 1)
+		usage("Missing node");
+	if (argc < 2)
+		usage("Missing property");
+
+	if (do_fdtput(&disp, filename, argv, argc))
+		return 1;
+	return 0;
+}

tests/fdtput-runtest.sh

@@ -0,0 +1,55 @@
+#! /bin/sh
+
+# Run script for fdtput tests
+# We run fdtput to update the device tree, thn fdtget to check it
+
+# Usage
+#    fdtput-runtest.sh name expected_output dtb_file node property flags value
+
+. ./tests.sh
+
+LOG="tmp.log.$$"
+EXPECT="tmp.expect.$$"
+
+rm -f $TMPFILE $LOG
+
+expect="$1"
+echo "$expect" >$EXPECT
+dtb="$2"
+node="$3"
+property="$4"
+flags="$5"
+shift 5
+value="$@"
+
+# First run fdtput
+verbose_run $VALGRIND "$DTPUT" "$dtb" "$node" "$property" $value $flags
+ret="$?"
+
+if [ "$ret" -ne 0 -a "$expect" = "ERR" ]; then
+	PASS
+fi
+if [ "$ret" -gt 127 ]; then
+    signame=$(kill -l $[ret - 128])
+    FAIL "Killed by SIG$signame"
+fi
+
+# Now fdtget to read the value
+verbose_run_log "$LOG" $VALGRIND "$DTGET" "$dtb" "$node" "$property" $flags
+ret="$?"
+
+if [ "$ret" -gt 127 ]; then
+    signame=$(kill -l $[ret - 128])
+    FAIL "Killed by SIG$signame"
+fi
+
+diff $EXPECT $LOG
+ret="$?"
+
+rm -f $LOG $EXPECT
+
+if [ "$ret" -eq 0 ]; then
+	PASS
+else
+	FAIL
+fi

tests/run_tests.sh

@@ -90,6 +90,21 @@ run_fdtget_test () {
     base_run_test sh fdtget-runtest.sh "$@"
 }
 
+run_fdtput_test () {
+    # run_fdtput_test name expected_output dtb_file node property flags value...
+    echo -n "$1:	"
+    shift
+    output="$1"
+    dtb="$2"
+    node="$3"
+    property="$4"
+    flags="$5"
+    shift 5
+    base_run_test sh fdtput-runtest.sh "$output" "$dtb" "$node" "$property" \
+		"$flags" $@
+#     base_run_test sh fdtput-runtest.sh "$@"
+}
+
 tree1_tests () {
     TREE=$1
 
@@ -440,6 +455,59 @@ fdtget_tests () {
 	$file /randomnode doctor-who
 }
 
+fdtput_tests () {
+    file=label01.dtb
+    src=label01.dts
+
+    # Create some test files containing useful strings
+    base=tmp.test0
+    file1=tmp.test1
+    file2=tmp.test2
+    bigfile1=tmp.test3
+    bigfile2=tmp.test4
+
+    # Filter out anything the shell might not like
+    cat $src | tr -d "'\"\n\;/\.\*{}\-" | tr -s "[:blank:]" " " >$base
+
+    # Make two small files
+    head -5 $base >$file1
+    cat $file1 | tr a-z A-Z | cut -c10-30 | sort -r >$file2
+
+    # and two larger ones
+    cat $base > $bigfile1
+    tac $base | tr a-z A-Z | sort -r >$bigfile2
+
+    # Allow just enough space for both file1 and file2
+    (( space = $(stat -c %s $file1) + $(stat -c %s $file2) ))
+    $DTC -O dtb -p $space -o $file ${file%.dtb}.dts 2>/dev/null
+
+    # run_fdtput_test <test-name> <expected-result> <file> <key> <flags>
+    #		<args>...
+    run_fdtput_test "Simple string" "a_model" $file / model -ts "a_model"
+    run_fdtput_test "Multiple string s" "board1 board2" \
+	$file / compatible -ts board1 board2
+    run_fdtput_test "Single string with spaces" "board1 board2" \
+	$file / compatible -ts "board1 board2"
+    run_fdtput_test "Integer" "32768" \
+	$file /cpus/PowerPC,970@1 d-cache-size "" "32768"
+    run_fdtput_test "Integer hex" "8001" \
+	$file /cpus/PowerPC,970@1 d-cache-size -tx 0x8001
+    run_fdtput_test "Integer list" "2 3 12" \
+	$file /randomnode tricky1 -tbi "02 003 12"
+    run_fdtput_test "Byte list short" "a b c ea ad be ef" \
+	$file /randomnode blob -tbx "a b c ea ad be ef"
+    run_fdtput_test "Integer list short" "a0b0c0d deeaae ef000000" \
+	$file /randomnode blob -tx "a0b0c0d deeaae ef000000"
+    run_fdtput_test "Large string list" "`cat $file1 $file2`" \
+	$file /randomnode blob -ts "`cat $file1`" "`cat $file2`"
+
+    # This should be larger than available space in the fdt ($space)
+    run_fdtput_test "Enormous string list" ERR \
+	$file /randomnode blob -ts "`cat $bigfile1`" "`cat $bigfile2`"
+
+    # TODO: Add tests for verbose mode?
+}
+
 utilfdt_tests () {
     run_test utilfdt_test
 }
@@ -459,7 +527,7 @@ while getopts "vt:m" ARG ; do
 done
 
 if [ -z "$TESTSETS" ]; then
-    TESTSETS="libfdt utilfdt dtc dtbs_equal fdtget"
+    TESTSETS="libfdt utilfdt dtc dtbs_equal fdtget fdtput"
 fi
 
 # Make sure we don't have stale blobs lying around
@@ -482,6 +550,9 @@ for set in $TESTSETS; do
 	"fdtget")
 	    fdtget_tests
 	    ;;
+	"fdtput")
+	    fdtput_tests
+	    ;;
     esac
 done
 

tests/tests.sh

@@ -12,6 +12,7 @@ FAIL () {
 
 DTC=../dtc
 DTGET=../fdtget
+DTPUT=../fdtput
 
 verbose_run () {
     if [ -z "$QUIET_TEST" ]; then