Browse Source
This simply utility makes it easy for scripts to read values from the device tree. It is written in C and uses the same libfdt as the rest of the dtc package. What is it for: - Reading fdt values from scripts - Extracting fdt information within build systems - Looking at particular values without having to dump the entire tree To use it, specify the fdt binary file on command line followed by a list of node, property pairs. The utility then looks up each node, finds the property and displays the value. Each value is printed on a new line. fdtget tries to guess the type of each property based on its contents. This is not always reliable, so you can use the -t option to force fdtget to decode the value as a string, or byte, etc. To read from stdin, use - as the file. Usage: fdtget <options> <dt file> [<node> <property>]... Options: -t <type> Type of data -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) Signed-off-by: Simon Glass <sjg@chromium.org>main
Simon Glass
13 years ago
committed by
Jon Loeliger
8 changed files with 326 additions and 1 deletions
@ -0,0 +1,226 @@
@@ -0,0 +1,226 @@
|
||||
/* |
||||
* 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 <ctype.h> |
||||
#include <getopt.h> |
||||
#include <stdio.h> |
||||
#include <stdlib.h> |
||||
#include <string.h> |
||||
|
||||
#include <libfdt.h> |
||||
|
||||
#include "util.h" |
||||
|
||||
/* Holds information which controls our output and options */ |
||||
struct display_info { |
||||
int type; /* data type (s/i/u/x or 0 for default) */ |
||||
int size; /* data size (1/2/4) */ |
||||
}; |
||||
|
||||
static void report_error(const char *where, int err) |
||||
{ |
||||
fprintf(stderr, "Error at '%s': %s\n", where, fdt_strerror(err)); |
||||
} |
||||
|
||||
/** |
||||
* Displays data of a given length according to selected options |
||||
* |
||||
* If a specific data type is provided in disp, then this is used. Otherwise |
||||
* we try to guess the data type / size from the contents. |
||||
* |
||||
* @param disp Display information / options |
||||
* @param data Data to display |
||||
* @param len Maximum length of buffer |
||||
* @return 0 if ok, -1 if data does not match format |
||||
*/ |
||||
static int show_data(struct display_info *disp, const char *data, int len) |
||||
{ |
||||
int i, size; |
||||
const uint8_t *p = (const uint8_t *)data; |
||||
const char *s; |
||||
int value; |
||||
int is_string; |
||||
char fmt[3]; |
||||
|
||||
/* no data, don't print */ |
||||
if (len == 0) |
||||
return 0; |
||||
|
||||
is_string = (disp->type) == 's' || |
||||
(!disp->type && util_is_printable_string(data, len)); |
||||
if (is_string) { |
||||
if (data[len - 1] != '\0') { |
||||
fprintf(stderr, "Unterminated string\n"); |
||||
return -1; |
||||
} |
||||
for (s = data; s - data < len; s += strlen(s) + 1) { |
||||
if (s != data) |
||||
printf(" "); |
||||
printf("%s", (const char *)s); |
||||
} |
||||
return 0; |
||||
} |
||||
size = disp->size; |
||||
if (size == -1) |
||||
size = (len % 4) == 0 ? 4 : 1; |
||||
else if (len % size) { |
||||
fprintf(stderr, "Property length must be a multiple of " |
||||
"selected data size\n"); |
||||
return -1; |
||||
} |
||||
fmt[0] = '%'; |
||||
fmt[1] = disp->type ? disp->type : 'd'; |
||||
fmt[2] = '\0'; |
||||
for (i = 0; i < len; i += size, p += size) { |
||||
if (i) |
||||
printf(" "); |
||||
value = size == 4 ? fdt32_to_cpu(*(const uint32_t *)p) : |
||||
size == 2 ? (*p << 8) | p[1] : *p; |
||||
printf(fmt, value); |
||||
} |
||||
return 0; |
||||
} |
||||
|
||||
/** |
||||
* Show the data for a given node (and perhaps property) according to the |
||||
* display option provided. |
||||
* |
||||
* @param blob FDT blob |
||||
* @param disp Display information / options |
||||
* @param node Node to display |
||||
* @param property Name of property to display, or NULL if none |
||||
* @return 0 if ok, -ve on error |
||||
*/ |
||||
static int show_data_for_item(const void *blob, struct display_info *disp, |
||||
int node, const char *property) |
||||
{ |
||||
const void *value = NULL; |
||||
int len, err = 0; |
||||
|
||||
value = fdt_getprop(blob, node, property, &len); |
||||
if (value) { |
||||
if (show_data(disp, value, len)) |
||||
err = -1; |
||||
else |
||||
printf("\n"); |
||||
} else { |
||||
report_error(property, len); |
||||
err = -1; |
||||
} |
||||
return err; |
||||
} |
||||
|
||||
/** |
||||
* Run the main fdtget operation, given a filename and valid arguments |
||||
* |
||||
* @param disp Display information / options |
||||
* @param filename Filename of blob file |
||||
* @param arg List of arguments to process |
||||
* @param arg_count Number of arguments |
||||
* @param return 0 if ok, -ve on error |
||||
*/ |
||||
static int do_fdtget(struct display_info *disp, const char *filename, |
||||
char **arg, int arg_count) |
||||
{ |
||||
char *blob; |
||||
int i, node; |
||||
|
||||
blob = utilfdt_read(filename); |
||||
if (!blob) |
||||
return -1; |
||||
|
||||
for (i = 0; i + 2 <= arg_count; i += 2) { |
||||
node = fdt_path_offset(blob, arg[0]); |
||||
if (node < 0) { |
||||
report_error(arg[0], node); |
||||
return -1; |
||||
} |
||||
|
||||
if (show_data_for_item(blob, disp, node, arg[1])) |
||||
return -1; |
||||
} |
||||
return 0; |
||||
} |
||||
|
||||
static const char *usage_msg = |
||||
"fdtget - read values from device tree\n" |
||||
"\n" |
||||
"Each value is printed on a new line.\n\n" |
||||
"Usage:\n" |
||||
" fdtget <options> <dt file> [<node> <property>]...\n" |
||||
"Options:\n" |
||||
"\t-t <type>\tType of data\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[]) |
||||
{ |
||||
char *filename = NULL; |
||||
struct display_info disp; |
||||
|
||||
/* set defaults */ |
||||
memset(&disp, '\0', sizeof(disp)); |
||||
disp.size = -1; |
||||
for (;;) { |
||||
int c = getopt(argc, argv, "ht:"); |
||||
if (c == -1) |
||||
break; |
||||
|
||||
switch (c) { |
||||
case 'h': |
||||
case '?': |
||||
usage(NULL); |
||||
|
||||
case 't': |
||||
if (utilfdt_decode_type(optarg, &disp.type, |
||||
&disp.size)) |
||||
usage("Invalid type string"); |
||||
break; |
||||
} |
||||
} |
||||
|
||||
if (optind < argc) |
||||
filename = argv[optind++]; |
||||
if (!filename) |
||||
usage("Missing filename"); |
||||
|
||||
argv += optind; |
||||
argc -= optind; |
||||
|
||||
/* Allow no arguments, and silently succeed */ |
||||
if (!argc) |
||||
return 0; |
||||
|
||||
/* Check for node, property arguments */ |
||||
if (argc % 2) |
||||
usage("Must have an even number of arguments"); |
||||
|
||||
if (do_fdtget(&disp, filename, argv, argc)) |
||||
return 1; |
||||
return 0; |
||||
} |
||||
@ -0,0 +1,35 @@
@@ -0,0 +1,35 @@
|
||||
#! /bin/sh |
||||
|
||||
. ./tests.sh |
||||
|
||||
LOG="tmp.log.$$" |
||||
EXPECT="tmp.expect.$$" |
||||
|
||||
rm -f $TMPFILE $LOG |
||||
|
||||
expect="$1" |
||||
echo "$expect" >$EXPECT |
||||
shift |
||||
|
||||
verbose_run_log "$LOG" $VALGRIND "$DTGET" "$@" |
||||
ret="$?" |
||||
|
||||
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 |
||||
|
||||
diff $EXPECT $LOG |
||||
ret="$?" |
||||
|
||||
rm -f $LOG $EXPECT |
||||
|
||||
if [ "$ret" -eq 0 ]; then |
||||
PASS |
||||
else |
||||
FAIL |
||||
fi |
||||
Loading…
Reference in new issue