u-boot/tools/env/fw_env_main.c
Michael Heimpold 9884f44cab tools/env: allow config filename to be passed via command line argument
When for example generating/manipulating SD card/eMMC images which
contain U-Boot and its environment(s), it is handy to use a given
configuration file instead of the compiled-in default one.
And since the default configuration file is expected under /etc
it's hard for an usual linux user account without special permissions
to use fw_printenv/fw_setenv for this purpose.
So allow to pass an optional filename via a new '-c' command
line argument.

Example:

$ ln -s fw_printenv tools/env/fw_setenv
$ cat fw_env.config
test.img 0x20000 0x20000
test.img 0x40000 0x20000

$ tools/env/fw_printenv -c ./fw_env.config fdt_file
fdt_file=imx28-duckbill.dtb

$ tools/env/fw_setenv -c ./fw_env.config fdt_file imx28-duckbill-spi.dtb

$ tools/env/fw_printenv -c ./fw_env.config fdt_file
fdt_file=imx28-duckbill-spi.dtb

Signed-off-by: Michael Heimpold <mhei@heimpold.de>
2015-11-18 08:47:02 -05:00

155 lines
4 KiB
C

/*
* (C) Copyright 2000-2008
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* SPDX-License-Identifier: GPL-2.0+
*/
/*
* Command line user interface to firmware (=U-Boot) environment.
*
* Implements:
* fw_printenv [ -a key ] [[ -n name ] | [ name ... ]]
* - prints the value of a single environment variable
* "name", the ``name=value'' pairs of one or more
* environment variables "name", or the whole
* environment if no names are specified.
* fw_setenv [ -a key ] name [ value ... ]
* - If a name without any values is given, the variable
* with this name is deleted from the environment;
* otherwise, all "value" arguments are concatenated,
* separated by single blank characters, and the
* resulting string is assigned to the environment
* variable "name"
*
* If '-a key' is specified, the env block is encrypted with AES 128 CBC.
* The 'key' argument is in the format of 32 hexadecimal numbers (16 bytes
* of AES key), eg. '-a aabbccddeeff00112233445566778899'.
*/
#include <fcntl.h>
#include <getopt.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/file.h>
#include <unistd.h>
#include "fw_env.h"
#define CMD_PRINTENV "fw_printenv"
#define CMD_SETENV "fw_setenv"
static struct option long_options[] = {
{"script", required_argument, NULL, 's'},
{"help", no_argument, NULL, 'h'},
{NULL, 0, NULL, 0}
};
void usage(void)
{
fprintf(stderr, "fw_printenv/fw_setenv, "
"a command line interface to U-Boot environment\n\n"
#ifndef CONFIG_FILE
"usage:\tfw_printenv [-a key] [-n] [variable name]\n"
"\tfw_setenv [-a key] [variable name] [variable value]\n"
#else
"usage:\tfw_printenv [-c /my/fw_env.config] [-a key] [-n] [variable name]\n"
"\tfw_setenv [-c /my/fw_env.config] [-a key] [variable name] [variable value]\n"
#endif
"\tfw_setenv -s [ file ]\n"
"\tfw_setenv -s - < [ file ]\n\n"
"The file passed as argument contains only pairs "
"name / value\n"
"Example:\n"
"# Any line starting with # is treated as comment\n"
"\n"
"\t netdev eth0\n"
"\t kernel_addr 400000\n"
"\t var1\n"
"\t var2 The quick brown fox jumps over the "
"lazy dog\n"
"\n"
"A variable without value will be dropped. It is possible\n"
"to put any number of spaces between the fields, but any\n"
"space inside the value is treated as part of the value "
"itself.\n\n"
);
}
int main(int argc, char *argv[])
{
char *p;
char *cmdname = *argv;
char *script_file = NULL;
int c;
const char *lockname = "/var/lock/" CMD_PRINTENV ".lock";
int lockfd = -1;
int retval = EXIT_SUCCESS;
lockfd = open(lockname, O_WRONLY | O_CREAT | O_TRUNC, 0666);
if (-1 == lockfd) {
fprintf(stderr, "Error opening lock file %s\n", lockname);
return EXIT_FAILURE;
}
if (-1 == flock(lockfd, LOCK_EX)) {
fprintf(stderr, "Error locking file %s\n", lockname);
close(lockfd);
return EXIT_FAILURE;
}
if ((p = strrchr (cmdname, '/')) != NULL) {
cmdname = p + 1;
}
while ((c = getopt_long (argc, argv, "a:c:ns:h",
long_options, NULL)) != EOF) {
switch (c) {
case 'a':
/* AES key, handled later */
break;
case 'c':
/* handled later */
break;
case 'n':
/* handled in fw_printenv */
break;
case 's':
script_file = optarg;
break;
case 'h':
usage();
goto exit;
default: /* '?' */
fprintf(stderr, "Try `%s --help' for more information."
"\n", cmdname);
retval = EXIT_FAILURE;
goto exit;
}
}
if (strcmp(cmdname, CMD_PRINTENV) == 0) {
if (fw_printenv(argc, argv) != 0)
retval = EXIT_FAILURE;
} else if (strcmp(cmdname, CMD_SETENV) == 0) {
if (!script_file) {
if (fw_setenv(argc, argv) != 0)
retval = EXIT_FAILURE;
} else {
if (fw_parse_script(script_file) != 0)
retval = EXIT_FAILURE;
}
} else {
fprintf(stderr,
"Identity crisis - may be called as `" CMD_PRINTENV
"' or as `" CMD_SETENV "' but not as `%s'\n",
cmdname);
retval = EXIT_FAILURE;
}
exit:
flock(lockfd, LOCK_UN);
close(lockfd);
return retval;
}