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/*
* Copyright 2008 Freescale Semiconductor, Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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
*/
/*
* This file provides a shell like 'expr' function to return.
*/
#include <common.h>
#include <config.h>
#include <command.h>
static ulong get_arg(char *s, int w)
{
ulong *p;
/*
* if the parameter starts with a '*' then assume
* it is a pointer to the value we want
*/
if (s[0] == '*') {
p = (ulong *)simple_strtoul(&s[1], NULL, 16);
switch (w) {
case 1: return((ulong)(*(uchar *)p));
case 2: return((ulong)(*(ushort *)p));
case 4:
default: return(*p);
}
} else {
return simple_strtoul(s, NULL, 16);
}
}
static int do_setexpr(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
ulong a, b;
ulong value;
int w;
if (argc < 3)
return CMD_RET_USAGE;
w = cmd_get_data_size(argv[0], 4);
a = get_arg(argv[2], w);
/* plain assignment: "setexpr name value" */
if (argc == 3) {
setenv_hex(argv[1], a);
return 0;
}
/* standard operators: "setexpr name val1 op val2" */
if (argc != 5)
return CMD_RET_USAGE;
if (strlen(argv[3]) != 1)
return CMD_RET_USAGE;
b = get_arg(argv[4], w);
switch (argv[3][0]) {
case '|':
value = a | b;
break;
case '&':
value = a & b;
break;
case '+':
value = a + b;
break;
case '^':
value = a ^ b;
break;
case '-':
value = a - b;
break;
case '*':
value = a * b;
break;
case '/':
value = a / b;
break;
case '%':
value = a % b;
break;
default:
printf("invalid op\n");
return 1;
}
setenv_hex(argv[1], value);
return 0;
}
U_BOOT_CMD(
setexpr, 5, 0, do_setexpr,
"set environment variable as the result of eval expression",
"[.b, .w, .l] name [*]value1 <op> [*]value2\n"
" - set environment variable 'name' to the result of the evaluated\n"
" express specified by <op>. <op> can be &, |, ^, +, -, *, /, %\n"
" size argument is only meaningful if value1 and/or value2 are\n"
" memory addresses (*)\n"
"setexpr[.b, .w, .l] name [*]value\n"
" - load a value into a variable"
);
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