1 /*
2 * Copyright 2008 Freescale Semiconductor, Inc.
3 *
4 * See file CREDITS for list of people who contributed to this
5 * project.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of
10 * the License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
20 * MA 02111-1307 USA
21 */
23 /*
24 * This file provides a shell like 'expr' function to return.
25 */
27 #include <common.h>
28 #include <config.h>
29 #include <command.h>
31 static ulong get_arg(char *s, int w)
32 {
33 ulong *p;
35 /*
36 * if the parameter starts with a '*' then assume
37 * it is a pointer to the value we want
38 */
40 if (s[0] == '*') {
41 p = (ulong *)simple_strtoul(&s[1], NULL, 16);
42 switch (w) {
43 case 1: return((ulong)(*(uchar *)p));
44 case 2: return((ulong)(*(ushort *)p));
45 case 4:
46 default: return(*p);
47 }
48 } else {
49 return simple_strtoul(s, NULL, 16);
50 }
51 }
53 static int do_setexpr(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
54 {
55 ulong a, b;
56 char buf[16];
57 int w;
59 /* Validate arguments */
60 if (argc != 5 && argc != 3)
61 return CMD_RET_USAGE;
62 if (argc == 5 && strlen(argv[3]) != 1)
63 return CMD_RET_USAGE;
65 w = cmd_get_data_size(argv[0], 4);
67 a = get_arg(argv[2], w);
69 if (argc == 3) {
70 sprintf(buf, "%lx", a);
71 setenv(argv[1], buf);
73 return 0;
74 }
76 b = get_arg(argv[4], w);
78 switch (argv[3][0]) {
79 case '|': sprintf(buf, "%lx", (a | b)); break;
80 case '&': sprintf(buf, "%lx", (a & b)); break;
81 case '+': sprintf(buf, "%lx", (a + b)); break;
82 case '^': sprintf(buf, "%lx", (a ^ b)); break;
83 case '-': sprintf(buf, "%lx", (a - b)); break;
84 case '*': sprintf(buf, "%lx", (a * b)); break;
85 case '/': sprintf(buf, "%lx", (a / b)); break;
86 case '%': sprintf(buf, "%lx", (a % b)); break;
87 default:
88 printf("invalid op\n");
89 return 1;
90 }
92 setenv(argv[1], buf);
94 return 0;
95 }
97 U_BOOT_CMD(
98 setexpr, 5, 0, do_setexpr,
99 "set environment variable as the result of eval expression",
100 "[.b, .w, .l] name [*]value1 <op> [*]value2\n"
101 " - set environment variable 'name' to the result of the evaluated\n"
102 " express specified by <op>. <op> can be &, |, ^, +, -, *, /, %\n"
103 " size argument is only meaningful if value1 and/or value2 are\n"
104 " memory addresses (*)\n"
105 "setexpr[.b, .w, .l] name *value\n"
106 " - load a memory address into a variable"
107 );