source: SVN/rincon/u-boot/common/cmd_itest.c @ 55

/*
 * (C) Copyright 2003
 * Tait Electronics Limited, Christchurch, New Zealand
 *
 * 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 'test' function to return
 * true/false from an integer or string compare of two memory
 * locations or a location and a scalar/literal.
 * A few parts were lifted from bash 'test' command
 */

#include <common.h>
#include <config.h>
#include <command.h>

#define EQ      0
#define NE      1
#define LT      2
#define GT      3
#define LE      4
#define GE      5

struct op_tbl_s {
        char    *op;            /* operator string */
        int     opcode;         /* internal representation of opcode */
};

typedef struct op_tbl_s op_tbl_t;

op_tbl_t op_table [] = {
        { "-lt", LT },
        { "<"  , LT },
        { "-gt", GT },
        { ">"  , GT },
        { "-eq", EQ },
        { "==" , EQ },
        { "-ne", NE },
        { "!=" , NE },
        { "<>" , NE },
        { "-ge", GE },
        { ">=" , GE },
        { "-le", LE },
        { "<=" , LE },
};

#define op_tbl_size (sizeof(op_table)/sizeof(op_table[0]))

static long evalexp(char *s, int w)
{
        long l, *p;

        /* if the parameter starts with a * then assume is a pointer to the value we want */
        if (s[0] == '*') {
                p = (long *)simple_strtoul(&s[1], NULL, 16);
                l = *p;
        } else {
                l = simple_strtoul(s, NULL, 16);
        }

        return (l & ((1 << (w * 8)) - 1));
}

static char * evalstr(char *s)
{
        /* if the parameter starts with a * then assume a string pointer else its a literal */
        if (s[0] == '*') {
                return (char *)simple_strtoul(&s[1], NULL, 16);
        } else {
                return s;
        }
}

static int stringcomp(char *s, char *t, int op)
{
        int n, p;
        char *l, *r;

        l = evalstr(s);
        r = evalstr(t);

        /* we'll do a compare based on the length of the shortest string */
        n = min(strlen(l), strlen(r));

        p = strncmp(l, r, n);
        switch (op) {
        case EQ: return (p == 0);
        case NE: return (p != 0);
        case LT: return (p < 0);
        case GT: return (p > 0);
        case LE: return (p <= 0);
        case GE: return (p >= 0);
        }
        return (0);
}

static int arithcomp (char *s, char *t, int op, int w)
{
        long l, r;

        l = evalexp (s, w);
        r = evalexp (t, w);

        switch (op) {
        case EQ: return (l == r);
        case NE: return (l != r);
        case LT: return (l < r);
        case GT: return (l > r);
        case LE: return (l <= r);
        case GE: return (l >= r);
        }
        return (0);
}

int binary_test (char *op, char *arg1, char *arg2, int w)
{
        int len, i;
        op_tbl_t *optp;

        len = strlen(op);

        for (optp = (op_tbl_t *)&op_table, i = 0;
             i < op_tbl_size;
             optp++, i++) {

                if ((strncmp (op, optp->op, len) == 0) && (len == strlen (optp->op))) {
                        if (w == 0) {
                                return (stringcomp(arg1, arg2, optp->opcode));
                        } else {
                                return (arithcomp (arg1, arg2, optp->opcode, w));
                        }
                }
        }

        printf("Unknown operator '%s'\n", op);
        return 0;       /* op code not found */
}

/* command line interface to the shell test */
int do_itest ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[] )
{
        int     value, w;

        /* Validate arguments */
        if ((argc != 4)){
                printf("Usage:\n%s\n", cmdtp->usage);
                return 1;
        }

        /* Check for a data width specification.
         * Defaults to long (4) if no specification.
         * Uses -2 as 'width' for .s (string) so as not to upset existing code
         */
        switch (w = cmd_get_data_size(argv[0], 4)) {
        case 1:
        case 2:
        case 4:
                value = binary_test (argv[2], argv[1], argv[3], w);
                break;
        case -2:
                value = binary_test (argv[2], argv[1], argv[3], 0);
                break;
        case -1:
        default:
                puts("Invalid data width specifier\n");
                value = 0;
                break;
        }

        return !value;
}

U_BOOT_CMD(
        itest, 4, 0, do_itest,
        "itest\t- return true/false on integer compare\n",
        "[.b, .w, .l, .s] [*]value1 <op> [*]value2\n"
);