common/cmd_itest.c

   1 /*
   2  * (C) Copyright 2003
   3  * Tait Electronics Limited, Christchurch, New Zealand
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 /*
   9  * This file provides a shell like 'test' function to return
  10  * true/false from an integer or string compare of two memory
  11  * locations or a location and a scalar/literal.
  12  * A few parts were lifted from bash 'test' command
  13  */
  14
  15 #include <common.h>
  16 #include <config.h>
  17 #include <command.h>
  18
  19 #define EQ      0
  20 #define NE      1
  21 #define LT      2
  22 #define GT      3
  23 #define LE      4
  24 #define GE      5
  25
  26 struct op_tbl_s {
  27         char    *op;            /* operator string */
  28         int     opcode;         /* internal representation of opcode */
  29 };
  30
  31 typedef struct op_tbl_s op_tbl_t;
  32
  33 static const op_tbl_t op_table [] = {
  34         { "-lt", LT },
  35         { "<"  , LT },
  36         { "-gt", GT },
  37         { ">"  , GT },
  38         { "-eq", EQ },
  39         { "==" , EQ },
  40         { "-ne", NE },
  41         { "!=" , NE },
  42         { "<>" , NE },
  43         { "-ge", GE },
  44         { ">=" , GE },
  45         { "-le", LE },
  46         { "<=" , LE },
  47 };
  48
  49 static long evalexp(char *s, int w)
  50 {
  51         long l = 0;
  52         long *p;
  53
  54         /* if the parameter starts with a * then assume is a pointer to the value we want */
  55         if (s[0] == '*') {
  56                 p = (long *)simple_strtoul(&s[1], NULL, 16);
  57                 switch (w) {
  58                 case 1: return((long)(*(unsigned char *)p));
  59                 case 2: return((long)(*(unsigned short *)p));
  60                 case 4: return(*p);
  61                 }
  62         } else {
  63                 l = simple_strtoul(s, NULL, 16);
  64         }
  65
  66         return l & ((1UL << (w * 8)) - 1);
  67 }
  68
  69 static char * evalstr(char *s)
  70 {
  71         /* if the parameter starts with a * then assume a string pointer else its a literal */
  72         if (s[0] == '*') {
  73                 return (char *)simple_strtoul(&s[1], NULL, 16);
  74         } else if (s[0] == '$') {
  75                 int i = 2;
  76
  77                 if (s[1] != '{')
  78                         return NULL;
  79
  80                 while (s[i] != '}') {
  81                         if (s[i] == 0)
  82                                 return NULL;
  83                         i++;
  84                 }
  85                 s[i] = 0;
  86                 return  getenv((const char *)&s[2]);
  87         } else {
  88                 return s;
  89         }
  90 }
  91
  92 static int stringcomp(char *s, char *t, int op)
  93 {
  94         int p;
  95         char *l, *r;
  96
  97         l = evalstr(s);
  98         r = evalstr(t);
  99
 100         p = strcmp(l, r);
 101         switch (op) {
 102         case EQ: return (p == 0);
 103         case NE: return (p != 0);
 104         case LT: return (p < 0);
 105         case GT: return (p > 0);
 106         case LE: return (p <= 0);
 107         case GE: return (p >= 0);
 108         }
 109         return (0);
 110 }
 111
 112 static int arithcomp (char *s, char *t, int op, int w)
 113 {
 114         long l, r;
 115
 116         l = evalexp (s, w);
 117         r = evalexp (t, w);
 118
 119         switch (op) {
 120         case EQ: return (l == r);
 121         case NE: return (l != r);
 122         case LT: return (l < r);
 123         case GT: return (l > r);
 124         case LE: return (l <= r);
 125         case GE: return (l >= r);
 126         }
 127         return (0);
 128 }
 129
 130 static int binary_test(char *op, char *arg1, char *arg2, int w)
 131 {
 132         int len, i;
 133         const op_tbl_t *optp;
 134
 135         len = strlen(op);
 136
 137         for (optp = (op_tbl_t *)&op_table, i = 0;
 138              i < ARRAY_SIZE(op_table);
 139              optp++, i++) {
 140
 141                 if ((strncmp (op, optp->op, len) == 0) && (len == strlen (optp->op))) {
 142                         if (w == 0) {
 143                                 return (stringcomp(arg1, arg2, optp->opcode));
 144                         } else {
 145                                 return (arithcomp (arg1, arg2, optp->opcode, w));
 146                         }
 147                 }
 148         }
 149
 150         printf("Unknown operator '%s'\n", op);
 151         return 0;       /* op code not found */
 152 }
 153
 154 /* command line interface to the shell test */
 155 static int do_itest(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 156 {
 157         int     value, w;
 158
 159         /* Validate arguments */
 160         if ((argc != 4))
 161                 return CMD_RET_USAGE;
 162
 163         /* Check for a data width specification.
 164          * Defaults to long (4) if no specification.
 165          * Uses -2 as 'width' for .s (string) so as not to upset existing code
 166          */
 167         switch (w = cmd_get_data_size(argv[0], 4)) {
 168         case 1:
 169         case 2:
 170         case 4:
 171                 value = binary_test (argv[2], argv[1], argv[3], w);
 172                 break;
 173         case -2:
 174                 value = binary_test (argv[2], argv[1], argv[3], 0);
 175                 break;
 176         case -1:
 177         default:
 178                 puts("Invalid data width specifier\n");
 179                 value = 0;
 180                 break;
 181         }
 182
 183         return !value;
 184 }
 185
 186 U_BOOT_CMD(
 187         itest, 4, 0, do_itest,
 188         "return true/false on integer compare",
 189         "[.b, .w, .l, .s] [*]value1 <op> [*]value2"
 190 );