cmd/binop.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2
   3 #include <common.h>
   4 #include <command.h>
   5 #include <malloc.h>
   6 #include <mapmem.h>
   7 #include <linux/ctype.h>
   8
   9 enum {
  10         OP_ID_XOR,
  11         OP_ID_AND,
  12         OP_ID_OR,
  13 };
  14
  15 void write_to_env_var(char *varname, u8 *result, ulong len)
  16 {
  17         char *str_output;
  18         char *str_ptr;
  19         int i;
  20
  21         str_output = malloc(len * 2 + 1);
  22         str_ptr = str_output;
  23
  24         for (i = 0; i < len; i++) {
  25                 sprintf(str_ptr, "%02x", result[i]);
  26                 str_ptr += 2;
  27         }
  28         *str_ptr = '\0';
  29         setenv(varname, str_output);
  30
  31         free(str_output);
  32 }
  33
  34 void decode_hexstring(char *hexstr, u8 *result)
  35 {
  36         int i;
  37         int acc = 0;
  38
  39         for (i = 0; i < strlen(hexstr); ++i) {
  40                 char d = hexstr[i];
  41                 int value;
  42
  43                 if (isdigit(d))
  44                         value = (d - '0');
  45                 else
  46                         value = (islower(d) ? toupper(d) : d) - 'A' + 10;
  47
  48                 if (i % 2 == 0) {
  49                         acc = value * 16;
  50                 } else {
  51                         result[i / 2] = acc + value;
  52                         acc = 0;
  53                 }
  54         }
  55 }
  56
  57 void read_from_env_var(char *varname, u8 *result)
  58 {
  59         char *str_value;
  60
  61         str_value = getenv(varname);
  62         if (str_value)
  63                 decode_hexstring(str_value, result);
  64         else
  65                 decode_hexstring(varname, result);
  66 }
  67
  68 void read_from_mem(ulong addr, u8 *result, ulong len)
  69 {
  70         u8 *src;
  71
  72         src = map_sysmem(addr, len);
  73         memcpy(result, src, len);
  74         unmap_sysmem(src);
  75 }
  76
  77 void write_to_mem(char *varname, u8 *result, ulong len)
  78 {
  79         ulong addr;
  80         u8 *buf;
  81
  82         addr = simple_strtoul(varname, NULL, 16);
  83         buf = map_sysmem(addr, len);
  84         memcpy(buf, result, len);
  85         unmap_sysmem(buf);
  86 }
  87
  88 static int do_binop(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
  89 {
  90         ulong len;
  91         u8 *result, *src1, *src2;
  92         char *oparg, *lenarg, *src1arg, *src2arg, *destarg;
  93         int i, op;
  94
  95         if (argc < 5)
  96                 return CMD_RET_USAGE;
  97
  98         oparg = argv[1];
  99         lenarg = argv[2];
 100         src1arg = argv[3];
 101         src2arg = argv[4];
 102
 103         if (!strcmp(oparg, "xor"))
 104                 op = OP_ID_XOR;
 105         else if (!strcmp(oparg, "or"))
 106                 op = OP_ID_OR;
 107         else if (!strcmp(oparg, "and"))
 108                 op = OP_ID_AND;
 109         else
 110                 return CMD_RET_USAGE;
 111
 112         len = simple_strtoul(lenarg, NULL, 10);
 113
 114         src1 = malloc(len);
 115         src2 = malloc(len);
 116
 117         if (*src1arg == '*')
 118                 read_from_mem(simple_strtoul(src1arg + 1, NULL, 16), src1, len);
 119         else
 120                 read_from_env_var(src1arg, src1);
 121
 122         if (*src2arg == '*')
 123                 read_from_mem(simple_strtoul(src2arg + 1, NULL, 16), src2, len);
 124         else
 125                 read_from_env_var(src2arg, src2);
 126
 127         result = malloc(len);
 128
 129         switch (op) {
 130         case OP_ID_XOR:
 131                 for (i = 0; i < len; i++)
 132                         result[i] = src1[i] ^ src2[i];
 133                 break;
 134         case OP_ID_OR:
 135                 for (i = 0; i < len; i++)
 136                         result[i] = src1[i] | src2[i];
 137                 break;
 138         case OP_ID_AND:
 139                 for (i = 0; i < len; i++)
 140                         result[i] = src1[i] & src2[i];
 141                 break;
 142         }
 143
 144         if (argc == 5) {
 145                 for (i = 0; i < len; i++) {
 146                         printf("%02x ", result[i]);
 147                         if (i % 16 == 15)
 148                                 puts("\n");
 149                 }
 150                 puts("\n");
 151
 152                 goto exit;
 153         }
 154
 155         destarg = argv[5];
 156
 157         if (*destarg == '*')
 158                 write_to_mem(destarg + 1, result, len); /* Skip asterisk */
 159         else
 160                 write_to_env_var(destarg, result, len);
 161 exit:
 162         free(result);
 163         free(src2);
 164         free(src1);
 165
 166         return 0;
 167 }
 168
 169 U_BOOT_CMD(
 170         binop,  6,      1,      do_binop,
 171         "compute binary operation",
 172         "op count [*]src1 [*]src2 [[*]dest]\n"
 173                 "    - compute binary operation of data at/in src1 and\n      src2 (either *memaddr, env var name or hex string)\n      and store result in/at dest, where op is one of\n      xor, or, and."
 174 );