Tom Rini | 10e4779 | 2018-05-06 17:58:06 -0400 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
wdenk | affae2b | 2002-08-17 09:36:01 +0000 | [diff] [blame] | 2 | /* |
| 3 | * (C) Copyright 2000 |
| 4 | * Wolfgang Denk, DENX Software Engineering, wd@denx.de. |
wdenk | affae2b | 2002-08-17 09:36:01 +0000 | [diff] [blame] | 5 | */ |
| 6 | |
wdenk | affae2b | 2002-08-17 09:36:01 +0000 | [diff] [blame] | 7 | #include <s_record.h> |
| 8 | |
| 9 | static int hex1_bin (char c); |
| 10 | static int hex2_bin (char *s); |
| 11 | |
| 12 | int srec_decode (char *input, int *count, ulong *addr, char *data) |
| 13 | { |
| 14 | int i; |
| 15 | int v; /* conversion buffer */ |
| 16 | int srec_type; /* S-Record type */ |
| 17 | unsigned char chksum; /* buffer for checksum */ |
| 18 | |
| 19 | chksum = 0; |
| 20 | |
| 21 | /* skip anything before 'S', and the 'S' itself. |
| 22 | * Return error if not found |
| 23 | */ |
| 24 | |
| 25 | for (; *input; ++input) { |
| 26 | if (*input == 'S') { /* skip 'S' */ |
| 27 | ++input; |
| 28 | break; |
| 29 | } |
| 30 | } |
| 31 | if (*input == '\0') { /* no more data? */ |
| 32 | return (SREC_EMPTY); |
| 33 | } |
| 34 | |
| 35 | v = *input++; /* record type */ |
| 36 | |
| 37 | if ((*count = hex2_bin(input)) < 0) { |
| 38 | return (SREC_E_NOSREC); |
| 39 | } |
| 40 | |
| 41 | chksum += *count; |
| 42 | input += 2; |
| 43 | |
| 44 | switch (v) { /* record type */ |
| 45 | |
| 46 | case '0': /* start record */ |
| 47 | srec_type = SREC_START; /* 2 byte addr field */ |
| 48 | *count -= 3; /* - checksum and addr */ |
| 49 | break; |
| 50 | case '1': |
| 51 | srec_type = SREC_DATA2; /* 2 byte addr field */ |
| 52 | *count -= 3; /* - checksum and addr */ |
| 53 | break; |
| 54 | case '2': |
| 55 | srec_type = SREC_DATA3; /* 3 byte addr field */ |
| 56 | *count -= 4; /* - checksum and addr */ |
| 57 | break; |
| 58 | case '3': /* data record with a */ |
| 59 | srec_type = SREC_DATA4; /* 4 byte addr field */ |
| 60 | *count -= 5; /* - checksum and addr */ |
| 61 | break; |
| 62 | /*** case '4' ***/ |
| 63 | case '5': /* count record, addr field contains */ |
| 64 | srec_type = SREC_COUNT; /* a 2 byte record counter */ |
| 65 | *count = 0; /* no data */ |
| 66 | break; |
| 67 | /*** case '6' -- not used ***/ |
| 68 | case '7': /* end record with a */ |
| 69 | srec_type = SREC_END4; /* 4 byte addr field */ |
| 70 | *count -= 5; /* - checksum and addr */ |
| 71 | break; |
| 72 | case '8': /* end record with a */ |
| 73 | srec_type = SREC_END3; /* 3 byte addr field */ |
| 74 | *count -= 4; /* - checksum and addr */ |
| 75 | break; |
| 76 | case '9': /* end record with a */ |
| 77 | srec_type = SREC_END2; /* 2 byte addr field */ |
| 78 | *count -= 3; /* - checksum and addr */ |
| 79 | break; |
| 80 | default: |
| 81 | return (SREC_E_BADTYPE); |
| 82 | } |
| 83 | |
| 84 | /* read address field */ |
| 85 | *addr = 0; |
| 86 | |
| 87 | switch (v) { |
| 88 | case '3': /* 4 byte addr field */ |
| 89 | case '7': |
| 90 | if ((v = hex2_bin(input)) < 0) { |
| 91 | return (SREC_E_NOSREC); |
| 92 | } |
| 93 | *addr += v; |
| 94 | chksum += v; |
| 95 | input += 2; |
| 96 | /* FALL THRU */ |
| 97 | case '2': /* 3 byte addr field */ |
| 98 | case '8': |
| 99 | if ((v = hex2_bin(input)) < 0) { |
| 100 | return (SREC_E_NOSREC); |
| 101 | } |
| 102 | *addr <<= 8; |
| 103 | *addr += v; |
| 104 | chksum += v; |
| 105 | input += 2; |
| 106 | /* FALL THRU */ |
| 107 | case '0': /* 2 byte addr field */ |
| 108 | case '1': |
| 109 | case '5': |
| 110 | case '9': |
| 111 | if ((v = hex2_bin(input)) < 0) { |
| 112 | return (SREC_E_NOSREC); |
| 113 | } |
| 114 | *addr <<= 8; |
| 115 | *addr += v; |
| 116 | chksum += v; |
| 117 | input += 2; |
| 118 | |
| 119 | if ((v = hex2_bin(input)) < 0) { |
| 120 | return (SREC_E_NOSREC); |
| 121 | } |
| 122 | *addr <<= 8; |
| 123 | *addr += v; |
| 124 | chksum += v; |
| 125 | input += 2; |
| 126 | |
| 127 | break; |
| 128 | default: |
| 129 | return (SREC_E_BADTYPE); |
| 130 | } |
| 131 | |
| 132 | /* convert data and calculate checksum */ |
| 133 | for (i=0; i < *count; ++i) { |
| 134 | if ((v = hex2_bin(input)) < 0) { |
| 135 | return (SREC_E_NOSREC); |
| 136 | } |
| 137 | data[i] = v; |
| 138 | chksum += v; |
| 139 | input += 2; |
| 140 | } |
| 141 | |
| 142 | /* read anc check checksum */ |
| 143 | if ((v = hex2_bin(input)) < 0) { |
| 144 | return (SREC_E_NOSREC); |
| 145 | } |
| 146 | |
| 147 | if ((unsigned char)v != (unsigned char)~chksum) { |
| 148 | return (SREC_E_BADCHKS); |
| 149 | } |
| 150 | |
| 151 | return (srec_type); |
| 152 | } |
| 153 | |
| 154 | static int hex1_bin (char c) |
| 155 | { |
| 156 | if (c >= '0' && c <= '9') |
| 157 | return (c - '0'); |
| 158 | if (c >= 'a' && c <= 'f') |
| 159 | return (c + 10 - 'a'); |
| 160 | if (c >= 'A' && c <= 'F') |
| 161 | return (c + 10 - 'A'); |
| 162 | return (-1); |
| 163 | } |
| 164 | |
| 165 | static int hex2_bin (char *s) |
| 166 | { |
| 167 | int i, j; |
| 168 | |
| 169 | if ((i = hex1_bin(*s++)) < 0) { |
| 170 | return (-1); |
| 171 | } |
| 172 | if ((j = hex1_bin(*s)) < 0) { |
| 173 | return (-1); |
| 174 | } |
| 175 | |
| 176 | return ((i<<4) + j); |
| 177 | } |