common/s_record.c

   1 /*
   2  * (C) Copyright 2000
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  */
  23
  24 #include <common.h>
  25 #include <s_record.h>
  26
  27 static int hex1_bin (char  c);
  28 static int hex2_bin (char *s);
  29
  30 int srec_decode (char *input, int *count, ulong *addr, char *data)
  31 {
  32         int     i;
  33         int     v;                              /* conversion buffer    */
  34         int     srec_type;                      /* S-Record type        */
  35         unsigned char chksum;                   /* buffer for checksum  */
  36
  37         chksum = 0;
  38
  39         /* skip anything before 'S', and the 'S' itself.
  40          * Return error if not found
  41          */
  42
  43         for (; *input; ++input) {
  44                 if (*input == 'S') {            /* skip 'S' */
  45                         ++input;
  46                         break;
  47                 }
  48         }
  49         if (*input == '\0') {                   /* no more data?        */
  50                 return (SREC_EMPTY);
  51         }
  52
  53         v = *input++;                           /* record type          */
  54
  55         if ((*count = hex2_bin(input)) < 0) {
  56                 return (SREC_E_NOSREC);
  57         }
  58
  59         chksum += *count;
  60         input  += 2;
  61
  62         switch (v) {                            /* record type          */
  63
  64         case '0':                               /* start record         */
  65                 srec_type = SREC_START;         /* 2 byte addr field    */
  66                 *count   -= 3;                  /* - checksum and addr  */
  67                 break;
  68         case '1':
  69                 srec_type = SREC_DATA2;         /* 2 byte addr field    */
  70                 *count   -= 3;                  /* - checksum and addr  */
  71                 break;
  72         case '2':
  73                 srec_type = SREC_DATA3;         /* 3 byte addr field    */
  74                 *count   -= 4;                  /* - checksum and addr  */
  75                 break;
  76         case '3':                               /* data record with a   */
  77                 srec_type = SREC_DATA4;         /* 4 byte addr field    */
  78                 *count   -= 5;                  /* - checksum and addr  */
  79                 break;
  80 /***    case '4'  ***/
  81         case '5':                       /* count record, addr field contains */
  82                 srec_type = SREC_COUNT; /* a 2 byte record counter      */
  83                 *count    = 0;                  /* no data              */
  84                 break;
  85 /***    case '6' -- not used  ***/
  86         case '7':                               /* end record with a    */
  87                 srec_type = SREC_END4;          /* 4 byte addr field    */
  88                 *count   -= 5;                  /* - checksum and addr  */
  89                 break;
  90         case '8':                               /* end record with a    */
  91                 srec_type = SREC_END3;          /* 3 byte addr field    */
  92                 *count   -= 4;                  /* - checksum and addr  */
  93                 break;
  94         case '9':                               /* end record with a    */
  95                 srec_type = SREC_END2;          /* 2 byte addr field    */
  96                 *count   -= 3;                  /* - checksum and addr  */
  97                 break;
  98         default:
  99                 return (SREC_E_BADTYPE);
 100         }
 101
 102         /* read address field */
 103         *addr = 0;
 104
 105         switch (v) {
 106         case '3':                               /* 4 byte addr field    */
 107         case '7':
 108                 if ((v = hex2_bin(input)) < 0) {
 109                         return (SREC_E_NOSREC);
 110                 }
 111                 *addr  += v;
 112                 chksum += v;
 113                 input  += 2;
 114                 /* FALL THRU */
 115         case '2':                               /* 3 byte addr field    */
 116         case '8':
 117                 if ((v = hex2_bin(input)) < 0) {
 118                         return (SREC_E_NOSREC);
 119                 }
 120                 *addr <<= 8;
 121                 *addr  += v;
 122                 chksum += v;
 123                 input  += 2;
 124                 /* FALL THRU */
 125         case '0':                               /* 2 byte addr field    */
 126         case '1':
 127         case '5':
 128         case '9':
 129                 if ((v = hex2_bin(input)) < 0) {
 130                         return (SREC_E_NOSREC);
 131                 }
 132                 *addr <<= 8;
 133                 *addr  += v;
 134                 chksum += v;
 135                 input  += 2;
 136
 137                 if ((v = hex2_bin(input)) < 0) {
 138                         return (SREC_E_NOSREC);
 139                 }
 140                 *addr <<= 8;
 141                 *addr  += v;
 142                 chksum += v;
 143                 input  += 2;
 144
 145                 break;
 146         default:
 147                 return (SREC_E_BADTYPE);
 148         }
 149
 150         /* convert data and calculate checksum */
 151         for (i=0; i < *count; ++i) {
 152                 if ((v = hex2_bin(input)) < 0) {
 153                         return (SREC_E_NOSREC);
 154                 }
 155                 data[i] = v;
 156                 chksum += v;
 157                 input  += 2;
 158         }
 159
 160         /* read anc check checksum */
 161         if ((v = hex2_bin(input)) < 0) {
 162                 return (SREC_E_NOSREC);
 163         }
 164
 165         if ((unsigned char)v != (unsigned char)~chksum) {
 166                 return (SREC_E_BADCHKS);
 167         }
 168
 169         return (srec_type);
 170 }
 171
 172 static int hex1_bin (char c)
 173 {
 174         if (c >= '0' && c <= '9')
 175                 return (c - '0');
 176         if (c >= 'a' && c <= 'f')
 177                 return (c + 10 - 'a');
 178         if (c >= 'A' && c <= 'F')
 179                 return (c + 10 - 'A');
 180         return (-1);
 181 }
 182
 183 static int hex2_bin (char *s)
 184 {
 185         int i, j;
 186
 187         if ((i = hex1_bin(*s++)) < 0) {
 188                 return (-1);
 189         }
 190         if ((j = hex1_bin(*s)) < 0) {
 191                 return (-1);
 192         }
 193
 194         return ((i<<4) + j);
 195 }