blob: c52bf1bb65b8e63768614abef1b3668d2c257962 [file] [log] [blame]
wdenkaffae2b2002-08-17 09:36:01 +00001/*
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
27static int hex1_bin (char c);
28static int hex2_bin (char *s);
29
30int 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
172static 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
183static 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}