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wdenkaffae2b2002-08-17 09:36:01 +00001/*
2 * (C) Copyright 2000
3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4 *
Wolfgang Denk1a459662013-07-08 09:37:19 +02005 * SPDX-License-Identifier: GPL-2.0+
wdenkaffae2b2002-08-17 09:36:01 +00006 */
7
8#include <common.h>
9#include <s_record.h>
10
11static int hex1_bin (char c);
12static int hex2_bin (char *s);
13
14int srec_decode (char *input, int *count, ulong *addr, char *data)
15{
16 int i;
17 int v; /* conversion buffer */
18 int srec_type; /* S-Record type */
19 unsigned char chksum; /* buffer for checksum */
20
21 chksum = 0;
22
23 /* skip anything before 'S', and the 'S' itself.
24 * Return error if not found
25 */
26
27 for (; *input; ++input) {
28 if (*input == 'S') { /* skip 'S' */
29 ++input;
30 break;
31 }
32 }
33 if (*input == '\0') { /* no more data? */
34 return (SREC_EMPTY);
35 }
36
37 v = *input++; /* record type */
38
39 if ((*count = hex2_bin(input)) < 0) {
40 return (SREC_E_NOSREC);
41 }
42
43 chksum += *count;
44 input += 2;
45
46 switch (v) { /* record type */
47
48 case '0': /* start record */
49 srec_type = SREC_START; /* 2 byte addr field */
50 *count -= 3; /* - checksum and addr */
51 break;
52 case '1':
53 srec_type = SREC_DATA2; /* 2 byte addr field */
54 *count -= 3; /* - checksum and addr */
55 break;
56 case '2':
57 srec_type = SREC_DATA3; /* 3 byte addr field */
58 *count -= 4; /* - checksum and addr */
59 break;
60 case '3': /* data record with a */
61 srec_type = SREC_DATA4; /* 4 byte addr field */
62 *count -= 5; /* - checksum and addr */
63 break;
64/*** case '4' ***/
65 case '5': /* count record, addr field contains */
66 srec_type = SREC_COUNT; /* a 2 byte record counter */
67 *count = 0; /* no data */
68 break;
69/*** case '6' -- not used ***/
70 case '7': /* end record with a */
71 srec_type = SREC_END4; /* 4 byte addr field */
72 *count -= 5; /* - checksum and addr */
73 break;
74 case '8': /* end record with a */
75 srec_type = SREC_END3; /* 3 byte addr field */
76 *count -= 4; /* - checksum and addr */
77 break;
78 case '9': /* end record with a */
79 srec_type = SREC_END2; /* 2 byte addr field */
80 *count -= 3; /* - checksum and addr */
81 break;
82 default:
83 return (SREC_E_BADTYPE);
84 }
85
86 /* read address field */
87 *addr = 0;
88
89 switch (v) {
90 case '3': /* 4 byte addr field */
91 case '7':
92 if ((v = hex2_bin(input)) < 0) {
93 return (SREC_E_NOSREC);
94 }
95 *addr += v;
96 chksum += v;
97 input += 2;
98 /* FALL THRU */
99 case '2': /* 3 byte addr field */
100 case '8':
101 if ((v = hex2_bin(input)) < 0) {
102 return (SREC_E_NOSREC);
103 }
104 *addr <<= 8;
105 *addr += v;
106 chksum += v;
107 input += 2;
108 /* FALL THRU */
109 case '0': /* 2 byte addr field */
110 case '1':
111 case '5':
112 case '9':
113 if ((v = hex2_bin(input)) < 0) {
114 return (SREC_E_NOSREC);
115 }
116 *addr <<= 8;
117 *addr += v;
118 chksum += v;
119 input += 2;
120
121 if ((v = hex2_bin(input)) < 0) {
122 return (SREC_E_NOSREC);
123 }
124 *addr <<= 8;
125 *addr += v;
126 chksum += v;
127 input += 2;
128
129 break;
130 default:
131 return (SREC_E_BADTYPE);
132 }
133
134 /* convert data and calculate checksum */
135 for (i=0; i < *count; ++i) {
136 if ((v = hex2_bin(input)) < 0) {
137 return (SREC_E_NOSREC);
138 }
139 data[i] = v;
140 chksum += v;
141 input += 2;
142 }
143
144 /* read anc check checksum */
145 if ((v = hex2_bin(input)) < 0) {
146 return (SREC_E_NOSREC);
147 }
148
149 if ((unsigned char)v != (unsigned char)~chksum) {
150 return (SREC_E_BADCHKS);
151 }
152
153 return (srec_type);
154}
155
156static int hex1_bin (char c)
157{
158 if (c >= '0' && c <= '9')
159 return (c - '0');
160 if (c >= 'a' && c <= 'f')
161 return (c + 10 - 'a');
162 if (c >= 'A' && c <= 'F')
163 return (c + 10 - 'A');
164 return (-1);
165}
166
167static int hex2_bin (char *s)
168{
169 int i, j;
170
171 if ((i = hex1_bin(*s++)) < 0) {
172 return (-1);
173 }
174 if ((j = hex1_bin(*s)) < 0) {
175 return (-1);
176 }
177
178 return ((i<<4) + j);
179}