s_record.c
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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2000
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*/
#include <common.h>
#include <s_record.h>
static int hex1_bin (char c);
static int hex2_bin (char *s);
int srec_decode (char *input, int *count, ulong *addr, char *data)
{
int i;
int v; /* conversion buffer */
int srec_type; /* S-Record type */
unsigned char chksum; /* buffer for checksum */
chksum = 0;
/* skip anything before 'S', and the 'S' itself.
* Return error if not found
*/
for (; *input; ++input) {
if (*input == 'S') { /* skip 'S' */
++input;
break;
}
}
if (*input == '\0') { /* no more data? */
return (SREC_EMPTY);
}
v = *input++; /* record type */
if ((*count = hex2_bin(input)) < 0) {
return (SREC_E_NOSREC);
}
chksum += *count;
input += 2;
switch (v) { /* record type */
case '0': /* start record */
srec_type = SREC_START; /* 2 byte addr field */
*count -= 3; /* - checksum and addr */
break;
case '1':
srec_type = SREC_DATA2; /* 2 byte addr field */
*count -= 3; /* - checksum and addr */
break;
case '2':
srec_type = SREC_DATA3; /* 3 byte addr field */
*count -= 4; /* - checksum and addr */
break;
case '3': /* data record with a */
srec_type = SREC_DATA4; /* 4 byte addr field */
*count -= 5; /* - checksum and addr */
break;
/*** case '4' ***/
case '5': /* count record, addr field contains */
srec_type = SREC_COUNT; /* a 2 byte record counter */
*count = 0; /* no data */
break;
/*** case '6' -- not used ***/
case '7': /* end record with a */
srec_type = SREC_END4; /* 4 byte addr field */
*count -= 5; /* - checksum and addr */
break;
case '8': /* end record with a */
srec_type = SREC_END3; /* 3 byte addr field */
*count -= 4; /* - checksum and addr */
break;
case '9': /* end record with a */
srec_type = SREC_END2; /* 2 byte addr field */
*count -= 3; /* - checksum and addr */
break;
default:
return (SREC_E_BADTYPE);
}
/* read address field */
*addr = 0;
switch (v) {
case '3': /* 4 byte addr field */
case '7':
if ((v = hex2_bin(input)) < 0) {
return (SREC_E_NOSREC);
}
*addr += v;
chksum += v;
input += 2;
/* FALL THRU */
case '2': /* 3 byte addr field */
case '8':
if ((v = hex2_bin(input)) < 0) {
return (SREC_E_NOSREC);
}
*addr <<= 8;
*addr += v;
chksum += v;
input += 2;
/* FALL THRU */
case '0': /* 2 byte addr field */
case '1':
case '5':
case '9':
if ((v = hex2_bin(input)) < 0) {
return (SREC_E_NOSREC);
}
*addr <<= 8;
*addr += v;
chksum += v;
input += 2;
if ((v = hex2_bin(input)) < 0) {
return (SREC_E_NOSREC);
}
*addr <<= 8;
*addr += v;
chksum += v;
input += 2;
break;
default:
return (SREC_E_BADTYPE);
}
/* convert data and calculate checksum */
for (i=0; i < *count; ++i) {
if ((v = hex2_bin(input)) < 0) {
return (SREC_E_NOSREC);
}
data[i] = v;
chksum += v;
input += 2;
}
/* read anc check checksum */
if ((v = hex2_bin(input)) < 0) {
return (SREC_E_NOSREC);
}
if ((unsigned char)v != (unsigned char)~chksum) {
return (SREC_E_BADCHKS);
}
return (srec_type);
}
static int hex1_bin (char c)
{
if (c >= '0' && c <= '9')
return (c - '0');
if (c >= 'a' && c <= 'f')
return (c + 10 - 'a');
if (c >= 'A' && c <= 'F')
return (c + 10 - 'A');
return (-1);
}
static int hex2_bin (char *s)
{
int i, j;
if ((i = hex1_bin(*s++)) < 0) {
return (-1);
}
if ((j = hex1_bin(*s)) < 0) {
return (-1);
}
return ((i<<4) + j);
}