--- a/loadtools/srecreader.c	Tue Apr 30 07:19:48 2013 +0000
+++ b/loadtools/srecreader.c	Tue Apr 30 21:35:14 2013 +0000
@@ -3,6 +3,7 @@
  */
 
 #include <sys/types.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <ctype.h>
 #include <strings.h>
@@ -20,9 +21,70 @@
 	return(0);
 }
 
+static
+srec2bin(sr, asciiline)
+	struct srecreader *sr;
+	char *asciiline;
+{
+	register int i, l, b;
+
+	l = decode_hex_byte(asciiline + 2);
+	if (l < 1) {
+		fprintf(stderr, "%s line %d: S-record length octet is bad\n",
+			sr->filename, sr->lineno);
+		return(-1);
+	}
+	sr->record[0] = l;
+	for (i = 1; i <= l; i++) {
+		b = decode_hex_byte(asciiline + i*2 + 2);
+		if (b < 0) {
+			fprintf(stderr,
+				"%s line %d: S-record hex decode error\n",
+				sr->filename, sr->lineno);
+			return(-1);
+		}
+		sr->record[i] = b;
+	}
+	return(0);
+}
+
+static
+srec_cksum(sr)
+	struct srecreader *sr;
+{
+	u_char accum;
+	register int i, len;
+
+	len = sr->record[0] + 1;
+	accum = 0;
+	for (i = 0; i < len; i++)
+		accum += sr->record[i];
+	if (accum != 0xFF) {
+		fprintf(stderr, "%s line %d: bad S-record checksum\n",
+			sr->filename, sr->lineno);
+		return(-1);
+	}
+	return(0);
+}
+
 read_s_record(sr)
 	struct srecreader *sr;
 {
-
+	char asciiline[1024];
 
+	if (!fgets(asciiline, sizeof asciiline, sr->openfile)) {
+		fprintf(stderr, "%s: premature EOF after %d S-records\n",
+			sr->filename, sr->lineno);
+		return(-1);
+	}
+	sr->lineno++;
+	if (asciiline[0] != 'S' || !isdigit(asciiline[1])) {
+		fprintf(stderr, "%s line %d: S-record expected\n",
+			sr->filename, sr->lineno);
+		return(-1);
+	}
+	sr->record_type = asciiline[1];
+	if (srec2bin(sr, asciiline) < 0)
+		return(-1);
+	return srec_cksum(sr);
 }