From 06f04fb66784a047c534c58d01f7c0c7ba70cab5 Mon Sep 17 00:00:00 2001
From: Leo C <erbl259-lmu@yahoo.de>
Date: Mon, 17 Jun 2019 23:12:03 +0200
Subject: [PATCH] New utility prl2offz: Make .com from .prl and convert prl
 reloc bitmap to compressed list of offsets

---
 .gitignore |   1 +
 prl2offz.c | 208 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 209 insertions(+)
 create mode 100644 prl2offz.c

diff --git a/.gitignore b/.gitignore
index a6a06c2..8d65030 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,3 +9,4 @@ autorevision.cache
 version.inc
 config.inc
 ddt180.180
+prl2offz
diff --git a/prl2offz.c b/prl2offz.c
new file mode 100644
index 0000000..7e0a6bf
--- /dev/null
+++ b/prl2offz.c
@@ -0,0 +1,208 @@
+/*
+ * (C) Copyright 2019 Leo C. <erbl259-lmu@yahoo.de>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <string.h>
+
+char *progname;
+FILE *prlfile;
+char *prlfilename;
+FILE *outfile;
+char *outfilename;
+uint16_t progsize;
+
+void die(int status, const char *format, ...)
+{
+	va_list arg;
+
+	fflush(stdout);
+	va_start(arg, format);
+	fprintf(stderr, "%s: ", progname);
+	vfprintf(stderr, format, arg);
+	va_end(arg);
+
+	exit(status);
+}
+
+static
+int get_bit(void)
+{
+	static unsigned bitpos;
+	static int bytebuf;
+	int retval;
+
+	if (bitpos == progsize) {
+		return -2;
+	}
+	if (bitpos%8 == 0) {
+		bytebuf = fgetc(prlfile);
+		if (bytebuf == EOF) {
+			return -1;
+		}
+	}
+	retval = (bytebuf & 0x80) !=0;
+	bytebuf <<= 1;
+	bitpos++;
+
+	return retval;
+}
+
+static
+int get_nr_of_bits(void)
+{
+	int bits = 0;
+	int bit;
+
+	do {
+		bits++;
+	} while ((bit = get_bit()) == 0);
+
+	if (bit >= 0)
+		return bits;
+
+	if (bit == -2)
+		return 0;
+
+	return bit;
+}
+
+static
+void put_bits(int width, unsigned val)
+{
+	static unsigned bytebuf;
+	static int bitcount = 8;
+
+	while (width--) {
+		bytebuf <<= 1;
+		if (val & (1 << width))
+			bytebuf += 1;
+		bitcount--;
+		if (bitcount == 0) {
+			if (fputc(bytebuf, outfile) == EOF)
+				die(1,"Error writing output file %s: %s\n",
+						outfilename, strerror(errno));
+			bitcount = 8;
+		}
+	}
+}
+
+static
+void fill_sector(void)
+{
+	long curpos;
+
+	if ((curpos = ftell(outfile)) == -1)
+		die(1,"File error %s: %s\n", outfilename, strerror(errno));
+
+	for (int i = 0; i < 128 - curpos % 128; i++)
+		if (fputc(0, outfile) == EOF)
+			die(1,"Error writing output file %s: %s\n",
+					outfilename, strerror(errno));
+
+	return;
+}
+
+
+static
+int process_prlfile(void)
+{
+	fgetc(prlfile);
+	progsize = fgetc(prlfile) + (fgetc(prlfile) << 8);
+
+	/* skip header */
+	fseek(prlfile, 0x100, SEEK_SET);
+
+	for (unsigned i = 0; i < progsize; i++) {
+		int c = fgetc(prlfile);
+		if (c == EOF)
+			die(1,"Unexpected end of prl file %s\n", prlfilename);
+		if (fputc(c, outfile) == EOF)
+			die(1,"Error writing output file %s: %s\n",
+					outfilename, strerror(errno));
+	}
+
+
+	int bits;
+	while ((bits = get_nr_of_bits()) >= 2) {
+		unsigned off = bits - 2;
+		if (off < (1<<2)) {
+			put_bits(0 + 2 + 1, off);
+		} else if (off < (1<<4) + (1<<2)) {
+			off -= (1<<2);
+			off += (1<<(4+1));
+			put_bits(1 + 4 + 1, off);
+		} else if (off < (1<<8) + (1<<4) + (1<<2)) {
+			off -= (1<<4) + (1<<2);
+			off += (1<<(8+1));
+			off += (1<<(8+2));
+			put_bits(2 + 8 + 1, off);
+		} else {
+			off -= (1<<8) + (1<<4) + (1<<2);
+			off += (1<<(16+1));
+			off += (1<<(16+2));
+			off += (1<<(16+3));
+			put_bits(3 + 16 + 1, off);
+		}
+	}
+
+	if (bits == 1)
+			die(1,"Bitmap error");
+
+	if (bits < 0)
+			die(1,"Error while reading bitmap from prl file %s\n", prlfilename);
+
+	/* end mark */
+	put_bits(4, 0xf);
+
+	/* flush output bit buffer */
+	put_bits(7, 0);
+
+	fill_sector();
+
+	return 0;
+}
+
+static
+void usage(void)
+{
+	fprintf(stderr,
+"Usage:\n"
+"%s prlfile outfile\n", progname);
+
+}
+
+int main(int argc, char **argv)
+{
+	progname = argv[0];
+
+	if (argc != 3) {
+		usage();
+		die(1, "");
+	}
+
+	prlfilename = argv[1];
+	prlfile=fopen(prlfilename,"rb");
+	if (prlfile==NULL)
+		die(1,"Cannot open prl file %s: %s\n",
+				prlfilename, strerror(errno));
+
+	outfilename = argv[2];
+	outfile=fopen(outfilename,"wb");
+	if (outfile==NULL)
+		die(1,"Cannot open output file %s: %s\n",
+				outfilename, strerror(errno));
+
+	process_prlfile();
+	fclose(prlfile);
+	fclose(outfile);
+
+	return 0;
+}
-- 
2.39.2