added a.out conversion program

tools/ml.c

@@ -0,0 +1,224 @@
+/*
+ * Quick hack to read old unix a.out files and make
+ * a simh "load file".
+ *
+ * Brad Parker <brad@heeltoe.com> 5/2008
+ */
+#include <stdio.h>
+#include <fcntl.h>
+#include <stdlib.h>
+
+/* Binary loader.
+
+   Loader format consists of blocks, optionally preceded, separated, and
+   followed by zeroes.  Each block consists of:
+
+        001             ---
+        xxx              |
+        lo_count         |
+        hi_count         |
+        lo_origin        > count bytes
+        hi_origin        |
+        data byte        |
+        :                |
+        data byte       ---
+        checksum
+
+   If the byte count is exactly six, the block is the last on the tape, and
+   there is no checksum.  If the origin is not 000001, then the origin is
+   the PC at which to start the program.
+*/
+
+typedef unsigned short u16;
+
+struct exec {
+        u16   a_magic;
+        u16   a_text;
+        u16   a_data;
+        u16   a_bss;
+        u16   a_syms;
+        u16   a_entry;
+        u16   a_unused;
+        u16   a_flag;
+};
+
+unsigned char buffer[1024];
+int checksum;
+
+int verbose;
+
+int
+mk_hdr(int fd, int count, int origin)
+{
+	int i, ret, hc;
+
+	checksum = 0;
+	hc = count + 6;
+
+	buffer[0] = 0x01;
+	buffer[1] = 0x00;
+	buffer[2] = hc & 0xff;
+	buffer[3] = hc >> 8;
+	buffer[4] = origin & 0xff;
+	buffer[5] = origin >> 8;
+
+	ret = write(fd, buffer, 6);
+	if (ret != 6)
+		return -1;
+
+	for (i = 0; i < 6; i++)
+		checksum += buffer[i] & 0xff;
+
+	return 0;
+}
+
+int
+mk_post_data(int fd)
+{
+	int ret, final_checksum;
+
+	/* final checksum must be zero */
+	final_checksum = 256 - (checksum & 0xff);
+
+	buffer[0] = final_checksum;
+	if (verbose)
+		printf("checksum %08x, final %02x\n", checksum, final_checksum);
+
+	ret = write(fd, buffer, 1);
+	if (ret != 1)
+		return -1;
+
+	return 0;
+}
+
+int
+load(int fd, char *buf, int bufsize)
+{
+	int i, ret;
+
+	printf("load: %d bytes\n", bufsize);
+
+	if (bufsize < 65536) {
+		mk_hdr(fd, bufsize, 0);
+
+		ret = write(fd, buf, bufsize);
+		if (ret != bufsize)
+			return -1;
+
+		for (i = 0; i < bufsize; i++)
+			checksum += buf[i] & 0xff;
+
+		mk_post_data(fd);
+	}
+
+	return 0;
+}
+
+int
+finish(int fd, int origin)
+{
+	mk_hdr(fd, 0, origin);
+}
+
+int
+process_aout(int ifd, int ofd, int origin)
+{
+	int ret, hdr_size;
+	struct exec hdr;
+	char *textblob, *datablob;
+
+	ret = read(ifd, (char *)&hdr, sizeof(hdr));
+	if (ret != sizeof(hdr)) {
+		return -1;
+	}
+
+	if (1) {
+		printf("magic 0%o\ntext %d, data %d, bss %d, syms %d\n",
+		       hdr.a_magic & 0xffff,
+		       hdr.a_text, hdr.a_data, hdr.a_bss, hdr.a_syms);
+		printf("entry %o, flag %o\n",
+		       hdr.a_entry,
+		       hdr.a_flag);
+	}
+
+	textblob = malloc(hdr.a_text);
+	datablob = malloc(hdr.a_data);
+
+	hdr_size = 0;
+
+	/* v7 header? if so, 0 is after header */
+	switch (hdr.a_magic) {
+	case 0407: hdr_size = 0; break;
+	case 0405: hdr_size = 12; break;
+	}
+
+	if (hdr_size) {
+		/* back up */
+		lseek(ifd, (off_t)-hdr_size, SEEK_CUR);
+		hdr.a_text += hdr_size;
+	}
+
+	ret = read(ifd, textblob, hdr.a_text);
+	if (ret != hdr.a_text)
+		return -1;
+
+	ret = read(ifd, datablob, hdr.a_data);
+	if (ret != hdr.a_data)
+		return -1;
+
+	load(ofd, textblob, hdr.a_text);
+	load(ofd, datablob, hdr.a_data);
+
+	finish(ofd, origin);
+
+	return 0;
+
+}
+
+int
+process(char *inf, char *outf)
+{
+	int ifd, ofd, ret;
+	int origin;
+
+	ofd = open(outf, O_WRONLY | O_CREAT, 0666);
+	if (ofd < 0) {
+		perror(outf);
+		return -1;
+	}
+
+	ifd = open(inf, O_RDONLY);
+	if (ifd < 0) {
+		perror(inf);
+		close(ofd);
+		return -1;
+	}
+
+	ret = 0;
+	origin = 0;
+
+	if (process_aout(ifd, ofd, origin)) {
+		ret = -1;
+	}
+
+	close(ifd);
+	close(ofd);
+
+	return ret;
+}
+
+
+main(int argc, char *argv[])
+{
+	char *filename = "a.out";
+	char *output_filename = "loadfile";
+	int fd;
+
+	verbose = 0;
+
+	if (process(filename, output_filename)) {
+		fprintf(stderr, "%s: failed?\n", filename);
+	}
+
+	exit(0);
+}