From 471c4d4151389db0872a5eb8e51273f3173054b0 Mon Sep 17 00:00:00 2001
From: Kelvin Sherlock <ksherlock@gmail.com>
Date: Thu, 8 Dec 2022 18:37:36 -0500
Subject: [PATCH] fixes so omf version 1 support works

---
 link.cpp | 18 +++++++++++++-----
 omf.cpp  |  9 ++++++++-
 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/link.cpp b/link.cpp
index e274ff9..74603b3 100644
--- a/link.cpp
+++ b/link.cpp
@@ -798,7 +798,7 @@ void finish(void) {
 		if (lkv == 0)
 			save_bin(path, segments.back());
 		else
-			save_omf(path, segments, compress, express);
+			save_omf(path, segments, compress, express, ver);
 
 		set_file_type(path, ftype, atype);
 	} catch (std::exception &ex) {
@@ -903,7 +903,11 @@ void finish3(void) {
 
 				push(buffer, omf::opcode::GEQU);
 				push(buffer, sym.name);
-				push(buffer, static_cast<uint16_t>(0x00)); /* length attr */
+				if (ver == 1) {
+					push(buffer, static_cast<uint8_t>(0x00)); /* length attr */
+				} else {
+					push(buffer, static_cast<uint16_t>(0x00)); /* length attr */
+				}
 				push(buffer, static_cast<uint8_t>('G')); /* type attr */
 				push(buffer, static_cast<uint32_t>(sym.value));
 			} else {
@@ -969,7 +973,11 @@ void finish3(void) {
 				/* add global record */
 				push(buffer, omf::opcode::GLOBAL);
 				push(buffer, iter1->second); /* name */
-				push(buffer, static_cast<uint16_t>(0x00)); /* length attr */
+				if (ver == 1) {
+					push(buffer, static_cast<uint8_t>(0x00)); /* length attr */
+				} else {
+					push(buffer, static_cast<uint16_t>(0x00)); /* length attr */
+				}
 				push(buffer, static_cast<uint8_t>('N')); /* type attr */
 				push(buffer, static_cast<uint8_t>(0x00)); /* public */
 				++iter1;
@@ -1006,7 +1014,7 @@ void finish3(void) {
 	if (iter3 != resolved.end())
 		throw std::runtime_error("relocation offset error");
 
-	void save_object(const std::string &path, omf::segment &s, uint32_t length);
+	void save_object(const std::string &path, omf::segment &s, uint32_t length, unsigned version);
 
 
 	std::string path = save_file;
@@ -1014,7 +1022,7 @@ void finish3(void) {
 	if (verbose) printf("Saving %s\n", path.c_str());
 
 	try {
-		save_object(path, seg, pc);
+		save_object(path, seg, pc, ver);
 		set_file_type(path, 0xb1, 0x0000);
 	} catch (std::exception &ex) {
 		errx(EX_OSERR, "%s: %s", path.c_str(), ex.what());
diff --git a/omf.cpp b/omf.cpp
index 828190e..924df28 100644
--- a/omf.cpp
+++ b/omf.cpp
@@ -490,7 +490,7 @@ void save_bin(const std::string &path, omf::segment &segment) {
 	close(fd);
 }
 
-void save_object(const std::string &path, omf::segment &s, uint32_t length) {
+void save_object(const std::string &path, omf::segment &s, uint32_t length, unsigned version) {
 
 	/* data is already in OMF format. */
 
@@ -521,6 +521,7 @@ void save_object(const std::string &path, omf::segment &s, uint32_t length) {
 	h.bytecount = sizeof(omf_header) + data.size() + s.data.size();
 
 	unsigned offset = 0;
+	if (version == 1) to_v1(h);
 	to_little(h);
 	offset += write(fd, &h, sizeof(h));
 	offset += write(fd, data.data(), data.size());
@@ -669,6 +670,12 @@ void save_omf(const std::string &path, std::vector<omf::segment> &segments, bool
 		to_little(h);
 		offset += write(fd, &h, sizeof(h));
 		offset += write(fd, data.data(), data.size());
+
+		// version 1 needs 512-byte padding for all but final segment.
+		if (version == 1 && &s != &segments.back()) {
+			static uint8_t zero[512];
+			offset += write(fd, zero, 512 - (offset & 511) );
+		}
 	}
 
 	if (expressload) {