From 637df6ee3356a7fc111956430ab7e8524037aac1 Mon Sep 17 00:00:00 2001
From: Kelvin Sherlock <ksherlock@gmail.com>
Date: Sun, 15 Dec 2019 13:04:45 -0500
Subject: [PATCH] ORG and LKV 1 support (untested)

---
 link.cpp | 21 ++++++++++++++++++---
 omf.cpp  | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/link.cpp b/link.cpp
index cb2564a..d050194 100644
--- a/link.cpp
+++ b/link.cpp
@@ -31,6 +31,8 @@
 #include "script.h"
 
 void save_omf(const std::string &path, std::vector<omf::segment> &segments, bool compress, bool expressload);
+void save_bin(const std::string &path, omf::segment &segment, uint32_t org);
+
 int set_file_type(const std::string &path, uint16_t file_type, uint32_t aux_type, std::error_code &ec);
 void set_file_type(const std::string &path, uint16_t file_type, uint32_t aux_type);
 
@@ -594,8 +596,14 @@ void finish(void) {
 	std::string path = save_file;
 
 	if (path.empty()) path = "gs.out";
+
+
 	try {
-		save_omf(path, segments, compress, express);
+		if (lkv == 0)
+			save_bin(path, segments.back(), org);
+		else
+			save_omf(path, segments, compress, express);
+
 		set_file_type(path, ftype, atype);
 	} catch (std::exception &ex) {
 		errx(EX_OSERR, "%s: %s", path.c_str(), ex.what());
@@ -743,6 +751,12 @@ void evaluate(label_t label, opcode_t opcode, const char *cursor) {
 		case OP_ADR:
 			atype = number_operand(cursor, local_symbol_table);
 			break;
+
+		case OP_ORG:
+			org = number_operand(cursor, local_symbol_table);
+			atype = org;
+			break;
+
 		case OP_KND: {
 			uint32_t kind = number_operand(cursor, local_symbol_table);
 			if (!segments.empty())
@@ -773,8 +787,8 @@ void evaluate(label_t label, opcode_t opcode, const char *cursor) {
 
 			uint32_t value = number_operand(cursor, local_symbol_table);
 			switch (value) {
-				case 0: throw std::runtime_error("binary linker not supported");
 				case 3: throw std::runtime_error("object file linker not supported");
+				case 0:
 				case 1:
 				case 2:
 					lkv = value;
@@ -841,7 +855,8 @@ void evaluate(label_t label, opcode_t opcode, const char *cursor) {
 				seg.loadname = base;
 				// seg.kind = kind;
 			}
-			if (lkv == 1) {
+
+			if (lkv == 0 || lkv == 1) {
 				finish();
 				// reset.  could have another link afterwards.
 				segments.clear();
diff --git a/omf.cpp b/omf.cpp
index 65af576..8853e1e 100644
--- a/omf.cpp
+++ b/omf.cpp
@@ -351,6 +351,38 @@ uint32_t add_relocs(std::vector<uint8_t> &data, size_t data_offset, omf::segment
 	return reloc_size;
 }
 
+void save_bin(const std::string &path, omf::segment &segment, uint32_t org) {
+
+	int fd;
+	fd = open(path.c_str(), O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0666);
+	if (fd < 0) {
+		err(EX_CANTCREAT, "Unable to open %s", path.c_str());
+	}
+
+	auto &data = segment.data;
+
+	for (auto &r : segment.relocs) {
+
+		uint32_t value = r.value + org;
+		value >>= -(int8_t)r.shift;
+
+		unsigned offset = r.offset;
+		unsigned size = r.size;
+		while (size--) {
+			data[offset++] = value & 0xff;
+			value >>= 8;
+		}
+	}
+
+	auto ok = write(fd, data.data(), data.size());
+	if (ok < 0) {
+		close(fd);
+		err(EX_OSERR, "write %s", path.c_str());
+	}
+	close(fd);
+}
+
+
 void save_omf(const std::string &path, std::vector<omf::segment> &segments, bool compress, bool expressload) {
 
 	// expressload doesn't support links to other files.