diff --git a/Makefile b/Makefile
index 6db3f56..937a589 100644
--- a/Makefile
+++ b/Makefile
@@ -2,20 +2,28 @@ LINK.o = $(LINK.cc)
 CXXFLAGS = -std=c++11 -g -Wall
 CCFLAGS = -g
 
-OBJS = dumpobj.o disassembler.o zrdz_disassembler.o
+DUMP_OBJS = dumpobj.o disassembler.o zrdz_disassembler.o
+LINK_OBJS = link.o expression.o
 
 #UNAME_S := $(shell uname -s)
 #ifeq ($(UNAME_S),MINGW64_NT-10.0)
 ifeq ($(MSYSTEM),MINGW64)
-	OBJS += mingw/err.o
+	DUMP_OBJS += mingw/err.o
+	LINK_OBJS += mingw/err.o
 	CPPFLAGS += -I mingw/
 	LDLIBS += -static
 endif
 
+.PHONY: all
+all: wdcdumpobj wdclink
 
-wdcdumpobj : $(OBJS)
+wdcdumpobj : $(DUMP_OBJS)
 	$(LINK.o) $^ $(LDLIBS) -o $@
 
+wdclink : $(LINK_OBJS)
+	$(LINK.o) $^ $(LDLIBS) -o $@
+
+
 disassembler.o : disassembler.cpp disassembler.h
 zrdz_disassembler.o : zrdz_disassembler.cpp zrdz_disassembler.h disassembler.h
 dumpobj.o : dumpobj.cpp zrdz_disassembler.h disassembler.h
@@ -23,7 +31,7 @@ mingw/err.o : mingw/err.c mingw/err.h
 
 .PHONY: clean
 clean:
-	$(RM) wdcdumpobj $(OBJS)
+	$(RM) wdcdumpobj $(DUMP_OBJS) $(LINK_OBJS)
 
 
 .PHONY: variables
diff --git a/dumpobj.cpp b/dumpobj.cpp
index 5e2969b..fa5fe0e 100644
--- a/dumpobj.cpp
+++ b/dumpobj.cpp
@@ -72,7 +72,7 @@ void usage() {
 struct Header {
 	uint32_t magic;				/* magic number for detection */
 	uint16_t version;			/* version number of object format */
-	uint8_t filetype;				/* file type, object or library */
+	uint8_t filetype;			/* file type, object or library */
 };
 
 #pragma pack(pop)
diff --git a/expression.cpp b/expression.cpp
new file mode 100644
index 0000000..abb1c58
--- /dev/null
+++ b/expression.cpp
@@ -0,0 +1,169 @@
+#include "expression.h"
+#include <vector>
+#include "obj816.h"
+
+/* a ** b */
+uint32_t power(uint32_t a, uint32_t b) {
+
+	uint32_t rv = 1;
+	for( ; b; b >>= 1) {
+		if (b & 0x01) rv *= a;
+		a = a * a;
+	}
+	return rv; 
+}
+
+bool unary_op(unsigned op, std::vector<expr> &v) {
+	if (v.size() >=1 ) {
+		expr &a = v.back();
+		if (a.tag == OP_VAL) {
+			switch(a.tag) {
+			case OP_NOT: a.value = !a.value; break;
+			case OP_NEG: a.value = -a.value; break;
+			case OP_FLP: a.value = ~a.value; break;
+			}
+			return true;
+		}
+	}
+	v.emplace_back(op);
+	return false;
+}
+
+
+bool binary_op(unsigned op, std::vector<expr> &v) {
+	if (v.size() >= 2) {
+		expr &a = v[v.size() - 2];
+		expr &b = v[v.size() - 1];
+
+		if (a.tag == OP_VAL && b.tag == OP_VAL) {
+			uint32_t value = 0;
+			switch(op) {
+			case OP_EXP: value = power(a.value, b.value); break;
+			case OP_MUL: value = a.value * b.value; break;
+			case OP_DIV: value = a.value / b.value; break;
+			case OP_MOD: value = a.value % b.value; break;
+			case OP_SHR: value = a.value >> b.value; break;
+			case OP_SHL: value = a.value << b.value; break;
+			case OP_ADD: value = a.value + b.value; break;
+			case OP_SUB: value = a.value - b.value; break;
+			case OP_AND: value = a.value & b.value; break;
+			case OP_OR: value = a.value | b.value; break;
+			case OP_XOR: value = a.value ^ b.value; break;
+			case OP_EQ: value = a.value == b.value; break;
+			case OP_GT: value = (int32_t)a.value > (int32_t)b.value; break;
+			case OP_LT: value = (int32_t)a.value < (int32_t)b.value; break;
+			case OP_UGT: value = a.value > b.value; break;
+			case OP_ULT: value = a.value < b.value; break;
+			}
+			v.pop_back();
+			v.back().value = value;
+			return true;
+		}
+		if (a.tag == OP_VAL && b.tag == OP_LOC) {
+			switch(op) {
+				case OP_ADD: {
+					// constant + symbol
+					expr tmp = b;
+					tmp.value = a.value + b.value;
+					v.pop_back();
+					v.pop_back();
+					v.emplace_back(tmp);
+					return true; 
+				}
+				#if 0
+				case OP_SUB: {
+					// constant - symbol .. does this even make sense?
+					expr tmp = b;
+					tmp.value = a.value - b.value;
+					v.pop_back();
+					v.pop_back();
+					v.emplace_back(tmp);
+					return true; 
+				}
+				#endif
+			}
+		}
+		if (a.tag == OP_LOC && b.tag == OP_VAL) {
+			switch(op) {
+				case OP_ADD: a.value += b.value; return true;
+				case OP_SUB: a.value -= b.value; return true;
+			}
+		}
+
+		if (a.tag == OP_LOC && b.tag == OP_LOC && a.section == b.section) {
+			uint32_t value = 0;
+			bool rv = false;
+			switch (op) {
+				case OP_SUB:
+					// end - start
+					value = a.value - b.value;
+					rv = true; break;
+				case OP_EQ:
+					value = a.value == b.value;
+					rv = true; break;
+				case OP_GT:
+				case OP_UGT:
+					value = a.value > b.value;
+					rv = true; break;
+				case OP_LT:
+				case OP_ULT:
+					value = a.value < b.value;
+					rv = true; break;
+			}
+			if (rv) {
+				v.pop_back();
+				v.pop_back();
+				v.emplace_back(OP_VAL, value);
+				return true;
+			}
+		}
+
+
+	}
+	v.emplace_back(op);
+	return false;
+}
+
+
+bool simplify_expression(expression &e) {
+	std::vector<expr> tmp;
+	bool rv = false;
+	for (auto &t : e.stack) {
+		if (t.tag >= OP_BIN) {
+			rv = binary_op(t.tag, tmp) || rv;
+		} else if (t.tag >= OP_UNA) {
+			rv = unary_op(t.tag, tmp) || rv;
+		} else {
+			tmp.emplace_back(t);
+		}
+	}
+	if (rv) e.stack = std::move(tmp);
+	return rv;
+}
+
+/* 
+ * if force is true, treat OP_LOC records as OP_VAL (for omf)
+ */
+
+// should return std::optional<uint32_t>...
+
+uint32_t evaluate_expression(expression &e, bool force) {
+	std::vector<expr> tmp;
+	for (const auto &t : e.stack) {
+		if (t.tag == OP_LOC && force) {
+			tmp.emplace_back(OP_VAL, t.value);
+			continue;				
+		}
+		if (t.tag >= OP_BIN) {
+			binary_op(t.tag, tmp);
+		} else if (t.tag >= OP_UNA) {
+			unary_op(t.tag, tmp);
+		} else {
+			tmp.emplace_back(t);
+		}
+	}
+
+	if (tmp.size() == 1 && tmp.front().tag == OP_VAL) return tmp.front().value;
+	return 0;
+}
+
diff --git a/expression.h b/expression.h
new file mode 100644
index 0000000..db3c56d
--- /dev/null
+++ b/expression.h
@@ -0,0 +1,32 @@
+#ifndef __expression_h__
+#define __expression_h__
+
+#include <stdint.h>
+#include <vector>
+
+struct expr {
+	expr(int t = 0, uint32_t v = 0, uint32_t s = 0)
+		: tag(t), value(v), section(s)
+	{}
+	int tag = 0;
+	uint32_t value = 0;
+	unsigned section = 0;
+};
+
+
+struct expression {
+	unsigned section = 0;
+	uint32_t offset = 0;
+	uint8_t size = 0;
+	uint8_t relative = false;
+	bool undefined = false;
+
+	std::vector<expr> stack;
+
+};
+
+uint32_t evaluate_expression(expression &e, bool force = false);
+
+bool simplify_expression(expression &e);
+
+#endif
diff --git a/link.cpp b/link.cpp
index ff9efb1..9c274ad 100644
--- a/link.cpp
+++ b/link.cpp
@@ -7,7 +7,818 @@
 #include <sysexits.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <fcntl.h>
 #include <err.h>
+#include <assert.h>
+#include <stdio.h>
+
+#include <string>
+#include <vector>
+#include <algorithm>
+#include <unordered_map>
+#include <unordered_set>
+#include <array>
+#include <utility>
+#include <numeric>
+#include <iterator>
+
+#include "obj816.h"
+#include "expression.h"
+
+
+#ifndef O_BINARY
+#define O_BINARY 0
+#endif
+
+enum class endian {
+	little = __ORDER_LITTLE_ENDIAN__,
+	big = __ORDER_BIG_ENDIAN__,
+	native = __BYTE_ORDER__
+};
+
+
+template<class T>
+void swap_if(T &t, std::false_type) {}
+
+void swap_if(uint8_t &, std::true_type) {}
+
+void swap_if(uint16_t &value, std::true_type) {
+	value = __builtin_bswap16(value);
+}
+
+void swap_if(uint32_t &value, std::true_type) {
+	value = __builtin_bswap32(value);
+}
+
+void swap_if(uint64_t &value, std::true_type) {
+	value = __builtin_bswap64(value);
+}
+
+template<class T>
+void le_to_host(T &value) {
+	swap_if(value, std::integral_constant<bool, endian::native == endian::big>{});
+}
+
+
+#pragma pack(push, 1)
+struct Header {
+	uint32_t magic;				/* magic number for detection */
+	uint16_t version;			/* version number of object format */
+	uint8_t filetype;			/* file type, object or library */
+};
+
+#pragma pack(pop)
+
+
+struct section {
+	std::string name;
+	uint8_t flags = 0;
+	uint32_t org = 0;
+	uint32_t size = 0;
+
+	unsigned number = -1;
+	std::vector<uint8_t> data;
+	std::vector<expression> expressions;
+
+	unsigned end_symbol = 0; // auto-generated _END_{name} symbol.
+};
+
+struct symbol {
+	std::string name;
+	uint8_t type = 0;
+	uint8_t flags = 0;
+	uint32_t offset = 0;
+	int section = -1;
+};
+
+template<class T>
+uint8_t read_8(T &iter) {
+	uint8_t tmp = *iter;
+	++iter;
+	return tmp;
+}
+
+template<class T>
+uint16_t read_16(T &iter) {
+	uint16_t tmp = 0;
+
+	tmp |= *iter << 0;
+	++iter;
+	tmp |= *iter << 8;
+	++iter;
+	return tmp;
+}
+
+template<class T>
+uint32_t read_32(T &iter) {
+	uint32_t tmp = 0;
+
+	tmp |= *iter << 0;
+	++iter;
+	tmp |= *iter << 8;
+	++iter;
+	tmp |= *iter << 16;
+	++iter;
+	tmp |= *iter << 24;
+	++iter;
+
+
+	return tmp;
+}
+
+template<class T>
+std::string read_cstring(T &iter) {
+	std::string s;
+	for(;;) {
+		uint8_t c = *iter;
+		++iter;
+		if (!c) break;
+		s.push_back(c);
+	}
+	return s;
+}
+
+
+template<class T>
+std::string read_pstring(T &iter) {
+	std::string s;
+	unsigned  size = *iter;
+	++iter;
+	s.reserve(size);
+	while (size--) {
+		uint8_t c = *iter;
+		++iter;
+		s.push_back(c);
+	}
+	return s;
+}
+
+
+std::vector<section> read_sections(const std::vector<uint8_t> &section_data) {
+
+	std::vector<section> sections;
+	auto iter = section_data.begin();
+	while (iter != section_data.end()) {
+
+		section s;
+
+		s.number = read_8(iter);
+		s.flags = read_8(iter);
+		s.size = read_32(iter);
+		s.org = read_32(iter);
+
+		if (!(s.flags & SEC_NONAME)) s.name = read_cstring(iter);
+
+		sections.emplace_back(std::move(s));
+	}
+	return sections;
+}
+
+
+std::vector<symbol> read_symbols(const std::vector<uint8_t> &symbol_data) {
+
+	std::vector<symbol> symbols;
+
+	auto iter = symbol_data.begin();
+	while (iter != symbol_data.end()) {
+		symbol s;
+		s.type = read_8(iter);
+		s.flags = read_8(iter);
+		s.section = read_8(iter);
+		s.offset = s.type == S_UND ? 0 : read_32(iter);
+		s.name = read_cstring(iter);
+
+
+		symbols.emplace_back(std::move(s));
+	}
+
+	return symbols;
+}
+
+
+std::unordered_map<std::string, int> section_map;
+std::vector<section> sections;
+
+std::unordered_map<std::string, int> symbol_map;
+std::vector<symbol> symbols;
+
+std::unordered_set<std::string> undefined_symbols;
+
+
+
+
+
+/*
+ * replace undefined symbols (if possible) and simplify expressions.
+ *
+ */
+void simplify() {
+	for (auto &s : sections) {
+		for (auto &e : s.expressions) {
+			bool delta = false;
+
+			// first check for undefined symbols.
+			if (e.undefined) {
+				e.undefined = false;
+				for (auto &t : e.stack) {
+
+					if (t.tag == OP_SYM) {
+						const auto &ss = symbols[t.section];
+						switch(ss.type & 0x0f) {
+							case S_UND:
+								e.undefined = true;
+								break;
+							case S_REL:
+								t = expr{OP_LOC, ss.offset, (uint32_t)ss.section};
+								delta = true;
+								break;
+							case S_ABS:
+								t = expr{OP_VAL, (uint32_t)ss.offset};
+								delta = true;
+								break;
+						}
+					}
+				}
+			}
+			if (e.stack.size() > 1) simplify_expression(e);
+		}
+	}
+}
+
+
+
+/*
+ * read and process all sections...
+ * if section > 5, remap based on name.
+ *
+ */
+
+void one_module(const std::vector<uint8_t> &data, const std::vector<uint8_t> &section_data, const std::vector<uint8_t> &symbol_data) {
+
+	std::array<int, 256> remap_section;
+
+	int current_section = SECT_CODE;
+	std::vector<uint8_t> *data_ptr = &sections[current_section].data;
+
+	std::fill(remap_section.begin(), remap_section.end(), -1);
+	remap_section[SECT_PAGE0] = SECT_PAGE0;
+	remap_section[SECT_CODE] = SECT_CODE;
+	remap_section[SECT_KDATA] = SECT_KDATA;
+	remap_section[SECT_DATA] = SECT_DATA;
+	remap_section[SECT_UDATA] = SECT_UDATA;
+
+	std::vector<section> local_sections = read_sections(section_data);
+	std::vector<symbol> local_symbols = read_symbols(symbol_data);
+
+	// convert local sections to global 
+	for (auto &s : local_sections) {
+		if (s.number <= SECT_UDATA) continue;
+
+		auto iter = section_map.find(s.name);
+		if (iter == section_map.end()) {
+			int virtual_section = sections.size();
+			remap_section[s.number] = virtual_section;
+			s.number = virtual_section;
+			sections.emplace_back(s);
+			symbol_map.emplace(s.name, virtual_section);
+		} else {
+			const auto &ss = sections[iter->second];
+			assert(ss.flags == s.flags); // check org????
+			remap_section[s.number] = iter->second;
+			s.number = iter->second;
+		}
+	}
+
+	// convert local symbols to global.
+	for (auto &s : local_symbols) {
+		if (s.type == S_UND) {
+			auto iter = symbol_map.find(s.name);
+			if (iter == symbol_map.end()) {
+				s.section = symbols.size();
+				symbol_map.emplace(s.name, s.section);
+				undefined_symbols.emplace(s.name);
+			}
+			else {
+				// already exists... 
+				const auto &ss = symbols[iter->second];
+				if (ss.type != S_UND) s = ss;
+			}
+			continue;
+		}
+
+		// remap and fudge the offset.
+		if ((s.type & 0x0f) == S_REL) {
+			int virtual_section = remap_section[s.section];
+			assert(virtual_section != -1);
+			s.section = virtual_section;
+			s.offset += sections[virtual_section].data.size();
+		} else {
+			s.section = -1;
+		}
+
+		constexpr const unsigned mask = SF_GBL | SF_DEF;
+		if ((s.flags & mask) == mask) {
+
+			auto iter = symbol_map.find(s.name);
+
+			if (iter == symbol_map.end()) {
+				unsigned tmp = symbols.size();
+				symbol_map.emplace(s.name, tmp);
+				symbols.emplace_back(s);
+			} else {
+				auto &ss = symbols[iter->second];
+
+				// if it was undefined, define it!
+				if (ss.type == S_UND) {
+					ss = s;
+					undefined_symbols.erase(s.name);
+				}
+				else {
+					// ok if symbols are identical..
+					assert(ss.type == ss.type && ss.flags == s.flags && ss.section == s.section && ss.offset == s.offset);
+				}
+			}
+
+		}
+
+	}
+
+
+	auto iter = data.begin();
+	for(;;) {
+		uint8_t op = read_8(iter);
+		if (op == REC_END) return;
+
+		++iter;
+		if (op < 0xf0) {
+			data_ptr->insert(data_ptr->end(), iter, iter + op);
+			iter += op;
+			continue;
+		}
+
+		switch(op) {
+			case REC_SPACE: {
+				uint16_t count = read_16(iter);
+				data_ptr->insert(data_ptr->end(), count, 0);
+				break;
+			}
+
+			case REC_SECT: {
+				/* switch sections */
+				uint8_t s = read_8(iter);
+				current_section = remap_section[s];
+				assert(current_section > 0 && current_section < sections.size());
+
+				data_ptr = &sections[current_section].data;
+				break;
+			}
+
+			case REC_ORG: {
+				assert(!"ORG not supported.");
+				break;
+			}
+
+			case REC_RELEXP:
+			case REC_EXPR: {
+
+				expression e;
+				e.relative = op == REC_RELEXP;
+
+				e.offset =  data_ptr->size();
+				e.size = read_8(iter);
+
+				data_ptr->insert(data_ptr->end(), e.size, 0);
+
+				/**/
+				for(;;) {
+					op = read_8(iter);
+					if (op == OP_END) break;
+
+					switch(op) {
+						case OP_VAL: {
+							uint32_t offset = read_32(iter);
+							e.stack.emplace_back(op, offset);
+							break;
+						}
+						case OP_SYM: {
+							uint16_t symbol = read_16(iter);
+							assert(symbol < local_symbols.size());
+							auto &s = local_symbols[symbol];
+							switch (s.type & 0x0f) {
+								case S_UND:
+									// S_UND indicates it's still undefined globally.
+									e.stack.emplace_back(OP_SYM, 0, s.section); /* section is actually a symbol number */
+									e.undefined = true;
+									break;
+								case S_REL:
+									e.stack.emplace_back(OP_LOC, s.offset, s.section);
+									break;
+
+								case S_ABS:
+									e.stack.emplace_back(OP_VAL, s.offset);
+									break;
+
+								default:
+									assert(!"unsupported symbol flags.");
+							}
+							break;
+						}
+						case OP_LOC: {
+							uint8_t section = read_8(iter);
+							uint32_t offset = read_32(iter);
+							int real_section = remap_section[section];
+							assert(real_section >= 0);
+							e.stack.emplace_back(op, offset, real_section);
+							break;
+						}
+						// operations..
+						//unary
+						case OP_NOT:
+						case OP_NEG:
+						case OP_FLP:
+						// binary
+						case OP_EXP:
+						case OP_MUL:
+						case OP_DIV:
+						case OP_MOD:
+						case OP_SHR:
+						case OP_SHL:
+						case OP_ADD:
+						case OP_SUB:
+						case OP_AND:
+						case OP_OR:
+						case OP_XOR:
+						case OP_EQ:
+						case OP_GT:
+						case OP_LT:
+						case OP_UGT:
+						case OP_ULT:
+							e.stack.emplace_back(op);
+							break;
+						default:
+							assert(!"unsupported expression opcode.");
+					}
+				}
+				break;
+			}
+
+
+			case REC_LINE: break;
+			case REC_DEBUG: {
+				uint16_t size = read_16(iter);
+				iter += size;
+				break;		
+			}
+
+		}
+	}
+}
+
+
+
+void init() {
+
+	sections.resize(5);
+
+	sections[SECT_PAGE0].number = SECT_PAGE0;
+	sections[SECT_PAGE0].flags = SEC_DATA | SEC_NONAME | SEC_DIRECT | SEC_REF_ONLY;
+	sections[SECT_PAGE0].name = "page0";
+
+	sections[SECT_CODE].number = SECT_CODE;
+	sections[SECT_CODE].flags = SEC_NONAME;
+	sections[SECT_CODE].name = "code"; 
+
+	sections[SECT_KDATA].number = SECT_KDATA;
+	sections[SECT_KDATA].flags = SEC_DATA | SEC_NONAME;
+	sections[SECT_KDATA].name = "kdata"; 
+
+	sections[SECT_DATA].number = SECT_DATA;
+	sections[SECT_DATA].flags = SEC_DATA | SEC_NONAME;
+	sections[SECT_DATA].name = "data"; 
+
+	sections[SECT_UDATA].number = SECT_UDATA;
+	sections[SECT_UDATA].flags = SEC_DATA | SEC_NONAME | SEC_REF_ONLY;
+	sections[SECT_UDATA].name = "udata"; 
+
+	/*
+	 * For each section, [the linker] creates three symbols, 
+	 * _ROM_BEG_secname, _BEG_secname and _END_secname, which
+	 * correspond to the rom location and the execution beginning
+	 * and end of the section. These will be used more in the next
+	 * two sections of code.
+	 */
+
+	// n.b - only for pre-defined sections [?], skip the _ROM_BEG_* symbols...
+
+	static std::string names[] = {
+			"_BEG_PAGE0", "_END_PAGE0",
+			"_BEG_CODE", "_END_CODE",
+			"_BEG_KDATA", "_END_KDATA"
+			"_BEG_DATA", "_END_DATA"
+			"_BEG_UDATA", "_END_UDATA"
+	};
+
+	for (int i = 0; i < 5; ++i) {
+
+		// begin is 0.
+		symbol s;
+		s.name = names[i * 2];
+		s.section = i;
+		s.type = S_REL;
+		s.flags = SF_DEF | SF_GBL;
+		symbol_map.emplace(s.name, i * 2);
+		symbols.emplace_back(s);
+
+		// end is undefined...
+		s.name = names[i * 2 + 1];
+		s.section = i * 2 + 1; // symbol number.
+		s.type = S_UND;
+		s.flags = 0;
+
+		symbol_map.emplace(s.name, i * 2 + 1);
+		symbols.emplace_back(s);
+
+	}
+
+}
+
+
+void generate_end() {
+	const std::string names[] = {
+			"_END_PAGE0",
+			"_END_CODE",
+			"_END_KDATA"
+			"_END_DATA"
+			"_END_UDATA"	
+	};
+
+	for (int i = 0; i < 5; ++i) {
+		symbol s;
+		s.section = i;
+		s.type = S_REL;
+		s.flags = SF_DEF | SF_GBL;
+		s.offset = sections[i].data.size();
+
+		symbols[i * 2 + 1] = s;
+	}
+}
+
+void merge_data() {
+
+	// merge data sections -- kdata, data, udata.
+	// merge custom data sections?
+
+	std::vector<uint8_t> new_data;
+	std::vector<expression> new_expr;
+
+	unsigned new_number = 0;
+
+	uint32_t total_data_size = 0;
+	uint32_t total_code_size = 0;
+	for (const auto &s : sections) {
+		if (s.flags & SEC_REF_ONLY) continue;
+		if (s.flags & SEC_DATA) total_data_size += s.data.size();
+		else total_code_size += s.data.size();
+	}
+
+
+	// also merge code if total size is ok...
+	uint32_t size = 0;
+	for (int i = 1; i < 5; ++i) {
+		size += sections[i].data.size();
+	}
+	if (size <= 0xffff) {
+		new_data = std::move(sections[SECT_CODE].data);
+		new_expr = std::move(sections[SECT_CODE].expressions);
+		new_number = 1;
+	}
+
+	std::vector< std::pair<unsigned, uint32_t> > remap;
+	remap.reserve(sections.size());
+
+	for (unsigned i = 0; i < sections.size(); ++i)
+		remap.emplace_back(std::make_pair(i, i));
+
+
+	uint32_t fudge_kdata = 0;
+	uint32_t fudge_data = 0;
+	uint32_t fudge_udata = 0;
+
+	section *s = &sections[SECT_KDATA];
+	fudge_kdata = new_data.size();
+
+	new_data.insert(new_data.end(), s->data.begin(), s->data.end());
+	new_expr.insert(new_expr.end(),
+		std::make_move_iterator(s->expressions.begin()),
+		std::make_move_iterator(s->expressions.end())
+	);
+	*s = section{};
+
+	s = &sections[SECT_DATA];
+	fudge_data = new_data.size();
+
+	new_data.insert(new_data.end(), s->data.begin(), s->data.end());
+	new_expr.insert(new_expr.end(),
+		std::make_move_iterator(s->expressions.begin()),
+		std::make_move_iterator(s->expressions.end())
+	);
+	*s = section{};
+
+
+	s = &sections[SECT_UDATA];
+	fudge_udata = new_data.size();
+
+	new_data.insert(new_data.end(), s->data.begin(), s->data.end());
+	new_expr.insert(new_expr.end(),
+		std::make_move_iterator(s->expressions.begin()),
+		std::make_move_iterator(s->expressions.end())
+	);
+	*s = section{};
+
+
+
+	if (size > 0xffff) {
+		// not merged into code.
+
+		new_number = sections.size();
+
+		section tmp;
+		tmp.name = "data";
+		tmp.flags = SEC_DATA;
+		tmp.data = std::move(new_data);
+		tmp.expressions = std::move(new_expr);
+		sections.emplace_back(tmp);
+	}
+
+
+	// update all symbols with the new location / offset.
+
+	for (auto &s : symbols) {
+		if ((s.type & 0x0f) == S_REL) switch(s.section) {
+			case SECT_DATA:
+				s.section = new_number;
+				s.offset += fudge_data;
+				break;
+			case SECT_KDATA:
+				s.section = new_number;
+				s.offset += fudge_kdata;
+				break;
+			case SECT_UDATA:
+				s.section = new_number;
+				s.offset += fudge_udata;
+				break;
+		}
+	}
+
+	// update expressions with new section / offset.
+	for (auto &s : sections) {
+		for (auto &e : s.expressions) {
+			bool delta = false;
+			for (auto &t : e.stack) {
+				if (t.tag == OP_LOC) {
+					switch(t.section) {
+						case SECT_DATA:
+							t.section = new_number;
+							t.value += fudge_data;
+							delta = true;
+							break;
+						case SECT_KDATA:
+							t.section = new_number;
+							t.value += fudge_kdata;
+							delta = true;
+							break;
+						case SECT_UDATA:
+							t.section = new_number;
+							t.value += fudge_udata;
+							delta = true;
+							break;
+					}
+				}
+			}
+			if (delta) simplify_expression(e);
+		}
+	}
+
+
+
+}
+
+
+bool one_file(const std::string &name) {
+
+	int fd = open(name.c_str(), O_RDONLY | O_BINARY);
+	if (fd < 0) {
+		warn("Unable to open %s", name.c_str());
+		return false;
+	}
+	bool rv = false;
+
+	Header h;
+	ssize_t ok;
+
+	ok = read(fd, &h, sizeof(h));
+	if (ok != sizeof(h)) {
+		warnx("Invalid object file: %s", name.c_str());
+		close(fd);
+		return false;
+	}
+
+	le_to_host(h.magic);
+	le_to_host(h.version);
+	le_to_host(h.filetype);
+
+	if (h.magic != MOD_MAGIC || h.version != MOD_VERSION || h.filetype < MOD_OBJECT || h.filetype > MOD_LIBRARY) {
+		warnx("Invalid object file: %s", name.c_str());
+		close(fd);
+		return false;
+	}
+
+	if (h.filetype == MOD_LIBRARY) {
+		warnx("%s is a library", name.c_str());
+		close(fd);
+		// todo -- add to library list...
+		return true;
+	}
+
+	//
+	rv = true;
+	lseek(fd, 0, SEEK_SET);
+	for(;;) {
+		Mod_head h;
+
+		ok = read(fd, &h, sizeof(h));
+		if (ok == 0) break; // eof.
+
+		rv = false;
+		if (ok < sizeof(h)) {
+			warnx("Invalid object file: %s", name.c_str());
+			break;
+		}
+
+		le_to_host(h.h_magic);
+		le_to_host(h.h_version);
+		le_to_host(h.h_filtyp);
+		le_to_host(h.h_namlen);
+		le_to_host(h.h_recsize);
+		le_to_host(h.h_secsize);
+		le_to_host(h.h_symsize);
+		le_to_host(h.h_optsize);
+		le_to_host(h.h_tot_secs);
+		le_to_host(h.h_num_secs);
+		le_to_host(h.h_num_syms);
+
+		assert(h.h_magic == MOD_MAGIC);
+		assert(h.h_version == 1);
+		assert(h.h_filtyp == 1);
+
+
+		std::string module_name;
+		{
+			// now read the name (h_namlen includes 0 terminator.)
+			std::vector<char> tmp;
+			tmp.resize(h.h_namlen);
+			ok = read(fd, tmp.data(), h.h_namlen);
+			if (ok != h.h_namlen) {
+				warnx("Invalid object file: %s", name.c_str());
+				break;
+			}
+			module_name.assign(tmp.data());
+		}
+
+		std::vector<uint8_t> record_data;
+		std::vector<uint8_t> symbol_data;
+		std::vector<uint8_t> section_data;
+
+		record_data.resize(h.h_recsize);
+		ok = read(fd, record_data.data(), h.h_recsize);
+		if (ok != h.h_recsize) {
+			warnx("Truncated object file: %s", name.c_str());
+			break;
+		}
+
+		section_data.resize(h.h_secsize);
+		ok = read(fd, section_data.data(), h.h_secsize);
+		if (ok != h.h_secsize) {
+			warnx("Truncated object file: %s", name.c_str());
+			break;
+		}
+
+		symbol_data.resize(h.h_symsize);
+		ok = read(fd, symbol_data.data(), h.h_symsize);
+		if (ok != h.h_symsize)  {
+			warnx("Truncated object file: %s", name.c_str());
+			break;
+		}
+
+		// should probably pass in name and module....
+		one_module(record_data, section_data, symbol_data);
+		rv = true;
+	}
+
+
+	close(fd);
+	return rv;
+}
 
 void help() {
 	exit(0);
@@ -48,11 +859,26 @@ int main(int argc, char **argv) {
 
 	if (argc == 0) usage();
 
+	init();
+
+	for (int i = 0 ; i < argc; ++i) {
+		one_file(argv[i]);
+	}
+
+	//
+	simplify();
+
+	// for each undefined, try to find it in a library...
+
+	for (const auto & s : undefined_symbols) {
+		printf("%s\n", s.c_str());
+	}
+
+	generate_end();
+
+	merge_data();
+
+
+
 }
 
-
-
-struct section {
-	std::vector<uint8_t> data;
-	uint32_t offset; 
-}
\ No newline at end of file