1 files changed, 151 insertions, 0 deletions
diff --git a/mld/link.h b/mld/link.h
new file mode 100644
index 0000000..ac97bbf
--- /dev/null
+++ b/mld/link.h
@@ -0,0 +1,151 @@
+/* Copyright (c) 2024 Freya Murphy */
+
+#ifndef __LINK_H__
+#define __LINK_H__
+
+#include <linux/limits.h>
+#include <mlimits.h>
+#include <mips.h>
+#include <merror.h>
+#include <stdint.h>
+#include <elf.h>
+#include <stdio.h>
+
+
+// when mapping porinters, we need to bounds check to
+// make sure its in the mapped object file
+//
+// this checks that
+// 1. the end is in the file
+// 2. the off and len doesnt integer overflow
+#define BOUND_CHK(obj, len, off) \
+	(off > UINT32_MAX - len || off + len > obj->mapped_size)
+
+
+// pre define
+struct linker;
+struct object;
+struct segment;
+
+///
+/// relocation table
+///
+
+struct relocation_table {
+	uint32_t type;
+	union {
+		void *raw;
+		Elf32_Rel  *rel;
+		Elf32_Rela *rela;
+	};
+	size_t len;
+	struct symbol_table *symtab;
+};
+
+///
+/// string table
+///
+
+struct string_table {
+	char *data;
+	size_t len;
+};
+
+///
+/// symbol table
+///
+
+struct symbol_table {
+	struct string_table *strtab;
+	Elf32_Sym *syms;
+	size_t len;
+};
+
+///
+/// segment
+///
+
+/* a loadable program segment */
+struct segment {
+	// phdr
+	Elf32_Phdr *phdr;
+	uint32_t phdr_idx;
+
+	// shdr
+	Elf32_Shdr *shdr;
+	uint32_t shdr_idx;
+
+	// segment data
+	char *name;
+	unsigned char *bytes;
+
+	// relocation table
+	struct relocation_table reltab;
+};
+
+int segment_load(struct object *object, struct segment *segment, size_t index);
+
+///
+/// object file
+///
+
+struct object {
+	// file
+	int fd;
+	char *mapped;
+	size_t mapped_size;
+
+	// ehdr
+	Elf32_Ehdr *ehdr;
+
+	// section header table
+	Elf32_Shdr *shdr;
+	size_t shdr_len;
+
+	// program table
+	Elf32_Phdr *phdr;
+	size_t phdr_len;
+
+	// object meta
+	const char *name;
+	size_t index;
+
+	// segments
+	size_t segment_len;
+	struct segment *segments;
+
+	// section header strtab
+	struct string_table *shstrtab;
+
+	// strtabs
+	struct string_table *strtabs;
+	// symtabs
+	struct symbol_table *symtabs;
+};
+
+int object_load(struct object *object, char *path);
+
+void object_free(struct object *object);
+
+///
+/// linker
+///
+
+struct linker {
+	size_t obj_len;
+	struct object *objects;
+
+	struct linker_arguments *args;
+};
+
+/* defines arguments to the linker */
+struct linker_arguments {
+	char **in_files;
+	int in_count;
+	char *out_file;
+};
+
+/* link object files */
+int link_files(struct linker_arguments args);
+
+#endif /* __LINK_H__ */