refactor elf32 assembler, add support for multiple isa's in cmdline

1 files changed, 0 insertions, 549 deletions

diff --git a/masm/asm.c b/masm/asm.c
deleted file mode 100644
index 8cbc439..0000000
--- a/masm/asm.c
+++ /dev/null
@@ -1,549 +0,0 @@
-#include <merror.h>
-#include <netinet/in.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <elf.h>
-#include <string.h>
-#include <stddef.h>
-#include <melf.h>
-
-#include "asm.h"
-#include "gen.h"
-#include "tab.h"
-
-extern char *current_file;
-
-#define SYMSEC_STUB -1
-#define SYMSEC_EXTERN -1
-
-#define SEC_ALIGN 0x1000
-
-static int elf_rel_type(enum reference_type ty) {
-	switch (ty) {
-	case REF_NONE:
-		return R_MIPS_NONE;
-	case REF_MIPS_16:
-		return R_MIPS_16;
-	case REF_MIPS_26:
-		return R_MIPS_26;
-	case REF_MIPS_PC16:
-		return R_MIPS_PC16;
-	case REF_MIPS_LO16:
-		return R_MIPS_LO16;
-	case REF_MIPS_HI16:
-		return R_MIPS_HI16;
-	}
-
-	return R_MIPS_NONE;
-}
-
-static int elf_section_init_reltab(struct section *sec,
-				   struct elf_section *elf_sec)
-{
-	Elf32_Rel *reltab = malloc(sizeof(Elf32_Rel) *
-		     sec->reftab.len);
-
-	if (reltab == NULL) {
-		PERROR("cannot alloc");
-		return M_ERROR;
-	}
-	for (uint32_t i = 0; i < sec->reftab.len; i++) {
-		Elf32_Rel *rel = &reltab[i];
-		struct reference *ref = &sec->reftab.references[i];
-		rel->r_offset = B32(ref->offset);
-		int sym = ref->symbol->tabidx + 1;
-		int type = elf_rel_type(ref->type);
-		rel->r_info = B32(ELF32_R_INFO(sym, type));
-	}
-
-	elf_sec->reltab_len = sec->reftab.len;
-	elf_sec->reltab = reltab;
-
-	return M_SUCCESS;
-}
-
-static int elf_section_init(struct section *sec, struct elf_section *elf_sec)
-{
-	elf_sec->data = sec;
-	elf_sec->shdr_idx = 0; // dont know yet
-	elf_sec->reltab_shidx = 0; // dont know yet
-	elf_sec->reltab_len = sec->reftab.len;
-	elf_sec->reltab = NULL;
-
-	if (sec->reftab.len && elf_section_init_reltab(sec, elf_sec))
-		return M_ERROR;
-
-	return M_SUCCESS;
-}
-
-/* free an elf section */
-static void elf_section_free(struct elf_section *sec)
-{
-	if (sec->reltab != NULL)
-		free(sec->reltab);
-}
-
-static int asm_init_sections(struct assembler *assembler)
-{
-	struct section *sections = assembler->gen.sections;
-	uint32_t len = assembler->gen.sections_len;
-
-	struct elf_section *elftab = malloc(sizeof(struct elf_section) * len);
-	if (elftab == NULL) {
-		PERROR("cannot alloc");
-		return M_ERROR;
-	}
-
-	for (uint32_t i = 0; i < len; i++) {
-		struct elf_section *elfsec = &elftab[i];
-		elfsec->data = &sections[i];
-		if (elf_section_init(&sections[i], elfsec)) {
-			free(elftab);
-			return M_ERROR;
-		}
-	}
-
-	assembler->sections = elftab;
-	assembler->section_len = len;
-	return M_SUCCESS;
-}
-
-static int elf_sym_bind(enum symbol_type ty) {
-	switch (ty) {
-	case SYM_LOCAL:
-		return STB_LOCAL;
-	case SYM_GLOBAL:
-		return STB_GLOBAL;
-	case SYM_EXTERN:
-		return STB_GLOBAL;
-	}
-
-	return STB_GLOBAL;
-}
-
-static int asm_init_symtab(struct assembler *assembler) {
-	struct symbol_table *symtab = &assembler->gen.symtab;
-	size_t len = symtab->len + 1;
-	Elf32_Sym *elftab = malloc(sizeof(Elf32_Sym) * len);
-	if (elftab == NULL) {
-		PERROR("cannot alloc");
-	}
-
-	// add null entry
-	elftab[0] = (Elf32_Sym) {0};
-
-	// add rest of the entries
-	for (uint32_t i = 0; i < symtab->len; i++) {
-		struct symbol *sym = &symtab->symbols[i];
-		int bind = elf_sym_bind(sym->type);
-		int type = STT_NOTYPE;
-
-		// get name
-		size_t str_off;
-		if (strtab_write_str(&assembler->strtab, sym->name.str,
-		     &str_off)) {
-			free(elftab);
-			return M_ERROR;
-		}
-
-		elftab[i+1] = (Elf32_Sym) {
-			.st_name = B32(str_off),
-			.st_info = ELF32_ST_INFO(bind, type),
-			.st_size = 0,
-			.st_other = 0,
-			.st_value = B32(sym->offset),
-			.st_shndx = 0,
-		};
-	}
-
-	assembler->symbols = elftab;
-	assembler->symtab_len = len;
-
-	return M_SUCCESS;
-}
-
-static int parse_file(struct assembler *assembler)
-{
-	if (generate_mips32r6(&assembler->gen))
-		return M_ERROR;
-	if (asm_init_sections(assembler))
-		return M_ERROR;
-	if (asm_init_symtab(assembler))
-		return M_ERROR;
-	return M_SUCCESS;
-}
-
-static int assemble_shdr(struct assembler *assembler, Elf32_Shdr **res,
-			 uint32_t *res2)
-{
-	uint32_t max_entries = 0;
-	max_entries += 1; // null
-	max_entries += 1; // symtab
-	max_entries += 1; // strtab
-	max_entries += 1; // shtrtab
-	max_entries += assembler->section_len; // sections
-	max_entries += assembler->section_len; // reltabs per section
-
-	Elf32_Shdr *shdr = malloc(sizeof(Elf32_Shdr) * max_entries);
-
-	if (shdr == NULL) {
-		PERROR("cannot alloc");
-		return M_ERROR;
-	}
-
-	size_t str_off;
-	uint32_t count = 0;
-
-	// null
-	shdr[count++] = (Elf32_Shdr) {0};
-
-	// reltables
-	for (uint32_t i = 0; i < assembler->section_len; i++) {
-		struct elf_section *sec = &assembler->sections[i];
-		const char *prefix = ".reltab";
-		char reltab_name[MAX_EXT_LENGTH + strlen(prefix)];
-
-		if (sec->reltab_len == 0)
-			continue;
-
-		strcpy(reltab_name, prefix);
-		strncat(reltab_name, sec->data->name.str,
-				MAX_EXT_LENGTH - strlen(prefix));
-
-		if (strtab_write_str(&assembler->shstrtab,
-		       reltab_name, &str_off)) {
-			free(shdr);
-			return M_ERROR;
-		}
-
-		sec->reltab_shidx = count;
-		shdr[count++] = (Elf32_Shdr) {
-			.sh_name = B32(str_off),
-			.sh_type = B32(SHT_REL),
-			.sh_flags = 0,
-			.sh_addr = 0,
-			.sh_offset = 0,
-			.sh_size = 0,
-			.sh_link = 0,
-			.sh_info = 0,
-			.sh_addralign = B32(1),
-			.sh_entsize = B32(sizeof(Elf32_Rel)),
-		};
-	}
-
-	// for each section
-	for (uint32_t i = 0; i < assembler->section_len; i++) {
-		struct elf_section *sec = &assembler->sections[i];
-		const char *name = sec->data->name.str;
-
-		if (strtab_write_str(&assembler->shstrtab, name, &str_off)) {
-			free(shdr);
-			return M_ERROR;
-		}
-
-		sec->shdr_idx = count;
-		if (sec->reltab_len != 0)
-			shdr[sec->reltab_shidx].sh_info = B32(count);
-
-		shdr[count++] = (Elf32_Shdr){
-		    .sh_name = B32(str_off),
-		    .sh_type = B32(sec->data->execute ?
-					SHT_PROGBITS : SHT_NOBITS),
-		    .sh_flags = B32(
-				(sec->data->write << 0) |
-				(sec->data->execute << 2) |
-				SHF_ALLOC),
-		    .sh_addr = 0,
-		    .sh_offset = 0,
-		    .sh_size = 0,
-		    .sh_link = 0,
-		    .sh_info = 0,
-		    .sh_addralign = B32(SEC_ALIGN),
-		    .sh_entsize = 0,
-		};
-	}
-
-	// symbol table
-	if (strtab_write_str(&assembler->shstrtab, ".symtab", &str_off)) {
-		free(shdr);
-		return M_ERROR;
-	}
-
-	assembler->symtab_shidx = count;
-	shdr[count++] = (Elf32_Shdr) {
-		.sh_name = B32(str_off),
-		.sh_type = B32(SHT_SYMTAB),
-		.sh_flags = 0,
-		.sh_addr = 0,
-		.sh_offset = 0,
-		.sh_size = 0,
-		.sh_link = 1,
-		.sh_info = 0,
-		.sh_addralign = B32(1),
-		.sh_entsize = B32(sizeof(Elf32_Sym)),
-	};
-
-	// string table
-	if (strtab_write_str(&assembler->shstrtab, ".strtab", &str_off)) {
-		free(shdr);
-		return M_ERROR;
-	}
-
-	assembler->strtab_shidx = count;
-	shdr[count++] = (Elf32_Shdr) {
-		.sh_name = B32(str_off),
-		.sh_type = B32(SHT_STRTAB),
-		.sh_flags = B32(SHF_STRINGS),
-		.sh_addr = 0,
-		.sh_offset = 0,
-		.sh_size = 0,
-		.sh_link = 0,
-		.sh_info = 0,
-		.sh_addralign = B32(1),
-		.sh_entsize = 0,
-	};
-
-	// sh string table
-	if (strtab_write_str(&assembler->shstrtab, ".shstrtab", &str_off)) {
-		free(shdr);
-		return M_ERROR;
-	}
-
-	assembler->shstrtab_shidx = count;
-	shdr[count++] = (Elf32_Shdr) {
-		.sh_name = B32(str_off),
-		.sh_type = B32(SHT_STRTAB),
-		.sh_flags = B32(SHF_STRINGS),
-		.sh_addr = 0,
-		.sh_offset = 0,
-		.sh_size = 0,
-		.sh_link = 0,
-		.sh_info = 0,
-		.sh_addralign = B32(1),
-		.sh_entsize = 0,
-	};
-
-	for (uint32_t i = 0; i < assembler->section_len; i++) {
-		struct elf_section *sec = &assembler->sections[i];
-		if (sec->reltab_len == 0)
-			continue;
-		shdr[sec->reltab_shidx].sh_link =
-			B32(assembler->symtab_shidx);
-	}
-
-	*res = shdr;
-	*res2 = count;
-
-	return M_SUCCESS;
-}
-
-static void update_offsets(struct assembler *assembler, Elf32_Ehdr *ehdr)
-{
-	Elf32_Shdr *shdr = (Elf32_Shdr *) assembler->shdr;
-	uint32_t ptr = 0;
-
-	// we must now correct offets and sizes inside the ehdr, phdr,
-	// and shdr
-	ptr += sizeof(Elf32_Ehdr);
-
-	// reltbls
-	for (uint32_t i = 0; i < assembler->section_len; i++) {
-		struct elf_section *sec = &assembler->sections[i];
-		if (sec->reltab_len == 0)
-			continue;
-		int idx = sec->reltab_shidx;
-		int len = sec->reltab_len;
-		shdr[idx].sh_offset = B32(ptr);
-		shdr[idx].sh_size = B32(len * sizeof(Elf32_Rel));
-		ptr += len * sizeof(Elf32_Rel);
-	}
-
-	// sections
-	size_t v_addr = 0;
-	for (uint32_t i = 0; i < assembler->section_len; i++) {
-
-		size_t pad = v_addr % SEC_ALIGN;
-		if (pad)
-			pad = SEC_ALIGN - pad;
-		v_addr += pad;
-
-		struct elf_section *sec = &assembler->sections[i];
-		uint32_t idx = sec->shdr_idx;
-		uint32_t size = sec->data->len;
-		shdr[idx].sh_offset = B32(ptr);
-		shdr[idx].sh_size = B32(size);
-		shdr[idx].sh_addr = B32(v_addr);
-		v_addr += size;
-		ptr += size;
-	}
-
-	// symtab
-	{
-		uint32_t len = assembler->symtab_len;
-		uint32_t size = len * sizeof(Elf32_Sym);
-		shdr[assembler->symtab_shidx].sh_offset = B32(ptr);
-		shdr[assembler->symtab_shidx].sh_link =
-			B32(assembler->strtab_shidx);
-		shdr[assembler->symtab_shidx].sh_size = B32(size);
-		ptr += size;
-	}
-
-	// strtab
-	shdr[assembler->strtab_shidx].sh_offset = B32(ptr);
-	shdr[assembler->strtab_shidx].sh_size = B32(assembler->strtab.size);
-	ptr += assembler->strtab.size;
-
-	// shstrtab
-	shdr[assembler->shstrtab_shidx].sh_offset = B32(ptr);
-	shdr[assembler->shstrtab_shidx].sh_size =
-		B32(assembler->shstrtab.size);
-	ptr += assembler->shstrtab.size;
-	// shdr
-	ehdr->e_shoff = B32(ptr);
-}
-
-static int write_file(struct assembler *assembler, Elf32_Ehdr *ehdr,
-		       const char *path)
-{
-	FILE *out = fopen(path, "w");
-
-	if (out == NULL)
-	{
-		PERROR("cannot write '%s'", path);
-		return M_ERROR;
-	}
-
-	// ehdr
-	fwrite(ehdr, sizeof(Elf32_Ehdr), 1, out);
-
-	// reltbls
-	for (uint32_t i = 0; i < assembler->section_len; i++) {
-		struct elf_section *sec = &assembler->sections[i];
-		void *ptr = sec->reltab;
-		int len = sec->reltab_len;
-		if (len < 1)
-			continue;
-		fwrite(ptr, sizeof(Elf32_Rel), len, out);
-	}
-
-	// sections
-	for (uint32_t i = 0; i < assembler->section_len; i++) {
-		struct elf_section *sec = &assembler->sections[i];
-		void *ptr = sec->data->data;
-		size_t size = sec->data->len;
-		fwrite(ptr, 1, size, out);
-	}
-
-	// sym tbl
-	fwrite(assembler->symbols, sizeof(Elf32_Sym), assembler->symtab_len,
-		out);
-
-	// str tbl
-	fwrite(assembler->strtab.ptr, 1, assembler->strtab.size, out);
-
-	// shstr tbl
-	fwrite(assembler->shstrtab.ptr, 1, assembler->shstrtab.size, out);
-
-	// shdr
-	fwrite(assembler->shdr, sizeof(Elf32_Shdr), assembler->shdr_len, out);
-
-	// close
-	fclose(out);
-
-	return M_SUCCESS;
-}
-
-static void update_sym_shndx(struct assembler *assembler)
-{
-	for (uint32_t i = 1; i < assembler->symtab_len; i++) {
-		Elf32_Sym *esym = &assembler->symbols[i];
-		struct symbol *sym = &assembler->gen.symtab.symbols[i - 1];
-
-		// get shindx
-		int shindx = 0;
-		if (sym->secidx != SYM_SEC_STUB)
-			shindx = assembler->sections[sym->secidx].shdr_idx;
-		else if (sym->type == SYM_EXTERN)
-			shindx = 0;
-
-		esym->st_shndx = B16(shindx);
-	}
-}
-
-static int assemble_elf(struct assembler *assembler, const char *out)
-{
-	if (assemble_shdr(assembler, &assembler->shdr, &assembler->shdr_len))
-		return M_ERROR;
-
-	Elf32_Ehdr ehdr = MIPS_ELF_EHDR;
-	ehdr.e_shnum = B16(assembler->shdr_len);
-	ehdr.e_shstrndx = B16(assembler->shstrtab_shidx);
-	update_offsets(assembler, &ehdr);
-	update_sym_shndx(assembler);
-
-	if (write_file(assembler, &ehdr, out))
-		return M_ERROR;
-
-	return M_SUCCESS;
-}
-
-int assemble_file(struct assembler_arguments args)
-{
-	struct assembler assembler;
-	int res = M_SUCCESS;
-
-	current_file = args.in_file;
-
-	if (assembler_init(&assembler, args.in_file))
-		return M_ERROR;
-
-	if (res == M_SUCCESS)
-		res = parse_file(&assembler);
-
-	if (res == M_SUCCESS)
-		res = assemble_elf(&assembler, args.out_file);
-
-	assembler_free(&assembler);
-
-	return res;
-}
-
-int assembler_init(struct assembler *assembler, const char *path)
-{
-	assembler->shdr = NULL;
-	assembler->symbols = NULL;
-	assembler->sections = NULL;
-	assembler->strtab.ptr = NULL;
-	assembler->shstrtab.ptr = NULL;
-	assembler->gen.sections = NULL;
-	assembler->gen.symtab.symbols = NULL;
-	assembler->section_len = 0;
-
-	if (generator_init(path, &assembler->gen))
-		return M_ERROR;
-
-	if (strtab_init(&assembler->shstrtab))
-		return M_ERROR;
-
-	if (strtab_init(&assembler->strtab))
-		return M_ERROR;
-
-	return M_SUCCESS;
-}
-
-void assembler_free(struct assembler *assembler)
-{
-	if (assembler->shdr)
-		free(assembler->shdr);
-	if (assembler->symbols)
-		free(assembler->symbols);
-	if (assembler->sections) {
-		for (uint32_t i = 0; i < assembler->section_len; i++)
-			elf_section_free(&assembler->sections[i]);
-		free(assembler->sections);
-	}
-
-	strtab_free(&assembler->strtab);
-	strtab_free(&assembler->shstrtab);
-	generator_free(&assembler->gen);
-}