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-rw-r--r--masm/:363
1 files changed, 363 insertions, 0 deletions
diff --git a/masm/: b/masm/:
new file mode 100644
index 0000000..96d212f
--- /dev/null
+++ b/masm/:
@@ -0,0 +1,363 @@
+#include <merror.h>
+#include <mips.h>
+#include <mips32.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <elf.h>
+#include <string.h>
+#include <stddef.h>
+
+#include "asm.h"
+#include "mlimits.h"
+#include "parse.h"
+#include "parse_mips32.h"
+
+extern char *current_file;
+
+#define SHDR_STRTBL 0
+#define SHDR_SYMTBL 1
+#define SHDR_SECTIONS 2
+
+static int parse_file(struct parser *parser)
+{
+ while (1) {
+ struct expr expr;
+ if (parser_next(parser, &expr)) {
+ break;
+ }
+
+ if (expr.type == EXPR_INS)
+ if (sectbl_push(&parser->sec_tbl,
+ parser->sec_tbl.current, expr.ins))
+ return M_ERROR;
+ }
+
+ for (uint32_t i = 0; i < parser->ref_tbl.count; i++) {
+ struct reference *ref = &parser->ref_tbl.references[i];
+ struct symbol *sym;
+ struct mips32_instruction *ins;
+
+ if (symtbl_find(&parser->sym_tbl, &sym, ref->name)) {
+ ERROR("undefined symbol '%s'", ref->name);
+ return M_ERROR;
+ }
+
+ ins = &ref->section->ins[ref->index].mips32;
+
+ switch (ref->type) {
+ case REF_OFFESET:
+ ins->B_data.offset += sym->position -
+ (ref->section->start + ref->index);
+ break;
+ case REF_TARGET:
+ ins->J_data.target += sym->position;
+ break;
+ }
+ };
+
+ return M_SUCCESS;
+}
+
+static int assemble_phdr(struct assembler *asm, Elf32_Phdr **res,
+ uint32_t *res2)
+{
+ struct parser *parser = asm->parser;
+ Elf32_Phdr *phdr = malloc(sizeof(Elf32_Phdr) *
+ parser->sec_tbl.count);
+ size_t ins_sz = sizeof(struct mips32_instruction);
+
+ if (phdr == NULL) {
+ ERROR("cannot alloc");
+ return M_ERROR;;
+ }
+
+ for (uint32_t i = 0; i < parser->sec_tbl.count; i++) {
+ Elf32_Phdr *hdr = &phdr[i];
+ struct section *sec = &parser->sec_tbl.sections[i];
+
+ hdr->p_type = PT_LOAD;
+ hdr->p_flags = PF_X | PF_W | PF_R; // FIXME: this is bad
+ hdr->p_offset = sec->start * ins_sz;
+ hdr->p_vaddr = sec->start * ins_sz;
+ hdr->p_paddr = 0x00;
+ hdr->p_filesz = sec->count * ins_sz;
+ hdr->p_memsz = sec->count * ins_sz;
+ hdr->p_align = sec->alignment;
+ }
+
+ *res = phdr;
+ *res2 = parser->sec_tbl.count;
+ return M_SUCCESS;
+}
+
+static int assemble_symtbl(struct assembler *asm, Elf32_Sym **res,
+ uint32_t *res2)
+{
+ Elf32_Sym *stbl = malloc(sizeof(Elf32_Sym) * asm->parser->sym_tbl
+ .count);
+
+ if (stbl == NULL)
+ return M_ERROR;
+
+ for (uint32_t i = 0; i < asm->parser->sym_tbl.count; i++) {
+ struct symbol *sym = &asm->parser->sym_tbl.symbols[i];
+ size_t str_off;
+
+ if (strtbl_write_str(&asm->str_tbl, sym->name, &str_off)) {
+ free(stbl);
+ return M_ERROR;
+ }
+
+ int viz = STB_LOCAL;
+ switch (sym->flag) {
+ case SYM_LOCAL:
+ viz = STB_LOCAL;
+ break;
+ case SYM_GLOBAL:
+ case SYM_EXTERNAL:
+ viz = STB_GLOBAL;
+ break;
+ }
+
+ stbl[i] = (Elf32_Sym) {
+ .st_name = str_off,
+ .st_value = sym->position,
+ .st_size = 0,
+ .st_info = (unsigned char)
+ ELF32_ST_INFO(SYMINFO_BT_SELF,
+ SYMINFO_FLG_DIRECT),
+ .st_other = (unsigned char)
+ ELF32_ST_VISIBILITY(viz),
+ .st_shndx = 0, // FIXME: specify section
+ };
+ };
+
+ *res = stbl;
+ *res2 = asm->parser->sym_tbl.count;
+
+ return M_SUCCESS;
+}
+
+static int assemble_shdr(struct assembler *asm, Elf32_Shdr **res,
+ uint32_t *res2)
+{
+ uint32_t entries = 2; // str table and sym tabel
+ entries += asm->parser->sec_tbl.count; // sections
+
+ Elf32_Shdr *shdr = malloc(sizeof(Elf32_Shdr) * entries);
+
+ size_t str_off;
+ if (strtbl_write_str(&asm->str_tbl, ".shstrtab", &str_off)) {
+ free(shdr);
+ return M_ERROR;
+ }
+
+ // string table
+ shdr[SHDR_STRTBL] = (Elf32_Shdr) {
+ .sh_name = str_off,
+ .sh_type = SHT_STRTAB,
+ .sh_flags = SHF_STRINGS,
+ .sh_addr = 0,
+ .sh_offset = 0,
+ .sh_size = 0,
+ .sh_link = 0,
+ .sh_info = 0,
+ .sh_addralign = 1,
+ .sh_entsize = 0,
+ };
+
+ if (strtbl_write_str(&asm->str_tbl, ".shsymtab", &str_off)) {
+ free(shdr);
+ return M_ERROR;
+ }
+
+ // symbol table
+ shdr[SHDR_SYMTBL] = (Elf32_Shdr) {
+ .sh_name = str_off,
+ .sh_type = SHT_SYMTAB,
+ .sh_flags = 0,
+ .sh_addr = 0,
+ .sh_offset = 0,
+ .sh_size = 0,
+ .sh_link = 0,
+ .sh_info = 0,
+ .sh_addralign = 1,
+ .sh_entsize = sizeof(Elf32_Sym),
+ };
+
+ // for each section
+ for (uint32_t i = 0; i < asm->parser->sec_tbl.count; i++) {
+ struct section *sec = &asm->parser->sec_tbl.sections[i];
+ char name[MAX_LEX_LENGTH+1] = ".";
+ strcat(name, sec->name);
+ if (strtbl_write_str(&asm->str_tbl, name, &str_off)) {
+ free(shdr);
+ return M_ERROR;
+ }
+ shdr[i+SHDR_SECTIONS] = (Elf32_Shdr) {
+ .sh_name = str_off,
+ .sh_type = SHT_PROGBITS,
+ .sh_flags = SHF_WRITE | SHF_ALLOC | SHF_EXECINSTR,
+ .sh_addr = 0,
+ .sh_offset = 0,
+ .sh_size = 0,
+ .sh_link = 0,
+ .sh_info = 0,
+ .sh_addralign = sec->alignment,
+ .sh_entsize = sizeof(struct mips32_instruction),
+ };
+ }
+
+ *res = shdr;
+ *res2 = entries;
+
+ return M_SUCCESS;
+}
+
+static int assemble_file(struct assembler *asm)
+{
+ Elf32_Phdr *phdr;
+ Elf32_Shdr *shdr;
+ Elf32_Sym *symtbl;
+ uint32_t phdr_len;
+ uint32_t shdr_len;
+ uint32_t symtbl_len;
+
+ if (assemble_symtbl(asm, &symtbl, &symtbl_len))
+ return M_ERROR;
+
+ if (assemble_phdr(asm, &phdr, &phdr_len)) {
+ free(symtbl);
+ return M_ERROR;
+ }
+
+ if (assemble_shdr(asm, &shdr, &shdr_len)) {
+ free(symtbl);
+ free(phdr);
+ return M_ERROR;
+ };
+
+ Elf32_Ehdr ehdr = {
+ .e_ident = {
+ [EI_MAG0] = ELFMAG0,
+ [EI_MAG1] = ELFMAG1,
+ [EI_MAG2] = ELFMAG2,
+ [EI_MAG3] = ELFMAG3,
+ [EI_CLASS] = ELFCLASS32,
+ [EI_DATA] = ELFDATA2LSB,
+ [EI_VERSION] = EV_CURRENT,
+ [EI_OSABI] = ELFOSABI_STANDALONE,
+ [EI_ABIVERSION] = 0x00,
+ [EI_PAD] = 0x00,
+ },
+ .e_type = ET_REL,
+ .e_machine = EM_MIPS,
+ .e_version = EV_CURRENT,
+ .e_entry = 0x00,
+ .e_phoff = 0x00,
+ .e_shoff = 0x00,
+ .e_flags = EF_MIPS_ARCH_32R6,
+ .e_ehsize = sizeof(Elf32_Ehdr),
+ .e_phentsize = 0x20,
+ .e_phnum = phdr_len,
+ .e_shentsize = 0x28,
+ .e_shnum = shdr_len,
+ .e_shstrndx = 0x00, // str table is always inx 0
+ };
+
+ uint32_t ptr = 0;
+
+ // we must now correct offets and sizes inside the ehdr, phdr,
+ // and shdr
+
+ ptr += sizeof(Elf32_Ehdr);
+
+ // phdr
+ ehdr.e_phoff = ptr;
+ ptr += phdr_len * sizeof(Elf32_Phdr);
+
+ // sections
+ for (uint32_t i = 0; i < asm->parser->sec_tbl.count; i++) {
+ phdr[i].p_offset = ptr;
+ phdr[i].p_vaddr = ptr;
+ shdr[i+SHDR_SECTIONS].sh_offset = ptr;
+ shdr[i+SHDR_SECTIONS].sh_size = phdr[i].p_filesz;
+ ptr += phdr[i].p_filesz;
+ }
+
+ // strtbl
+ shdr[SHDR_STRTBL].sh_offset = ptr;
+ shdr[SHDR_STRTBL].sh_size = asm->str_tbl.size;
+ ptr += asm->str_tbl.size;
+
+ // symtbl
+ ehdr.e_shoff = ptr;
+ shdr[SHDR_SYMTBL].sh_offset = ptr;
+ shdr[SHDR_SYMTBL].sh_size = symtbl_len * sizeof(Elf32_Sym);
+ ptr += symtbl_len * sizeof(Elf32_Sym);
+
+ FILE *out = fopen("/home/freya/out.o", "w");
+
+ // ehdr
+ fwrite(&ehdr, sizeof(Elf32_Ehdr), 1, out);
+
+ // phdr
+ fwrite(phdr, sizeof(Elf32_Phdr), phdr_len, out);
+
+ // sections
+ for (uint32_t i = 0; i < asm->parser->sec_tbl.count; i++) {
+ struct section *sec = &asm->parser->sec_tbl.sections[i];
+ for (uint32_t j = 0; j < sec->count; j++) {
+ struct mips32_instruction *ins = &sec->ins[j].mips32;
+ fwrite(ins, sizeof(struct mips32_instruction),
+ 1, out);
+ }
+ }
+
+ // str tbl
+ fwrite(asm->str_tbl.ptr, asm->str_tbl.size, 1, out);
+
+ // sym tbl
+ fwrite(symtbl, sizeof(Elf32_Sym), symtbl_len, out);
+
+ // shdr
+ fwrite(shdr, sizeof(Elf32_Shdr), shdr_len, out);
+
+ fclose(out);
+
+ free(shdr);
+ free(phdr);
+ free(symtbl);
+
+ return M_SUCCESS;
+}
+
+int assemble_file_mips32(char *path)
+{
+ struct lexer lexer;
+ struct parser parser;
+ current_file = path;
+ int res = M_SUCCESS;
+
+ if (lexer_init(current_file, &lexer))
+ return M_ERROR;
+
+ if (mips32_parser_init(&lexer, &parser))
+ return M_ERROR;
+
+ if (res == M_SUCCESS)
+ res = parse_file(&parser);
+
+ struct assembler assembler;
+ assembler.parser = &parser;
+ strtbl_init(&assembler.str_tbl);
+
+ if (res == M_SUCCESS)
+ res = assemble_file(&assembler);
+
+ strtbl_free(&assembler.str_tbl);
+ lexer_free(&lexer);
+ parser_free(&parser);
+
+ return res;
+}
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