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[/] [openrisc/] [tags/] [or1ksim/] [or1ksim-0.4.0/] [cpu/] [or32/] [dyngen-elf.c] - Rev 169
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/* dyngen-elf.c -- Elf parser for dyngen Copyright (C) 2005 György `nog' Jeney, nog@sdf.lonestar.org This file is part of OpenRISC 1000 Architectural Simulator. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <stdio.h> #include <stdlib.h> #include <stdint.h> #include <assert.h> #include <elf.h> #include "dyngen.h" struct elf_obj { Elf32_Ehdr e_hdr; Elf32_Shdr *e_shdrs; void **e_sections; Elf32_Sym *e_syms; /* The symbol table in the elf file */ unsigned int e_sym_num; /* The number of symbols */ unsigned int e_sym_str_tab; /* The string-table associated with symbols */ Elf32_Rel *e_rels; unsigned int e_rel_num; /* The number of relocations (in e_rel) */ unsigned int e_rel_sym; unsigned int e_rel_sec; /* The section to modify */ Elf32_Rela *e_relas; unsigned int e_rela_num; /* The number of relocations (in e_rela) */ unsigned int e_rela_sym; unsigned int e_rela_sec; /* The section to modify */ }; void *elf_open_obj(const char *file) { struct elf_obj *obj; FILE *f; int i; if(!(obj = malloc(sizeof(struct elf_obj)))) { fprintf(stderr, "OOM\n"); return NULL; } if(!(f = fopen(file, "r"))) { free(obj); return NULL; } fread(&obj->e_hdr, sizeof(Elf32_Ehdr), 1, f); /* Do some sanity checks */ if((obj->e_hdr.e_ident[EI_MAG0] != ELFMAG0) || (obj->e_hdr.e_ident[EI_MAG1] != ELFMAG1) || (obj->e_hdr.e_ident[EI_MAG2] != ELFMAG2) || (obj->e_hdr.e_ident[EI_MAG3] != ELFMAG3)) { fprintf(stderr, "%s is not an elf file!\n", file); goto error_load; } if(obj->e_hdr.e_ident[EI_CLASS] == ELFCLASSNONE) { fprintf(stderr, "Invalid class in ELF header\n"); goto error_load; } if(obj->e_hdr.e_ident[EI_DATA] == ELFDATANONE) { fprintf(stderr, "Invalid data format in ELF header\n"); goto error_load; } /* FIXME: Swap data as necessary */ if((obj->e_hdr.e_ident[EI_VERSION] != 1) || (obj->e_hdr.e_version != 1)) { fprintf(stderr, "Unexpected elf version found: %i (%li)\n", obj->e_hdr.e_ident[EI_VERSION], (long int)obj->e_hdr.e_version); goto error_load; } if(obj->e_hdr.e_type != ET_REL) { fprintf(stderr, "Appears that we did not receive a object file\n"); goto error_load; } if(obj->e_hdr.e_phoff) { fprintf(stderr, "What am I supposed to do with a program header??\n"); goto error_load; } if(obj->e_hdr.e_ehsize != sizeof(Elf32_Ehdr)) { fprintf(stderr, "Unknown size of elf header\n"); goto error_load; } if(!obj->e_hdr.e_shoff || !obj->e_hdr.e_shnum) { fprintf(stderr, "The elf file contains no sections!\n"); goto error_load; } if(obj->e_hdr.e_shentsize != sizeof(Elf32_Shdr)) { fprintf(stderr, "Unknown section header size %i\n", obj->e_hdr.e_shentsize); goto error_load; } /* Load the section headers */ if(!(obj->e_shdrs = malloc(obj->e_hdr.e_shentsize * obj->e_hdr.e_shnum))){ fprintf(stderr, "OOM\n"); goto error_load; } fseek(f, obj->e_hdr.e_shoff, SEEK_SET); fread(obj->e_shdrs, obj->e_hdr.e_shentsize, obj->e_hdr.e_shnum, f); /* FIXME: swap data */ /* Load the sections */ if(!(obj->e_sections = calloc(obj->e_hdr.e_shnum, sizeof(void *)))) { fprintf(stderr, "OOM\n"); free(obj->e_shdrs); goto error_load; } for(i = 0; i < obj->e_hdr.e_shnum; i++) { if(obj->e_shdrs[i].sh_type == SHT_NOBITS) continue; if(!(obj->e_sections[i] = malloc(obj->e_shdrs[i].sh_size))) { fprintf(stderr, "OOM\n"); goto post_sec_error_load; } fseek(f, obj->e_shdrs[i].sh_offset, SEEK_SET); fread(obj->e_sections[i], obj->e_shdrs[i].sh_size, 1, f); } obj->e_rels = NULL; obj->e_syms = NULL; obj->e_relas = NULL; /* Find the symbol table and relocation table(s) */ for(i = 0; i < obj->e_hdr.e_shnum; i++) { switch(obj->e_shdrs[i].sh_type) { case SHT_SYMTAB: if(obj->e_syms) { fprintf(stderr, "ELF file has more than one symbol table\n"); goto post_sec_error_load; } if(obj->e_shdrs[i].sh_entsize != sizeof(Elf32_Sym)) { fprintf(stderr, "ELF symbol table entry size is unknown\n"); goto post_sec_error_load; } if((obj->e_shdrs[i].sh_size % obj->e_shdrs[i].sh_entsize)) { fprintf(stderr, "Symbol table's length is not a multiple of sizeof(Elf32_Sym\n"); goto post_sec_error_load; } obj->e_syms = obj->e_sections[i]; obj->e_sym_num = obj->e_shdrs[i].sh_size / obj->e_shdrs[i].sh_entsize; obj->e_sym_str_tab = obj->e_shdrs[i].sh_link; break; case SHT_REL: if(obj->e_rels) { fprintf(stderr, "ELF file has more than one relocation table\n"); goto post_sec_error_load; } if(obj->e_shdrs[i].sh_entsize != sizeof(Elf32_Rel)) { fprintf(stderr, "ELF relocation table entry size is unknown\n"); goto post_sec_error_load; } if((obj->e_shdrs[i].sh_size % obj->e_shdrs[i].sh_entsize)) { fprintf(stderr, "Relocation table's length is not a multiple of sizeof(Elf32_Rel\n"); goto post_sec_error_load; } obj->e_rels = obj->e_sections[i]; obj->e_rel_sec = obj->e_shdrs[i].sh_info; obj->e_rel_sym = obj->e_shdrs[i].sh_link; obj->e_rel_num = obj->e_shdrs[i].sh_size / obj->e_shdrs[i].sh_entsize; break; case SHT_RELA: if(obj->e_relas) { fprintf(stderr, "ELF file has more than one a-relocation table\n"); goto post_sec_error_load; } if(obj->e_shdrs[i].sh_entsize != sizeof(Elf32_Rela)) { fprintf(stderr, "ELF a-relocation table entry size is unknown\n"); goto post_sec_error_load; } if((obj->e_shdrs[i].sh_size % obj->e_shdrs[i].sh_entsize)) { fprintf(stderr, "Relocation table's length is not a multiple of sizeof(Elf32_Rela)\n"); goto post_sec_error_load; } obj->e_relas = obj->e_sections[i]; obj->e_rela_sec = obj->e_shdrs[i].sh_info; obj->e_rela_sym = obj->e_shdrs[i].sh_link; obj->e_rela_num = obj->e_shdrs[i].sh_size / obj->e_shdrs[i].sh_entsize; break; } } fclose(f); return obj; post_sec_error_load: for(i = 0; i < obj->e_hdr.e_shnum; i++) { if(obj->e_sections[i]) free(obj->e_sections[i]); } free(obj->e_sections); free(obj->e_shdrs); error_load: free(obj); fclose(f); return NULL; } void elf_close_obj(void *e_obj) { struct elf_obj *obj = e_obj; int i; for(i = 0; i < obj->e_hdr.e_shnum; i++) { if(obj->e_sections[i]) free(obj->e_sections[i]); } free(obj->e_sections); free(obj->e_shdrs); free(obj); } static Elf32_Sym *elf_find_func(struct elf_obj *obj, unsigned int func) { int i, j; Elf32_Sym *cur; for(i = 0, j = 0, cur = obj->e_syms; i < obj->e_sym_num; i++, cur++) { if(ELF32_ST_BIND(cur->st_info) != STB_GLOBAL) continue; if(ELF32_ST_TYPE(cur->st_info) != STT_FUNC) continue; if(j == func) return cur; j++; } return NULL; } char *elf_get_func_name(void *e_obj, unsigned int func) { struct elf_obj *obj = e_obj; Elf32_Sym *func_sym = elf_find_func(obj, func); if(func_sym) return obj->e_sections[obj->e_sym_str_tab] + func_sym->st_name; return NULL; } unsigned int elf_get_func_len(void *e_obj, unsigned int func) { struct elf_obj *obj = e_obj; Elf32_Sym *func_sym = elf_find_func(obj, func); if(func_sym) return func_sym->st_size; return 0; } void *elf_get_func_start(void *e_obj, unsigned int func) { struct elf_obj *obj = e_obj; Elf32_Sym *func_sym = elf_find_func(obj, func); if(!func_sym) return NULL; if(func_sym->st_shndx == SHN_COMMON) { fprintf(stderr, "Don't know how to handle SHN_COMMON section header\n"); return NULL; } return obj->e_sections[func_sym->st_shndx] + func_sym->st_value; } static char *elf_get_sym_name(struct elf_obj *obj, unsigned int sym) { char *name; name = obj->e_sections[obj->e_sym_str_tab]; name += obj->e_syms[sym].st_name; return name; } int elf_get_func_reloc(void *e_obj, unsigned int func, unsigned int relocn, struct reloc *reloc) { struct elf_obj *obj = e_obj; Elf32_Sym *func_sym = elf_find_func(obj, func); Elf32_Rel *cur; Elf32_Rela *cura; int i, j; /* if(obj->e_rel_sec != func_sym->st_shndx) { fprintf(stderr, "Don't know what to do: Function does not have a relocation table\n"); return 0; } */ for(i = 0, j = 0, cur = obj->e_rels; i < obj->e_rel_num; i++, cur++) { if((cur->r_offset - func_sym->st_value) > func_sym->st_size) continue; if(relocn == j) { reloc->name = elf_get_sym_name(obj, ELF32_R_SYM(cur->r_info)); reloc->func_offset = cur->r_offset - func_sym->st_value; reloc->type = ELF32_R_TYPE(cur->r_info); /* FIXME: Byte-swap */ reloc->addend = *(uint32_t *)(obj->e_sections[obj->e_rel_sec] + cur->r_offset); return 1; } j++; } if(!obj->e_relas) return 0; for(i = 0, cura = obj->e_relas; i < obj->e_rela_num; i++, cura++) { if((cura->r_offset - func_sym->st_value) > func_sym->st_size) continue; if(relocn == j) { reloc->name = elf_get_sym_name(obj, ELF32_R_SYM(cur->r_info)); reloc->func_offset = cura->r_offset - func_sym->st_value; reloc->type = ELF32_R_TYPE(cur->r_info); reloc->addend = cura->r_addend; return 1; } j++; } return 0; } const struct bff bffs = { elf_open_obj, elf_close_obj, elf_get_func_name, elf_get_func_start, elf_get_func_len, elf_get_func_reloc };
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