arch_elf.c

newos is new operation system

/*
** Copyright 2002, Travis Geiselbrecht. All rights reserved.
** Distributed under the terms of the NewOS License.
*/
#include <kernel/kernel.h>
#include <kernel/debug.h>
#include <kernel/elf.h>
#include <newos/elf32.h>
#include <kernel/arch/elf.h>

int arch_elf_relocate_rel(struct elf_image_info *image, const char *sym_prepend,
	struct elf_image_info *resolve_image, struct Elf32_Rel *rel, int rel_len)
{
	int i;
	struct Elf32_Sym *sym;
	int vlErr;
	addr_t S;
	addr_t A;
	addr_t P;
	addr_t final_val;

	S = A = P = 0;

	for(i = 0; i * (int)sizeof(struct Elf32_Rel) < rel_len; i++) {
		//dprintf("looking at rel type %d, offset 0x%x\n", ELF32_R_TYPE(rel[i].r_info), rel[i].r_offset);

		// calc S
		switch(ELF32_R_TYPE(rel[i].r_info)) {
			case R_386_32:
			case R_386_PC32:
			case R_386_GLOB_DAT:
			case R_386_JMP_SLOT:
			case R_386_GOTOFF:
				sym = SYMBOL(image, ELF32_R_SYM(rel[i].r_info));

				vlErr = elf_resolve_symbol(image, sym, resolve_image, sym_prepend, &S);
                                if(vlErr<0) return vlErr;
				//dprintf("S 0x%x\n", S);
		}
		// calc A
		switch(ELF32_R_TYPE(rel[i].r_info)) {
			case R_386_32:
			case R_386_PC32:
			case R_386_GOT32:
			case R_386_PLT32:
			case R_386_RELATIVE:
			case R_386_GOTOFF:
			case R_386_GOTPC:
				A = *(addr_t *)(image->regions[0].delta + rel[i].r_offset);
//					dprintf("A 0x%x\n", A);
				break;
		}
		// calc P
		switch(ELF32_R_TYPE(rel[i].r_info)) {
			case R_386_PC32:
			case R_386_GOT32:
			case R_386_PLT32:
			case R_386_GOTPC:
				P = image->regions[0].delta + rel[i].r_offset;
//					dprintf("P 0x%x\n", P);
				break;
		}

		switch(ELF32_R_TYPE(rel[i].r_info)) {
			case R_386_NONE:
				continue;
			case R_386_32:
				final_val = S + A;
				break;
			case R_386_PC32:
				final_val = S + A - P;
				break;
			case R_386_RELATIVE:
				// B + A;
				final_val = image->regions[0].delta + A;
				break;
			case R_386_JMP_SLOT:
				final_val = S;
				//dprintf( "final = %lx\n", final_val );
				break;
			default:
				dprintf("arch_elf_relocate_rel: unhandled relocation type %d\n", ELF32_R_TYPE(rel[i].r_info));
				return ERR_NOT_ALLOWED;
		}
		*(addr_t *)(image->regions[0].delta + rel[i].r_offset) = final_val;
	}

	return NO_ERROR;
}

int arch_elf_relocate_rela(struct elf_image_info *image, const char *sym_prepend,
	struct elf_image_info *resolve_image, struct Elf32_Rela *rel, int rel_len)
{
	dprintf("arch_elf_relocate_rela: not supported on x86\n");
	return ERR_NOT_IMPLEMENTED;
}