/*-
 * Copyright (c) 2003 Jake Burkholder.
 * Copyright 1996-1998 John D. Polstra.
 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
 * Copyright (c) 1998 Peter Wemm <peter@freebsd.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD: src/sys/boot/common/reloc_elf.c,v 1.2 2005/12/18 04:52:35 marcel Exp $
 */

#include <sys/types.h>
#include <machine/elf.h>
#include <errno.h>
#include <stand.h>
#include <link.h>

#include "bootstrap.h"

#define COPYOUT(s,d,l)  archsw.arch_copyout((vm_offset_t)(s), d, l)

/*
 * Apply a single intra-module relocation to the data. `relbase' is the
 * target relocation base for the section (i.e. it corresponds to where
 * r_offset == 0). `dataaddr' is the relocated address corresponding to
 * the start of the data, and `len' is the number of bytes.
 */
int
__elfN(reloc)(struct elf_file *ef, symaddr_fn *symaddr, const void *reldata,
    int reltype, Elf_Addr relbase, Elf_Addr dataaddr, void *data, size_t len)
{
#if (defined(__x86_64__) || defined(__i386__)) && __ELF_WORD_SIZE == 64
        Elf64_Addr *where, val;
        Elf_Addr addend, addr;
        Elf_Size rtype, symidx;
        const Elf_Rel *rel;
        const Elf_Rela *rela;

        switch (reltype) {
        case ELF_RELOC_REL:
                rel = (const Elf_Rel *)reldata;
                where = (Elf64_Addr *)((char *)data + relbase + rel->r_offset -
                    dataaddr);
                addend = 0;
                rtype = ELF_R_TYPE(rel->r_info);
                symidx = ELF_R_SYM(rel->r_info);
                addend = 0;
                break;
        case ELF_RELOC_RELA:
                rela = (const Elf_Rela *)reldata;
                where = (Elf64_Addr *)((char *)data + relbase + rela->r_offset -
                    dataaddr);
                addend = rela->r_addend;
                rtype = ELF_R_TYPE(rela->r_info);
                symidx = ELF_R_SYM(rela->r_info);
                break;
        default:
                return (EINVAL);
        }

        if ((char *)where < (char *)data || (char *)where >= (char *)data + len)
                return (0);

        if (reltype == ELF_RELOC_REL)
                addend = *where;

/* XXX, definitions not available on i386. */
#define R_X86_64_64             1
#define R_X86_64_RELATIVE       8

        switch (rtype) {
        case R_X86_64_64:               /* S + A */
                addr = symaddr(ef, symidx);
                if (addr == 0)
                        return (ESRCH);
                val = addr + addend;
                *where = val;
                break;
        case R_X86_64_RELATIVE:
                addr = (Elf_Addr)addend + relbase;
                val = addr;
                *where = val;
                break;
        default:
                printf("\nunhandled relocation type %u\n", (u_int)rtype);
                return (EFTYPE);
        }

        return (0);
#elif defined(__i386__) && __ELF_WORD_SIZE == 32
        Elf_Addr addend, addr, *where, val;
        Elf_Size rtype, symidx;
        const Elf_Rel *rel;
        const Elf_Rela *rela;

        switch (reltype) {
        case ELF_RELOC_REL:
                rel = (const Elf_Rel *)reldata;
                where = (Elf_Addr *)((char *)data + relbase + rel->r_offset -
                    dataaddr);
                addend = 0;
                rtype = ELF_R_TYPE(rel->r_info);
                symidx = ELF_R_SYM(rel->r_info);
                addend = 0;
                break;
        case ELF_RELOC_RELA:
                rela = (const Elf_Rela *)reldata;
                where = (Elf_Addr *)((char *)data + relbase + rela->r_offset -
                    dataaddr);
                addend = rela->r_addend;
                rtype = ELF_R_TYPE(rela->r_info);
                symidx = ELF_R_SYM(rela->r_info);
                break;
        default:
                return (EINVAL);
        }

        if ((char *)where < (char *)data || (char *)where >= (char *)data + len)
                return (0);

        if (reltype == ELF_RELOC_REL)
                addend = *where;

/* XXX, definitions not available on x86_64. */
#define R_386_32        1       /* Add symbol value. */
#define R_386_GLOB_DAT  6       /* Set GOT entry to data address. */
#define R_386_RELATIVE  8       /* Add load address of shared object. */

        switch (rtype) {
        case R_386_RELATIVE:
                addr = addend + relbase;
                *where = addr;
                break;
        case R_386_32:          /* S + A */
                addr = symaddr(ef, symidx);
                if (addr == 0)
                        return (ESRCH);
                val = addr + addend;
                *where = val;
                break;
        default:
                printf("\nunhandled relocation type %u\n", (u_int)rtype);
                return (EFTYPE);
        }

        return (0);
#else
        return (EOPNOTSUPP);
#endif
}