freebsd-dev/sys/boot/i386/efi/reloc.c
2012-12-07 07:02:39 +00:00

108 lines
3.1 KiB
C

/*-
* Copyright (c) 2008-2010 Rui Paulo <rpaulo@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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <elf.h>
#include <efi.h>
#include <bootstrap.h>
#ifdef __i386__
#define ElfW_Rel Elf32_Rel
#define ElfW_Dyn Elf32_Dyn
#define ELFW_R_TYPE ELF32_R_TYPE
#elif __amd64__
#define ElfW_Rel Elf64_Rel
#define ElfW_Dyn Elf64_Dyn
#define ELFW_R_TYPE ELF64_R_TYPE
#endif
/*
* A simple relocator for IA32/AMD64 EFI binaries.
*/
EFI_STATUS
_reloc(unsigned long ImageBase, ElfW_Dyn *dynamic, EFI_HANDLE image_handle,
EFI_SYSTEM_TABLE *system_table)
{
unsigned long relsz, relent;
unsigned long *newaddr;
ElfW_Rel *rel;
ElfW_Dyn *dynp;
/*
* Find the relocation address, its size and the relocation entry.
*/
relsz = 0;
relent = 0;
for (dynp = dynamic; dynp->d_tag != DT_NULL; dynp++) {
switch (dynp->d_tag) {
case DT_RELA:
case DT_REL:
rel = (ElfW_Rel *) ((unsigned long) dynp->d_un.d_ptr +
ImageBase);
break;
case DT_RELSZ:
case DT_RELASZ:
relsz = dynp->d_un.d_val;
break;
case DT_RELENT:
case DT_RELAENT:
relent = dynp->d_un.d_val;
break;
default:
break;
}
}
/*
* Perform the actual relocation.
* XXX: We are reusing code for the amd64 version of this, but
* we must make sure the relocation types are the same.
*/
CTASSERT(R_386_NONE == R_X86_64_NONE);
CTASSERT(R_386_RELATIVE == R_X86_64_RELATIVE);
for (; relsz > 0; relsz -= relent) {
switch (ELFW_R_TYPE(rel->r_info)) {
case R_386_NONE:
/* No relocation needs be performed. */
break;
case R_386_RELATIVE:
/* Address relative to the base address. */
newaddr = (unsigned long *)(ImageBase + rel->r_offset);
*newaddr += ImageBase;
break;
default:
/* XXX: do we need other relocations ? */
break;
}
rel = (ElfW_Rel *) ((caddr_t) rel + relent);
}
return (EFI_SUCCESS);
}