nuttx/libs/libc/machine/x86/arch_elf.c

150 lines
5.2 KiB
C

/****************************************************************************
* machine/x86/src/up_elf.c
*
* Copyright (C) 2012, 2014, 2016-2017 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
* COPYRIGHT OWNER 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdlib.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/elf.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define R_386_32 1
#define R_386_PC32 2
#define ELF_BITS 32
#define ELF_ARCH EM_386
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: up_checkarch
*
* Description:
* Given the ELF header in 'hdr', verify that the ELF file is appropriate
* for the current, configured architecture. Every architecture that uses
* the ELF loader must provide this function.
*
* Input Parameters:
* hdr - The ELF header read from the ELF file.
*
* Returned Value:
* True if the architecture supports this ELF file.
*
****************************************************************************/
bool up_checkarch(FAR const Elf32_Ehdr *hdr)
{
return hdr->e_machine == EM_386 || hdr->e_machine == EM_486;
}
/****************************************************************************
* Name: up_relocate and up_relocateadd
*
* Description:
* Perform on architecture-specific ELF relocation. Every architecture
* that uses the ELF loader must provide this function.
*
* Input Parameters:
* rel - The relocation type
* sym - The ELF symbol structure containing the fully resolved value.
* There are a few relocation types for a few architectures that do
* not require symbol information. For those, this value will be
* NULL. Implementations of these functions must be able to handle
* that case.
* addr - The address that requires the relocation.
*
* Returned Value:
* Zero (OK) if the relocation was successful. Otherwise, a negated errno
* value indicating the cause of the relocation failure.
*
****************************************************************************/
int up_relocate(FAR const Elf32_Rel *rel, FAR const Elf32_Sym *sym,
uintptr_t addr)
{
FAR uint32_t *ptr = (FAR uint32_t *)addr;
/* All relocations depend upon having valid symbol information. */
if (sym == NULL)
{
return -EINVAL;
}
/* Handle the relocation by relocation type */
switch (ELF32_R_TYPE(rel->r_info))
{
case R_386_32:
*ptr += sym->st_value;
break;
case R_386_PC32:
*ptr += sym->st_value - (uint32_t)ptr;
break;
default:
return -EINVAL;
}
return OK;
}
int up_relocateadd(FAR const Elf32_Rela *rel, FAR const Elf32_Sym *sym,
uintptr_t addr)
{
bwarn("WARNING: Not supported\n");
return -ENOSYS;
}