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/******************************************************************************
* Copyright (c) 2004, 2008 IBM Corporation
* All rights reserved.
* This program and the accompanying materials
* are made available under the terms of the BSD License
* which accompanies this distribution, and is available at
* http://www.opensource.org/licenses/bsd-license.php
*
* Contributors:
* IBM Corporation - initial implementation
*****************************************************************************/
/* this is elf.fs rewritten in C */
#include <string.h>
#include <cpu.h>
#include <libelf.h>
struct ehdr {
unsigned int ei_ident;
unsigned char ei_class;
unsigned char ei_data;
unsigned char ei_version;
unsigned char ei_pad[9];
unsigned short e_type;
unsigned short e_machine;
unsigned int e_version;
unsigned int e_entry;
unsigned int e_phoff;
unsigned int e_shoff;
unsigned int e_flags;
unsigned short e_ehsize;
unsigned short e_phentsize;
unsigned short e_phnum;
unsigned short e_shentsize;
unsigned short e_shnum;
unsigned short e_shstrndx;
};
struct phdr {
unsigned int p_type;
unsigned int p_offset;
unsigned int p_vaddr;
unsigned int p_paddr;
unsigned int p_filesz;
unsigned int p_memsz;
unsigned int p_flags;
unsigned int p_align;
};
struct ehdr64 {
unsigned int ei_ident;
unsigned char ei_class;
unsigned char ei_data;
unsigned char ei_version;
unsigned char ei_pad[9];
unsigned short e_type;
unsigned short e_machine;
unsigned int e_version;
unsigned long e_entry;
unsigned long e_phoff;
unsigned long e_shoff;
unsigned int e_flags;
unsigned short e_ehsize;
unsigned short e_phentsize;
unsigned short e_phnum;
unsigned short e_shentsize;
unsigned short e_shnum;
unsigned short e_shstrndx;
};
struct phdr64 {
unsigned int p_type;
unsigned int p_flags;
unsigned long p_offset;
unsigned long p_vaddr;
unsigned long p_paddr;
unsigned long p_filesz;
unsigned long p_memsz;
unsigned long p_align;
};
#define VOID(x) (void *)((unsigned long)x)
static void
load_segment(unsigned long *file_addr, struct phdr *phdr)
{
unsigned long src = phdr->p_offset + (unsigned long) file_addr;
/* copy into storage */
memmove(VOID(phdr->p_vaddr), VOID(src), phdr->p_filesz);
/* clear bss */
memset(VOID(phdr->p_vaddr + phdr->p_filesz), 0,
phdr->p_memsz - phdr->p_filesz);
if (phdr->p_memsz) {
flush_cache(VOID(phdr->p_vaddr), phdr->p_memsz);
}
}
static unsigned int
load_segments(unsigned long *file_addr)
{
struct ehdr *ehdr = (struct ehdr *) file_addr;
/* Calculate program header address */
struct phdr *phdr =
(struct phdr *) (((unsigned char *) file_addr) + ehdr->e_phoff);
int i;
/* loop e_phnum times */
for (i = 0; i <= ehdr->e_phnum; i++) {
/* PT_LOAD ? */
if (phdr->p_type == 1) {
/* copy segment */
load_segment(file_addr, phdr);
}
/* step to next header */
phdr =
(struct phdr *) (((unsigned char *) phdr) +
ehdr->e_phentsize);
}
return ehdr->e_entry;
}
static void
load_segment64(unsigned long *file_addr, struct phdr64 *phdr64)
{
unsigned long src = phdr64->p_offset + (unsigned long) file_addr;
/* copy into storage */
memmove(VOID(phdr64->p_vaddr), VOID(src), phdr64->p_filesz);
/* clear bss */
memset(VOID(phdr64->p_vaddr + phdr64->p_filesz), 0,
phdr64->p_memsz - phdr64->p_filesz);
if (phdr64->p_memsz) {
flush_cache(VOID(phdr64->p_vaddr), phdr64->p_memsz);
}
}
static unsigned long
load_segments64(unsigned long *file_addr)
{
struct ehdr64 *ehdr64 = (struct ehdr64 *) file_addr;
/* Calculate program header address */
struct phdr64 *phdr64 =
(struct phdr64 *) (((unsigned char *) file_addr) + ehdr64->e_phoff);
int i;
/* loop e_phnum times */
for (i = 0; i <= ehdr64->e_phnum; i++) {
/* PT_LOAD ? */
if (phdr64->p_type == 1) {
/* copy segment */
load_segment64(file_addr, phdr64);
}
/* step to next header */
phdr64 =
(struct phdr64 *) (((unsigned char *) phdr64) +
ehdr64->e_phentsize);
}
return ehdr64->e_entry;
}
#if __BYTE_ORDER == __BIG_ENDIAN
#define cpu_to_be32(x) (x)
#else
#define cpu_to_be32(x) bswap_32(x)
#endif
/**
* elf_check_file tests if the file at file_addr is
* a correct endian, ELF PPC executable
* @param file_addr pointer to the start of the ELF file
* @return the class (1 for 32 bit, 2 for 64 bit)
* -1 if it is not an ELF file
* -2 if it has the wrong endianess
* -3 if it is not an ELF executable
* -4 if it is not for PPC
*/
static int
elf_check_file(unsigned long *file_addr)
{
struct ehdr *ehdr = (struct ehdr *) file_addr;
/* check if it is an ELF image at all */
if (cpu_to_be32(ehdr->ei_ident) != 0x7f454c46)
return -1;
/* endian check */
#if __BYTE_ORDER == __BIG_ENDIAN
if (ehdr->ei_data != 2)
/* not a big endian image */
#else
if (ehdr->ei_data == 2)
/* not a little endian image */
#endif
return -2;
/* check if it is an ELF executable */
if (ehdr->e_type != 2)
return -3;
/* check if it is a PPC ELF executable */
if (ehdr->e_machine != 0x14 && ehdr->e_machine != 0x15)
return -4;
return ehdr->ei_class;
}
/**
* load_elf_file tries to load the ELF file specified in file_addr
*
* it first checks if the file is a PPC ELF executable and then loads
* the segments depending if it is a 64bit or 32 bit ELF file
*
* @param file_addr pointer to the start of the elf file
* @param entry pointer where the ELF loader will store
* the entry point
* @return 1 for a 32 bit file
* 2 for a 64 bit file
* anything else means an error during load
*/
int
load_elf_file(unsigned long *file_addr, unsigned long *entry)
{
int type = elf_check_file(file_addr);
switch (type) {
case 1:
*entry = load_segments(file_addr);
break;
case 2:
*entry = load_segments64(file_addr);
break;
}
return type;
}
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