nes-proj/cpu/at91sam7s/elfloader-arm.c
ksb b105b40e9a Added ELF-loader code, should probably eventually end up in core/loader.
Added some replacements for newlib's stdout.
Added missing startup code.
Some minor fixes.
2007-03-07 16:07:25 +00:00

96 lines
2.6 KiB
C

#include <malloc.h>
#include <loader/elfloader-arch-otf.h>
#if 0
#include <stdio.h>
#define PRINTF(...) printf(__VA_ARGS__)
#else
#define PRINTF(...) do {} while (0)
#endif
#define ELF32_R_TYPE(info) ((unsigned char)(info))
/* Supported relocations */
#define R_ARM_ABS32 2
#define R_ARM_THM_CALL 10
/* Adapted from elfloader-avr.c */
int
elfloader_arch_relocate(int input_fd,
struct elfloader_output *output,
unsigned int sectionoffset,
char *sectionaddr,
struct elf32_rela *rela, char *addr)
{
unsigned int type;
type = ELF32_R_TYPE(rela->r_info);
cfs_seek(input_fd, sectionoffset + rela->r_offset);
/* PRINTF("elfloader_arch_relocate: type %d\n", type); */
/* PRINTF("Addr: %p, Addend: %ld\n", addr, rela->r_addend); */
switch(type) {
case R_ARM_ABS32:
{
int32_t addend;
cfs_read(input_fd, (char*)&addend, 4);
addr += addend;
elfloader_output_write_segment(output,(char*) &addr, 4);
PRINTF("%p: addr: %p\n", sectionaddr +rela->r_offset,
addr);
}
break;
case R_ARM_THM_CALL:
{
uint16_t instr[2];
int32_t offset;
char *base;
cfs_read(input_fd, (char*)instr, 4);
/* Ignore the addend since it will be zero for calls to symbols,
and I can't think of a case when doing a relative call to
a non-symbol position */
base = sectionaddr + (rela->r_offset + 4);
if (((instr[1]) & 0xe800) == 0xe800) {
/* BL or BLX */
if (((uint32_t)addr) & 0x1) {
/* BL */
instr[1] |= 0x1800;
} else {
#if defined(__ARM_ARCH_4T__)
return ELFLOADER_UNHANDLED_RELOC;
#else
/* BLX */
instr[1] &= ~0x1800;
instr[1] |= 0x0800;
#endif
}
}
/* Adjust address for BLX */
if ((instr[1] & 0x1800) == 0x0800) {
addr = (char*)((((uint32_t)addr) & 0xfffffffd)
| (((uint32_t)base) & 0x00000002));
}
offset = addr - (sectionaddr + (rela->r_offset + 4));
if (offset < -(1<<22) || offset >= (1<<22)) {
PRINTF("elfloader-arm.c: offset %d too large for relative call\n",
(int)offset);
}
/* PRINTF("%p: %04x %04x offset: %d addr: %p\n", sectionaddr +rela->r_offset, instr[0], instr[1], (int)offset, addr); */
instr[0] = (instr[0] & 0xf800) | ((offset>>12)&0x07ff);
instr[1] = (instr[1] & 0xf800) | ((offset>>1)&0x07ff);
elfloader_output_write_segment(output, (char*)instr, 4);
/* PRINTF("cfs_write: %04x %04x\n",instr[0], instr[1]); */
}
break;
default:
PRINTF("elfloader-arm.c: unsupported relocation type %d\n", type);
return ELFLOADER_UNHANDLED_RELOC;
}
return ELFLOADER_OK;
}