osd-contiki/cpu/at91sam7s/elfloader-arm.c

78 lines
2.3 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 */
void
elfloader_arch_relocate(int input_fd,
struct elfloader_output *output,
unsigned int sectionoffset,
char *sectionaddr,
struct elf32_rela *rela, char *addr)
{
unsigned int type;
unsigned char instr[4];
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:
{
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 (((*(uint16_t*)(instr+2)) & 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, *(uint16_t*)instr, *(uint16_t*)(instr+2), (int)offset, addr); */
*(uint16_t*)instr = (*(uint16_t*)instr & 0xf800) | ((offset>>12)&0x07ff);
*(uint16_t*)(instr+2) = ((*(uint16_t*)(instr+2) & 0xf800)
| ((offset>>1)&0x07ff));
elfloader_output_write_segment(output, (char*)instr, 4);
/* PRINTF("cfs_write: %04x %04x\n",*(uint16_t*)instr, *(uint16_t*)(instr+2)); */
}
break;
default:
PRINTF("elfloader-arm.c: unsupported relocation type %d\n", type);
break;
}
}