1
/*
2
 * ----------------------------------------------------------------------------
3
 * "THE BEER-WARE LICENSE" (Revision 42):
4
 * <[email protected]> wrote this file. As long as you retain this notice you can do
5
 * whatever you want with this stuff. If we meet some day, and you think this
6
 * stuff is worth it, you can buy me a beer in return.                     M4xw
7
 * ----------------------------------------------------------------------------
8
 */
9

10
#include "elfload.h"
11

12
#if defined(__arm__)
13

14
// Taken from http://infocenter.arm.com/help/topic/com.arm.doc.ihi0044f/IHI0044F_aaelf.pdf
15
#define R_ARM_NONE 0
16
#define R_ARM_ABS32 2
17
#define R_ARM_JUMP_SLOT 22
18
#define R_ARM_GLOB_DAT 21
19
#define R_ARM_RELATIVE 23
20

21
el_status el_applyrel(el_ctx *ctx, Elf_Rel *rel)
22
{
23
	u32 sym = ELF_R_SYM(rel->r_info);                              // Symbol offset
24
	u32 type = ELF_R_TYPE(rel->r_info);                            // Relocation Type
25
	uptr *p = (uptr *)(rel->r_offset + ctx->base_load_paddr); // Target Addr
26

27
#if 0 // For later symbol usage
28
	Elf32_Sym *elfSym;
29
	const char *symbolName;
30

31
	// We resolve relocs from the originating elf-image
32
	elfSym = (Elf32_Sym *)(ctx->symtab.sh_offset + (char *)buffteg) + sym;
33
	int strtab_offset = ctx->shstr.sh_offset;
34
	char *strtab = (char *)buffteg + strtab_offset;
35
	symbolName = strtab + elfSym->st_name;
36
	//EL_DEBUG("Str: %s sz: %x val: %x\n", symbolName, elfSym->st_size, elfSym->st_value);
37
#endif
38

39
	switch (type)
40
	{
41
	case R_ARM_NONE:
42
		EL_DEBUG("R_ARM_NONE\n");
43
		break;
44
	case R_ARM_JUMP_SLOT:
45
	case R_ARM_ABS32:
46
	case R_ARM_GLOB_DAT:
47
		// Stubbed for later purpose
48
		//*p += elfSym->st_value; // + vaddr from sec
49
		//*p |= 0; // 1 if Thumb && STT_FUNC, ignored for now
50
		break;
51
	case R_ARM_RELATIVE: // Needed for PIE
52
		if (sym)
53
		{
54
			return EL_BADREL;
55
		}
56
		*p += ctx->base_load_vaddr;
57
		break;
58

59
	default:
60
		return EL_BADREL;
61
	}
62

63
	return EL_OK;
64
}
65

66
#endif
67

68