blob: d49258707da4b7b1c32eae05c68b4c042b9fd200 [file] [log] [blame]
Tom Rini83d290c2018-05-06 17:58:06 -04001// SPDX-License-Identifier: GPL-2.0+
Rick Chen42ac26f2017-12-26 13:55:56 +08002/*
3 * Copyright (C) 2017 Andes Technology
4 * Chih-Mao Chen <cmchen@andestech.com>
5 *
Rick Chen42ac26f2017-12-26 13:55:56 +08006 * Statically process runtime relocations on RISC-V ELF images
7 * so that it can be directly executed when loaded at LMA
8 * without fixup. Both RV32 and RV64 are supported.
9 */
10
11#define CONCAT_IMPL(x, y) x##y
12#define CONCAT(x, y) CONCAT_IMPL(x, y)
13#define CONCAT3(x, y, z) CONCAT(CONCAT(x, y), z)
14
15#define prelink_nn CONCAT(prelink, PRELINK_INC_BITS)
16#define uintnn_t CONCAT3(uint, PRELINK_INC_BITS, _t)
17#define get_offset_nn CONCAT(get_offset_, PRELINK_INC_BITS)
18#define Elf_Ehdr CONCAT3(Elf, PRELINK_INC_BITS, _Ehdr)
19#define Elf_Phdr CONCAT3(Elf, PRELINK_INC_BITS, _Phdr)
20#define Elf_Rela CONCAT3(Elf, PRELINK_INC_BITS, _Rela)
21#define Elf_Sym CONCAT3(Elf, PRELINK_INC_BITS, _Sym)
22#define Elf_Dyn CONCAT3(Elf, PRELINK_INC_BITS, _Dyn)
23#define Elf_Addr CONCAT3(Elf, PRELINK_INC_BITS, _Addr)
24#define ELF_R_TYPE CONCAT3(ELF, PRELINK_INC_BITS, _R_TYPE)
25#define ELF_R_SYM CONCAT3(ELF, PRELINK_INC_BITS, _R_SYM)
26
27static void* get_offset_nn (void* data, Elf_Phdr* phdrs, size_t phnum, Elf_Addr addr)
28{
29 Elf_Phdr *p;
30
31 for (p = phdrs; p < phdrs + phnum; ++p)
32 if (p->p_vaddr <= addr && p->p_vaddr + p->p_memsz > addr)
33 return data + p->p_offset + (addr - p->p_vaddr);
34
35 return NULL;
36}
37
38static void prelink_nn(void *data)
39{
40 Elf_Ehdr *ehdr = data;
41 Elf_Phdr *p;
42 Elf_Dyn *dyn;
43 Elf_Rela *r;
44
45 if (ehdr->e_machine != EM_RISCV)
46 die("Machine type is not RISC-V");
47
48 Elf_Phdr *phdrs = data + ehdr->e_phoff;
49
50 Elf_Dyn *dyns = NULL;
51 for (p = phdrs; p < phdrs + ehdr->e_phnum; ++p) {
52 if (p->p_type == PT_DYNAMIC) {
53 dyns = data + p->p_offset;
54 break;
55 }
56 }
57
58 if (dyns == NULL)
59 die("No dynamic section found");
60
61 Elf_Rela *rela_dyn = NULL;
62 size_t rela_count = 0;
63 Elf_Sym *dynsym = NULL;
64 for (dyn = dyns;; ++dyn) {
65 if (dyn->d_tag == DT_NULL)
66 break;
67 else if (dyn->d_tag == DT_RELA)
68 rela_dyn = get_offset_nn(data, phdrs, ehdr->e_phnum, + dyn->d_un.d_ptr);
69 else if (dyn->d_tag == DT_RELASZ)
70 rela_count = dyn->d_un.d_val / sizeof(Elf_Rela);
71 else if (dyn->d_tag == DT_SYMTAB)
72 dynsym = get_offset_nn(data, phdrs, ehdr->e_phnum, + dyn->d_un.d_ptr);
73
74 }
75
76 if (rela_dyn == NULL)
77 die("No .rela.dyn found");
78
79 if (dynsym == NULL)
80 die("No .dynsym found");
81
82 for (r = rela_dyn; r < rela_dyn + rela_count; ++r) {
83 void* buf = get_offset_nn(data, phdrs, ehdr->e_phnum, r->r_offset);
84
85 if (buf == NULL)
86 continue;
87
88 if (ELF_R_TYPE(r->r_info) == R_RISCV_RELATIVE)
89 *((uintnn_t*) buf) = r->r_addend;
90 else if (ELF_R_TYPE(r->r_info) == R_RISCV_32)
91 *((uint32_t*) buf) = dynsym[ELF_R_SYM(r->r_info)].st_value;
92 else if (ELF_R_TYPE(r->r_info) == R_RISCV_64)
93 *((uint64_t*) buf) = dynsym[ELF_R_SYM(r->r_info)].st_value;
94 }
95}
96
97#undef prelink_nn
98#undef uintnn_t
99#undef get_offset_nn
100#undef Elf_Ehdr
101#undef Elf_Phdr
102#undef Elf_Rela
103#undef Elf_Sym
104#undef Elf_Dyn
105#undef Elf_Addr
106#undef ELF_R_TYPE
107#undef ELF_R_SYM
108
109#undef CONCAT_IMPL
110#undef CONCAT
111#undef CONCAT3