112 lines
3.0 KiB
C++
112 lines
3.0 KiB
C++
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* Copyright (C) 2017 Andes Technology
|
|
* Chih-Mao Chen <cmchen@andestech.com>
|
|
*
|
|
* Statically process runtime relocations on RISC-V ELF images
|
|
* so that it can be directly executed when loaded at LMA
|
|
* without fixup. Both RV32 and RV64 are supported.
|
|
*/
|
|
|
|
#define CONCAT_IMPL(x, y) x##y
|
|
#define CONCAT(x, y) CONCAT_IMPL(x, y)
|
|
#define CONCAT3(x, y, z) CONCAT(CONCAT(x, y), z)
|
|
|
|
#define prelink_nn CONCAT(prelink, PRELINK_INC_BITS)
|
|
#define uintnn_t CONCAT3(uint, PRELINK_INC_BITS, _t)
|
|
#define get_offset_nn CONCAT(get_offset_, PRELINK_INC_BITS)
|
|
#define Elf_Ehdr CONCAT3(Elf, PRELINK_INC_BITS, _Ehdr)
|
|
#define Elf_Phdr CONCAT3(Elf, PRELINK_INC_BITS, _Phdr)
|
|
#define Elf_Rela CONCAT3(Elf, PRELINK_INC_BITS, _Rela)
|
|
#define Elf_Sym CONCAT3(Elf, PRELINK_INC_BITS, _Sym)
|
|
#define Elf_Dyn CONCAT3(Elf, PRELINK_INC_BITS, _Dyn)
|
|
#define Elf_Addr CONCAT3(Elf, PRELINK_INC_BITS, _Addr)
|
|
#define ELF_R_TYPE CONCAT3(ELF, PRELINK_INC_BITS, _R_TYPE)
|
|
#define ELF_R_SYM CONCAT3(ELF, PRELINK_INC_BITS, _R_SYM)
|
|
|
|
static void* get_offset_nn (void* data, Elf_Phdr* phdrs, size_t phnum, Elf_Addr addr)
|
|
{
|
|
Elf_Phdr *p;
|
|
|
|
for (p = phdrs; p < phdrs + phnum; ++p)
|
|
if (p->p_vaddr <= addr && p->p_vaddr + p->p_memsz > addr)
|
|
return data + p->p_offset + (addr - p->p_vaddr);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void prelink_nn(void *data)
|
|
{
|
|
Elf_Ehdr *ehdr = data;
|
|
Elf_Phdr *p;
|
|
Elf_Dyn *dyn;
|
|
Elf_Rela *r;
|
|
|
|
if (ehdr->e_machine != EM_RISCV)
|
|
die("Machine type is not RISC-V");
|
|
|
|
Elf_Phdr *phdrs = data + ehdr->e_phoff;
|
|
|
|
Elf_Dyn *dyns = NULL;
|
|
for (p = phdrs; p < phdrs + ehdr->e_phnum; ++p) {
|
|
if (p->p_type == PT_DYNAMIC) {
|
|
dyns = data + p->p_offset;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (dyns == NULL)
|
|
die("No dynamic section found");
|
|
|
|
Elf_Rela *rela_dyn = NULL;
|
|
size_t rela_count = 0;
|
|
Elf_Sym *dynsym = NULL;
|
|
for (dyn = dyns;; ++dyn) {
|
|
if (dyn->d_tag == DT_NULL)
|
|
break;
|
|
else if (dyn->d_tag == DT_RELA)
|
|
rela_dyn = get_offset_nn(data, phdrs, ehdr->e_phnum, + dyn->d_un.d_ptr);
|
|
else if (dyn->d_tag == DT_RELASZ)
|
|
rela_count = dyn->d_un.d_val / sizeof(Elf_Rela);
|
|
else if (dyn->d_tag == DT_SYMTAB)
|
|
dynsym = get_offset_nn(data, phdrs, ehdr->e_phnum, + dyn->d_un.d_ptr);
|
|
|
|
}
|
|
|
|
if (rela_dyn == NULL)
|
|
die("No .rela.dyn found");
|
|
|
|
if (dynsym == NULL)
|
|
die("No .dynsym found");
|
|
|
|
for (r = rela_dyn; r < rela_dyn + rela_count; ++r) {
|
|
void* buf = get_offset_nn(data, phdrs, ehdr->e_phnum, r->r_offset);
|
|
|
|
if (buf == NULL)
|
|
continue;
|
|
|
|
if (ELF_R_TYPE(r->r_info) == R_RISCV_RELATIVE)
|
|
*((uintnn_t*) buf) = r->r_addend;
|
|
else if (ELF_R_TYPE(r->r_info) == R_RISCV_32)
|
|
*((uint32_t*) buf) = dynsym[ELF_R_SYM(r->r_info)].st_value;
|
|
else if (ELF_R_TYPE(r->r_info) == R_RISCV_64)
|
|
*((uint64_t*) buf) = dynsym[ELF_R_SYM(r->r_info)].st_value;
|
|
}
|
|
}
|
|
|
|
#undef prelink_nn
|
|
#undef uintnn_t
|
|
#undef get_offset_nn
|
|
#undef Elf_Ehdr
|
|
#undef Elf_Phdr
|
|
#undef Elf_Rela
|
|
#undef Elf_Sym
|
|
#undef Elf_Dyn
|
|
#undef Elf_Addr
|
|
#undef ELF_R_TYPE
|
|
#undef ELF_R_SYM
|
|
|
|
#undef CONCAT_IMPL
|
|
#undef CONCAT
|
|
#undef CONCAT3
|