diff options
Diffstat (limited to 'tools/prelink-riscv.inc')
| -rw-r--r-- | tools/prelink-riscv.inc | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/tools/prelink-riscv.inc b/tools/prelink-riscv.inc new file mode 100644 index 0000000000..c07d930f7e --- /dev/null +++ b/tools/prelink-riscv.inc @@ -0,0 +1,112 @@ +/* + * Copyright (C) 2017 Andes Technology + * Chih-Mao Chen <cmchen@andestech.com> + * + * SPDX-License-Identifier: GPL-2.0+ + * + * 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 |