diff options
Diffstat (limited to 'grub-core/kern/riscv/dl.c')
| -rw-r--r-- | grub-core/kern/riscv/dl.c | 345 |
1 files changed, 345 insertions, 0 deletions
diff --git a/grub-core/kern/riscv/dl.c b/grub-core/kern/riscv/dl.c new file mode 100644 index 0000000..f26b12a --- /dev/null +++ b/grub-core/kern/riscv/dl.c @@ -0,0 +1,345 @@ +/* dl.c - arch-dependent part of loadable module support */ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2018 Free Software Foundation, Inc. + * + * GRUB is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * GRUB is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GRUB. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <grub/dl.h> +#include <grub/elf.h> +#include <grub/misc.h> +#include <grub/err.h> +#include <grub/mm.h> +#include <grub/i18n.h> + +/* + * Instructions and instruction encoding are documented in the RISC-V + * specification. This file is based on version 2.2: + * + * https://github.com/riscv/riscv-isa-manual/blob/master/release/riscv-spec-v2.2.pdf + */ +#define LDR 0x58000050 +#define BR 0xd61f0200 + +/* + * Check if EHDR is a valid ELF header. + */ +grub_err_t +grub_arch_dl_check_header (void *ehdr) +{ + Elf_Ehdr *e = ehdr; + + /* Check the magic numbers. */ + if (e->e_ident[EI_DATA] != ELFDATA2LSB || e->e_machine != EM_RISCV) + return grub_error (GRUB_ERR_BAD_OS, + N_("invalid arch-dependent ELF magic")); + + return GRUB_ERR_NONE; +} + +#pragma GCC diagnostic ignored "-Wcast-align" + +/* Relocate symbols. */ +grub_err_t +grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr, + Elf_Shdr *s, grub_dl_segment_t seg) +{ + Elf_Rel *rel, *max; + + for (rel = (Elf_Rel *) ((char *) ehdr + s->sh_offset), + max = (Elf_Rel *) ((char *) rel + s->sh_size); + rel < max; + rel = (Elf_Rel *) ((char *) rel + s->sh_entsize)) + { + Elf_Sym *sym; + void *place; + grub_size_t sym_addr; + + if (rel->r_offset >= seg->size) + return grub_error (GRUB_ERR_BAD_MODULE, + "reloc offset is out of the segment"); + + sym = (Elf_Sym *) ((char *) mod->symtab + + mod->symsize * ELF_R_SYM (rel->r_info)); + + sym_addr = sym->st_value; + if (s->sh_type == SHT_RELA) + sym_addr += ((Elf_Rela *) rel)->r_addend; + + place = (void *) ((grub_addr_t) seg->addr + rel->r_offset); + + switch (ELF_R_TYPE (rel->r_info)) + { + case R_RISCV_32: + { + grub_uint32_t *abs_place = place; + + grub_dprintf ("dl", " reloc_abs32 %p => 0x%016llx\n", + place, (unsigned long long) sym_addr); + + *abs_place = (grub_uint32_t) sym_addr; + } + break; + case R_RISCV_64: + { + grub_size_t *abs_place = place; + + grub_dprintf ("dl", " reloc_abs64 %p => 0x%016llx\n", + place, (unsigned long long) sym_addr); + + *abs_place = (grub_size_t) sym_addr; + } + break; + + case R_RISCV_ADD8: + { + grub_uint8_t *abs_place = place; + + *abs_place += (grub_uint8_t) sym_addr; + } + break; + case R_RISCV_ADD16: + { + grub_uint16_t *abs_place = place; + + *abs_place += (grub_uint16_t) sym_addr; + } + break; + case R_RISCV_ADD32: + { + grub_uint32_t *abs_place = place; + + *abs_place += (grub_uint32_t) sym_addr; + } + break; + case R_RISCV_ADD64: + { + grub_size_t *abs_place = place; + + *abs_place += (grub_size_t) sym_addr; + } + break; + + case R_RISCV_SUB8: + { + grub_uint8_t *abs_place = place; + + *abs_place -= (grub_uint8_t) sym_addr; + } + break; + case R_RISCV_SUB16: + { + grub_uint16_t *abs_place = place; + + *abs_place -= (grub_uint16_t) sym_addr; + } + break; + case R_RISCV_SUB32: + { + grub_uint32_t *abs_place = place; + + *abs_place -= (grub_uint32_t) sym_addr; + } + break; + case R_RISCV_SUB64: + { + grub_size_t *abs_place = place; + + *abs_place -= (grub_size_t) sym_addr; + } + break; + + case R_RISCV_BRANCH: + { + grub_uint32_t *abs_place = place; + grub_ssize_t off = sym_addr - (grub_addr_t) place; + grub_uint32_t imm12 = (off & 0x1000) << (31 - 12); + grub_uint32_t imm11 = (off & 0x800) >> (11 - 7); + grub_uint32_t imm10_5 = (off & 0x7e0) << (30 - 10); + grub_uint32_t imm4_1 = (off & 0x1e) << (11 - 4); + *abs_place = (*abs_place & 0x1fff07f) + | imm12 | imm11 | imm10_5 | imm4_1; + } + break; + + case R_RISCV_JAL: + { + grub_uint32_t *abs_place = place; + grub_ssize_t off = sym_addr - (grub_addr_t) place; + grub_uint32_t imm20 = (off & 0x100000) << (31 - 20); + grub_uint32_t imm19_12 = (off & 0xff000); + grub_uint32_t imm11 = (off & 0x800) << (20 - 11); + grub_uint32_t imm10_1 = (off & 0x7fe) << (30 - 10); + *abs_place = (*abs_place & 0xfff) + | imm20 | imm19_12 | imm11 | imm10_1; + } + break; + + case R_RISCV_CALL: + { + grub_uint32_t *abs_place = place; + grub_ssize_t off = sym_addr - (grub_addr_t) place; + grub_uint32_t hi20, lo12; + + if (off != (grub_int32_t) off) + return grub_error (GRUB_ERR_BAD_MODULE, "relocation overflow"); + + hi20 = (off + 0x800) & 0xfffff000; + lo12 = (off - hi20) & 0xfff; + abs_place[0] = (abs_place[0] & 0xfff) | hi20; + abs_place[1] = (abs_place[1] & 0xfffff) | (lo12 << 20); + } + break; + + case R_RISCV_RVC_BRANCH: + { + grub_uint16_t *abs_place = place; + grub_ssize_t off = sym_addr - (grub_addr_t) place; + grub_uint16_t imm8 = (off & 0x100) << (12 - 8); + grub_uint16_t imm7_6 = (off & 0xc0) >> (6 - 5); + grub_uint16_t imm5 = (off & 0x20) >> (5 - 2); + grub_uint16_t imm4_3 = (off & 0x18) << (12 - 5); + grub_uint16_t imm2_1 = (off & 0x6) << (12 - 10); + *abs_place = (*abs_place & 0xe383) + | imm8 | imm7_6 | imm5 | imm4_3 | imm2_1; + } + break; + + case R_RISCV_RVC_JUMP: + { + grub_uint16_t *abs_place = place; + grub_ssize_t off = sym_addr - (grub_addr_t) place; + grub_uint16_t imm11 = (off & 0x800) << (12 - 11); + grub_uint16_t imm10 = (off & 0x400) >> (10 - 8); + grub_uint16_t imm9_8 = (off & 0x300) << (12 - 11); + grub_uint16_t imm7 = (off & 0x80) >> (7 - 6); + grub_uint16_t imm6 = (off & 0x40) << (12 - 11); + grub_uint16_t imm5 = (off & 0x20) >> (5 - 2); + grub_uint16_t imm4 = (off & 0x10) << (12 - 5); + grub_uint16_t imm3_1 = (off & 0xe) << (12 - 10); + *abs_place = ((*abs_place & 0xe003) + | imm11 | imm10 | imm9_8 | imm7 | imm6 + | imm5 | imm4 | imm3_1); + } + break; + + case R_RISCV_PCREL_HI20: + { + grub_uint32_t *abs_place = place; + grub_ssize_t off = sym_addr - (grub_addr_t) place; + grub_int32_t hi20; + + if (off != (grub_int32_t)off) + return grub_error (GRUB_ERR_BAD_MODULE, "relocation overflow"); + + hi20 = (off + 0x800) & 0xfffff000; + *abs_place = (*abs_place & 0xfff) | hi20; + } + break; + + case R_RISCV_PCREL_LO12_I: + case R_RISCV_PCREL_LO12_S: + { + grub_uint32_t *t32 = place; + Elf_Rela *rel2; + /* Search backwards for matching HI20 reloc. */ + for (rel2 = (Elf_Rela *) ((char *) rel - s->sh_entsize); + (unsigned long)rel2 >= ((unsigned long)ehdr + s->sh_offset); + rel2 = (Elf_Rela *) ((char *) rel2 - s->sh_entsize)) + { + Elf_Addr rel2_info; + Elf_Addr rel2_offset; + Elf_Addr rel2_sym_addr; + Elf_Addr rel2_loc; + grub_ssize_t rel2_off; + grub_ssize_t off; + Elf_Sym *sym2; + + rel2_offset = rel2->r_offset; + rel2_info = rel2->r_info; + rel2_loc = (grub_addr_t) seg->addr + rel2_offset; + + if (ELF_R_TYPE (rel2_info) == R_RISCV_PCREL_HI20 + && rel2_loc == sym_addr) + { + sym2 = (Elf_Sym *) ((char *) mod->symtab + + mod->symsize * ELF_R_SYM (rel2->r_info)); + rel2_sym_addr = sym2->st_value; + if (s->sh_type == SHT_RELA) + rel2_sym_addr += ((Elf_Rela *) rel2)->r_addend; + + rel2_off = rel2_sym_addr - rel2_loc; + off = rel2_off - ((rel2_off + 0x800) & 0xfffff000); + + if (ELF_R_TYPE (rel->r_info) == R_RISCV_PCREL_LO12_I) + *t32 = (*t32 & 0xfffff) | (off & 0xfff) << 20; + else + { + grub_uint32_t imm11_5 = (off & 0xfe0) << (31 - 11); + grub_uint32_t imm4_0 = (off & 0x1f) << (11 - 4); + *t32 = (*t32 & 0x1fff07f) | imm11_5 | imm4_0; + } + break; + } + } + if ((unsigned long)rel2 < ((unsigned long)ehdr + s->sh_offset)) + return grub_error (GRUB_ERR_BAD_MODULE, "cannot find matching HI20 relocation"); + } + break; + + case R_RISCV_HI20: + { + grub_uint32_t *abs_place = place; + *abs_place = (*abs_place & 0xfff) | + (((grub_int32_t) sym_addr + 0x800) & 0xfffff000); + } + break; + + case R_RISCV_LO12_I: + { + grub_uint32_t *abs_place = place; + grub_int32_t lo12 = (grub_int32_t) sym_addr - + (((grub_int32_t) sym_addr + 0x800) & 0xfffff000); + *abs_place = (*abs_place & 0xfffff) | ((lo12 & 0xfff) << 20); + } + break; + + case R_RISCV_LO12_S: + { + grub_uint32_t *abs_place = place; + grub_int32_t lo12 = (grub_int32_t) sym_addr - + (((grub_int32_t) sym_addr + 0x800) & 0xfffff000); + grub_uint32_t imm11_5 = (lo12 & 0xfe0) << (31 - 11); + grub_uint32_t imm4_0 = (lo12 & 0x1f) << (11 - 4); + *abs_place = (*abs_place & 0x1fff07f) | imm11_5 | imm4_0; + } + break; + + case R_RISCV_RELAX: + break; + default: + { + char rel_info[17]; /* log16(2^64) = 16, plus NUL. */ + + grub_snprintf (rel_info, sizeof (rel_info) - 1, "%" PRIxGRUB_UINT64_T, + (grub_uint64_t) ELF_R_TYPE (rel->r_info)); + return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET, + N_("relocation 0x%s is not implemented yet"), rel_info); + } + } + } + + return GRUB_ERR_NONE; +} |