diff options
Diffstat (limited to 'tinyc/arm-link.c')
| -rw-r--r-- | tinyc/arm-link.c | 392 |
1 files changed, 0 insertions, 392 deletions
diff --git a/tinyc/arm-link.c b/tinyc/arm-link.c deleted file mode 100644 index aee35afef..000000000 --- a/tinyc/arm-link.c +++ /dev/null @@ -1,392 +0,0 @@ -#ifdef TARGET_DEFS_ONLY - -#define EM_TCC_TARGET EM_ARM - -/* relocation type for 32 bit data relocation */ -#define R_DATA_32 R_ARM_ABS32 -#define R_DATA_PTR R_ARM_ABS32 -#define R_JMP_SLOT R_ARM_JUMP_SLOT -#define R_GLOB_DAT R_ARM_GLOB_DAT -#define R_COPY R_ARM_COPY -#define R_RELATIVE R_ARM_RELATIVE - -#define R_NUM R_ARM_NUM - -#define ELF_START_ADDR 0x00008000 -#define ELF_PAGE_SIZE 0x1000 - -#define PCRELATIVE_DLLPLT 1 -#define RELOCATE_DLLPLT 0 - -enum float_abi { - ARM_SOFTFP_FLOAT, - ARM_HARD_FLOAT, -}; - -#else /* !TARGET_DEFS_ONLY */ - -#include "tcc.h" - -/* Returns 1 for a code relocation, 0 for a data relocation. For unknown - relocations, returns -1. */ -int code_reloc (int reloc_type) -{ - switch (reloc_type) { - case R_ARM_MOVT_ABS: - case R_ARM_MOVW_ABS_NC: - case R_ARM_THM_MOVT_ABS: - case R_ARM_THM_MOVW_ABS_NC: - case R_ARM_ABS32: - case R_ARM_REL32: - case R_ARM_GOTPC: - case R_ARM_GOTOFF: - case R_ARM_GOT32: - case R_ARM_COPY: - case R_ARM_GLOB_DAT: - case R_ARM_NONE: - return 0; - - case R_ARM_PC24: - case R_ARM_CALL: - case R_ARM_JUMP24: - case R_ARM_PLT32: - case R_ARM_THM_PC22: - case R_ARM_THM_JUMP24: - case R_ARM_PREL31: - case R_ARM_V4BX: - case R_ARM_JUMP_SLOT: - return 1; - } - - tcc_error ("Unknown relocation type: %d", reloc_type); - return -1; -} - -/* Returns an enumerator to describe whether and when the relocation needs a - GOT and/or PLT entry to be created. See tcc.h for a description of the - different values. */ -int gotplt_entry_type (int reloc_type) -{ - switch (reloc_type) { - case R_ARM_NONE: - case R_ARM_COPY: - case R_ARM_GLOB_DAT: - case R_ARM_JUMP_SLOT: - return NO_GOTPLT_ENTRY; - - case R_ARM_PC24: - case R_ARM_CALL: - case R_ARM_JUMP24: - case R_ARM_PLT32: - case R_ARM_THM_PC22: - case R_ARM_THM_JUMP24: - case R_ARM_MOVT_ABS: - case R_ARM_MOVW_ABS_NC: - case R_ARM_THM_MOVT_ABS: - case R_ARM_THM_MOVW_ABS_NC: - case R_ARM_PREL31: - case R_ARM_ABS32: - case R_ARM_REL32: - case R_ARM_V4BX: - return AUTO_GOTPLT_ENTRY; - - case R_ARM_GOTPC: - case R_ARM_GOTOFF: - return BUILD_GOT_ONLY; - - case R_ARM_GOT32: - return ALWAYS_GOTPLT_ENTRY; - } - - tcc_error ("Unknown relocation type: %d", reloc_type); - return -1; -} - -ST_FUNC unsigned create_plt_entry(TCCState *s1, unsigned got_offset, struct sym_attr *attr) -{ - Section *plt = s1->plt; - uint8_t *p; - unsigned plt_offset; - - /* when building a DLL, GOT entry accesses must be done relative to - start of GOT (see x86_64 example above) */ - if (s1->output_type == TCC_OUTPUT_DLL) - tcc_error("DLLs unimplemented!"); - - /* empty PLT: create PLT0 entry that push address of call site and - jump to ld.so resolution routine (GOT + 8) */ - if (plt->data_offset == 0) { - p = section_ptr_add(plt, 20); - write32le(p, 0xe52de004); /* push {lr} */ - write32le(p+4, 0xe59fe004); /* ldr lr, [pc, #4] */ - write32le(p+8, 0xe08fe00e); /* add lr, pc, lr */ - write32le(p+12, 0xe5bef008); /* ldr pc, [lr, #8]! */ - /* p+16 is set in relocate_plt */ - } - plt_offset = plt->data_offset; - - if (attr->plt_thumb_stub) { - p = section_ptr_add(plt, 4); - write32le(p, 0x4778); /* bx pc */ - write32le(p+2, 0x46c0); /* nop */ - } - p = section_ptr_add(plt, 16); - /* Jump to GOT entry where ld.so initially put address of PLT0 */ - write32le(p, 0xe59fc004); /* ldr ip, [pc, #4] */ - write32le(p+4, 0xe08fc00c); /* add ip, pc, ip */ - write32le(p+8, 0xe59cf000); /* ldr pc, [ip] */ - /* p + 12 contains offset to GOT entry once patched by relocate_plt */ - write32le(p+12, got_offset); - return plt_offset; -} - -/* relocate the PLT: compute addresses and offsets in the PLT now that final - address for PLT and GOT are known (see fill_program_header) */ -ST_FUNC void relocate_plt(TCCState *s1) -{ - uint8_t *p, *p_end; - - if (!s1->plt) - return; - - p = s1->plt->data; - p_end = p + s1->plt->data_offset; - - if (p < p_end) { - int x = s1->got->sh_addr - s1->plt->sh_addr - 12; - write32le(s1->plt->data + 16, x - 16); - p += 20; - while (p < p_end) { - if (read32le(p) == 0x46c04778) /* PLT Thumb stub present */ - p += 4; - add32le(p + 12, x + s1->plt->data - p); - p += 16; - } - } -} - -void relocate_init(Section *sr) {} - -void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr, addr_t addr, addr_t val) -{ - ElfW(Sym) *sym; - int sym_index; - - sym_index = ELFW(R_SYM)(rel->r_info); - sym = &((ElfW(Sym) *)symtab_section->data)[sym_index]; - - switch(type) { - case R_ARM_PC24: - case R_ARM_CALL: - case R_ARM_JUMP24: - case R_ARM_PLT32: - { - int x, is_thumb, is_call, h, blx_avail, is_bl, th_ko; - x = (*(int *) ptr) & 0xffffff; -#ifdef DEBUG_RELOC - printf ("reloc %d: x=0x%x val=0x%x ", type, x, val); -#endif - (*(int *)ptr) &= 0xff000000; - if (x & 0x800000) - x -= 0x1000000; - x <<= 2; - blx_avail = (TCC_CPU_VERSION >= 5); - is_thumb = val & 1; - is_bl = (*(unsigned *) ptr) >> 24 == 0xeb; - is_call = (type == R_ARM_CALL || (type == R_ARM_PC24 && is_bl)); - x += val - addr; -#ifdef DEBUG_RELOC - printf (" newx=0x%x name=%s\n", x, - (char *) symtab_section->link->data + sym->st_name); -#endif - h = x & 2; - th_ko = (x & 3) && (!blx_avail || !is_call); - if (th_ko || x >= 0x2000000 || x < -0x2000000) - tcc_error("can't relocate value at %x,%d",addr, type); - x >>= 2; - x &= 0xffffff; - /* Only reached if blx is avail and it is a call */ - if (is_thumb) { - x |= h << 24; - (*(int *)ptr) = 0xfa << 24; /* bl -> blx */ - } - (*(int *) ptr) |= x; - } - return; - /* Since these relocations only concern Thumb-2 and blx instruction was - introduced before Thumb-2, we can assume blx is available and not - guard its use */ - case R_ARM_THM_PC22: - case R_ARM_THM_JUMP24: - { - int x, hi, lo, s, j1, j2, i1, i2, imm10, imm11; - int to_thumb, is_call, to_plt, blx_bit = 1 << 12; - Section *plt; - - /* weak reference */ - if (sym->st_shndx == SHN_UNDEF && - ELFW(ST_BIND)(sym->st_info) == STB_WEAK) - return; - - /* Get initial offset */ - hi = (*(uint16_t *)ptr); - lo = (*(uint16_t *)(ptr+2)); - s = (hi >> 10) & 1; - j1 = (lo >> 13) & 1; - j2 = (lo >> 11) & 1; - i1 = (j1 ^ s) ^ 1; - i2 = (j2 ^ s) ^ 1; - imm10 = hi & 0x3ff; - imm11 = lo & 0x7ff; - x = (s << 24) | (i1 << 23) | (i2 << 22) | - (imm10 << 12) | (imm11 << 1); - if (x & 0x01000000) - x -= 0x02000000; - - /* Relocation infos */ - to_thumb = val & 1; - plt = s1->plt; - to_plt = (val >= plt->sh_addr) && - (val < plt->sh_addr + plt->data_offset); - is_call = (type == R_ARM_THM_PC22); - - if (!to_thumb && !to_plt && !is_call) { - int index; - uint8_t *p; - char *name, buf[1024]; - Section *text_section; - - name = (char *) symtab_section->link->data + sym->st_name; - text_section = s1->sections[sym->st_shndx]; - /* Modify reloc to target a thumb stub to switch to ARM */ - snprintf(buf, sizeof(buf), "%s_from_thumb", name); - index = put_elf_sym(symtab_section, - text_section->data_offset + 1, - sym->st_size, sym->st_info, 0, - sym->st_shndx, buf); - to_thumb = 1; - val = text_section->data_offset + 1; - rel->r_info = ELFW(R_INFO)(index, type); - /* Create a thumb stub function to switch to ARM mode */ - put_elf_reloc(symtab_section, text_section, - text_section->data_offset + 4, R_ARM_JUMP24, - sym_index); - p = section_ptr_add(text_section, 8); - write32le(p, 0x4778); /* bx pc */ - write32le(p+2, 0x46c0); /* nop */ - write32le(p+4, 0xeafffffe); /* b $sym */ - } - - /* Compute final offset */ - x += val - addr; - if (!to_thumb && is_call) { - blx_bit = 0; /* bl -> blx */ - x = (x + 3) & -4; /* Compute offset from aligned PC */ - } - - /* Check that relocation is possible - * offset must not be out of range - * if target is to be entered in arm mode: - - bit 1 must not set - - instruction must be a call (bl) or a jump to PLT */ - if (!to_thumb || x >= 0x1000000 || x < -0x1000000) - if (to_thumb || (val & 2) || (!is_call && !to_plt)) - tcc_error("can't relocate value at %x,%d",addr, type); - - /* Compute and store final offset */ - s = (x >> 24) & 1; - i1 = (x >> 23) & 1; - i2 = (x >> 22) & 1; - j1 = s ^ (i1 ^ 1); - j2 = s ^ (i2 ^ 1); - imm10 = (x >> 12) & 0x3ff; - imm11 = (x >> 1) & 0x7ff; - (*(uint16_t *)ptr) = (uint16_t) ((hi & 0xf800) | - (s << 10) | imm10); - (*(uint16_t *)(ptr+2)) = (uint16_t) ((lo & 0xc000) | - (j1 << 13) | blx_bit | (j2 << 11) | - imm11); - } - return; - case R_ARM_MOVT_ABS: - case R_ARM_MOVW_ABS_NC: - { - int x, imm4, imm12; - if (type == R_ARM_MOVT_ABS) - val >>= 16; - imm12 = val & 0xfff; - imm4 = (val >> 12) & 0xf; - x = (imm4 << 16) | imm12; - if (type == R_ARM_THM_MOVT_ABS) - *(int *)ptr |= x; - else - *(int *)ptr += x; - } - return; - case R_ARM_THM_MOVT_ABS: - case R_ARM_THM_MOVW_ABS_NC: - { - int x, i, imm4, imm3, imm8; - if (type == R_ARM_THM_MOVT_ABS) - val >>= 16; - imm8 = val & 0xff; - imm3 = (val >> 8) & 0x7; - i = (val >> 11) & 1; - imm4 = (val >> 12) & 0xf; - x = (imm3 << 28) | (imm8 << 16) | (i << 10) | imm4; - if (type == R_ARM_THM_MOVT_ABS) - *(int *)ptr |= x; - else - *(int *)ptr += x; - } - return; - case R_ARM_PREL31: - { - int x; - x = (*(int *)ptr) & 0x7fffffff; - (*(int *)ptr) &= 0x80000000; - x = (x * 2) / 2; - x += val - addr; - if((x^(x>>1))&0x40000000) - tcc_error("can't relocate value at %x,%d",addr, type); - (*(int *)ptr) |= x & 0x7fffffff; - } - case R_ARM_ABS32: - *(int *)ptr += val; - return; - case R_ARM_REL32: - *(int *)ptr += val - addr; - return; - case R_ARM_GOTPC: - *(int *)ptr += s1->got->sh_addr - addr; - return; - case R_ARM_GOTOFF: - *(int *)ptr += val - s1->got->sh_addr; - return; - case R_ARM_GOT32: - /* we load the got offset */ - *(int *)ptr += s1->sym_attrs[sym_index].got_offset; - return; - case R_ARM_COPY: - return; - case R_ARM_V4BX: - /* trade Thumb support for ARMv4 support */ - if ((0x0ffffff0 & *(int*)ptr) == 0x012FFF10) - *(int*)ptr ^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */ - return; - case R_ARM_GLOB_DAT: - case R_ARM_JUMP_SLOT: - *(addr_t *)ptr = val; - return; - case R_ARM_NONE: - /* Nothing to do. Normally used to indicate a dependency - on a certain symbol (like for exception handling under EABI). */ - return; - default: - fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n", - type, (unsigned)addr, ptr, (unsigned)val); - return; - } -} - -#endif /* !TARGET_DEFS_ONLY */ |