Merge branch 'devel' into araq

1 files changed, 392 insertions, 0 deletions

diff --git a/tinyc/arm-link.c b/tinyc/arm-link.c
new file mode 100644
index 000000000..aee35afef
--- /dev/null
+++ b/tinyc/arm-link.c
@@ -0,0 +1,392 @@
+#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 */