From cb273fdad891d312c15110cd4eab95f5db39dcb2 Mon Sep 17 00:00:00 2001
From: Thomas Preud'homme <robotux@celest.fr>
Date: Sat, 12 Nov 2016 23:16:06 +0800
Subject: Do section relocation in architecture backend

---
 arm64-link.c | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 arm64-link.c

(limited to 'arm64-link.c')

diff --git a/arm64-link.c b/arm64-link.c
new file mode 100644
index 0000000..0364ba0
--- /dev/null
+++ b/arm64-link.c
@@ -0,0 +1,104 @@
+#include "tcc.h"
+#define HAVE_SECTION_RELOC
+
+void relocate_init(Section *sr) {}
+
+void relocate(TCCState *s1, ElfW_Rel *rel, int type, 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_AARCH64_ABS64:
+            write64le(ptr, val);
+            return;
+        case R_AARCH64_ABS32:
+            write32le(ptr, val);
+            return;
+        case R_AARCH64_MOVW_UABS_G0_NC:
+            write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
+                            (val & 0xffff) << 5));
+            return;
+        case R_AARCH64_MOVW_UABS_G1_NC:
+            write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
+                            (val >> 16 & 0xffff) << 5));
+            return;
+        case R_AARCH64_MOVW_UABS_G2_NC:
+            write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
+                            (val >> 32 & 0xffff) << 5));
+            return;
+        case R_AARCH64_MOVW_UABS_G3:
+            write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
+                            (val >> 48 & 0xffff) << 5));
+            return;
+        case R_AARCH64_ADR_PREL_PG_HI21: {
+            uint64_t off = (val >> 12) - (addr >> 12);
+            if ((off + ((uint64_t)1 << 20)) >> 21)
+                tcc_error("R_AARCH64_ADR_PREL_PG_HI21 relocation failed");
+            write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
+                            (off & 0x1ffffc) << 3 | (off & 3) << 29));
+            return;
+        }
+        case R_AARCH64_ADD_ABS_LO12_NC:
+            write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
+                            (val & 0xfff) << 10));
+            return;
+        case R_AARCH64_JUMP26:
+        case R_AARCH64_CALL26:
+	    /* This check must match the one in build_got_entries, testing
+	       if we really need a PLT slot.  */
+	    if (sym->st_shndx == SHN_UNDEF ||
+                s1->output_type == TCC_OUTPUT_MEMORY)
+	        /* We've put the PLT slot offset into r_addend when generating
+		   it, and that's what we must use as relocation value (adjusted
+		   by section offset of course).  */
+		val = s1->plt->sh_addr + rel->r_addend;
+#ifdef DEBUG_RELOC
+	    printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr, val,
+		    (char *) symtab_section->link->data + sym->st_name);
+#endif
+            if (((val - addr) + ((uint64_t)1 << 27)) & ~(uint64_t)0xffffffc)
+	      {
+                tcc_error("R_AARCH64_(JUMP|CALL)26 relocation failed (val=%lx, addr=%lx)", addr, val);
+	      }
+            write32le(ptr, (0x14000000 |
+                            (uint32_t)(type == R_AARCH64_CALL26) << 31 |
+                            ((val - addr) >> 2 & 0x3ffffff)));
+            return;
+        case R_AARCH64_ADR_GOT_PAGE: {
+            uint64_t off =
+                (((s1->got->sh_addr +
+                   s1->sym_attrs[sym_index].got_offset) >> 12) - (addr >> 12));
+            if ((off + ((uint64_t)1 << 20)) >> 21)
+                tcc_error("R_AARCH64_ADR_GOT_PAGE relocation failed");
+            write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
+                            (off & 0x1ffffc) << 3 | (off & 3) << 29));
+            return;
+        }
+        case R_AARCH64_LD64_GOT_LO12_NC:
+            write32le(ptr,
+                      ((read32le(ptr) & 0xfff803ff) |
+                       ((s1->got->sh_addr +
+                         s1->sym_attrs[sym_index].got_offset) & 0xff8) << 7));
+            return;
+        case R_AARCH64_COPY:
+            return;
+        case R_AARCH64_GLOB_DAT:
+        case R_AARCH64_JUMP_SLOT:
+            /* They don't need addend */
+#ifdef DEBUG_RELOC
+	    printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr,
+		    val - rel->r_addend,
+		    (char *) symtab_section->link->data + sym->st_name);
+#endif
+            write64le(ptr, val - rel->r_addend);
+            return;
+        default:
+            fprintf(stderr, "FIXME: handle reloc type %x at %x [%p] to %x\n",
+                    type, (unsigned)addr, ptr, (unsigned)val);
+            return;
+    }
+}
-- 
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