ARM: add support for R_ARM_V4BX

2 files changed, 11 insertions, 1 deletions

diff --git a/elf.h b/elf.h
index 8ecadd1..d6b1c6a 100644
--- a/elf.h
+++ b/elf.h
@@ -1673,6 +1673,7 @@ typedef Elf32_Addr Elf32_Conflict;
 #define R_ARM_PLT32             27      /* 32 bit PLT address */
 #define R_ARM_CALL              28
 #define R_ARM_JUMP24            29
+#define R_ARM_V4BX              40
 #define R_ARM_PREL31            42
 #define R_ARM_GNU_VTENTRY       100
 #define R_ARM_GNU_VTINHERIT     101
diff --git a/tccelf.c b/tccelf.c
index 037615a..526c513 100644
--- a/tccelf.c
+++ b/tccelf.c
@@ -660,6 +660,11 @@ ST_FUNC void relocate_section(TCCState *s1, Section *s)
             break;
         case R_ARM_COPY:
             break;
+        case R_ARM_V4BX:
+            /* trade Thumb support for ARMv4 support */
+            if ((0x0ffffff0 & *(int*)ptr) == 0x012FFF10)
+                *(int*)ptr ^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */
+            break;
         default:
             fprintf(stderr,"FIXME: handle reloc type %x at %lx [%.8x] to %lx\n",
                     type,addr,(unsigned int)(long)ptr,val);
@@ -2474,7 +2479,11 @@ ST_FUNC int tcc_load_object_file(TCCState *s1,
                     goto invalid_reloc;
                 sym_index = old_to_new_syms[sym_index];
                 /* ignore link_once in rel section. */
-                if (!sym_index && !sm->link_once) {
+                if (!sym_index && !sm->link_once
+#ifdef TCC_TARGET_ARM
+                    && type != R_ARM_V4BX
+#endif
+                   ) {
                 invalid_reloc:
                     error_noabort("Invalid relocation entry [%2d] '%s' @ %.8x",
                         i, strsec + sh->sh_name, rel->r_offset);