Support grub-emu on x32 (ILP32 but with x86-64 instruction set)

* configure.ac: Remove -m64 from checks for -mcmodel=large and
-mno-red-zone.  These are always either unnecessary (x86_64-emu) or
already in TARGET_CFLAGS at this point, and they produce incorrect
results when building for x32.
* grub-core/kern/x86_64/dl.c (grub_arch_dl_relocate_symbols): Cast
pointers to Elf64_Xword via grub_addr_t, in order to work on x32.
* include/grub/x86_64/types.h (GRUB_TARGET_SIZEOF_VOID_P,
GRUB_TARGET_SIZEOF_LONG): Define to 4 on x32.

ChangeLog

@@ -1,3 +1,16 @@
+2014-09-07  Colin Watson  <[email protected]>
+
+	Support grub-emu on x32 (ILP32 but with x86-64 instruction set)
+
+	* configure.ac: Remove -m64 from checks for -mcmodel=large and
+	-mno-red-zone.  These are always either unnecessary (x86_64-emu) or
+	already in TARGET_CFLAGS at this point, and they produce incorrect
+	results when building for x32.
+	* grub-core/kern/x86_64/dl.c (grub_arch_dl_relocate_symbols): Cast
+	pointers to Elf64_Xword via grub_addr_t, in order to work on x32.
+	* include/grub/x86_64/types.h (GRUB_TARGET_SIZEOF_VOID_P,
+	GRUB_TARGET_SIZEOF_LONG): Define to 4 on x32.
+
 2014-09-07  Colin Watson  <[email protected]>
 
 	* configure.ac: Remove several unnecessary semicolons.

configure.ac

@@ -862,7 +862,7 @@ LDFLAGS="$TARGET_LDFLAGS"
 if test "$target_cpu" = x86_64 || test "$target_cpu-$platform" = sparc64-emu ; then
   # Use large model to support 4G memory
   AC_CACHE_CHECK([whether option -mcmodel=large works], grub_cv_cc_mcmodel, [
-    CFLAGS="$TARGET_CFLAGS -m64 -mcmodel=large"
+    CFLAGS="$TARGET_CFLAGS -mcmodel=large"
     AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
 		      [grub_cv_cc_mcmodel=yes],
 		      [grub_cv_cc_mcmodel=no])
@@ -877,7 +877,7 @@ fi
 if test "$target_cpu"-"$platform" = x86_64-efi; then
   # EFI writes to stack below %rsp, we must not use the red zone
   AC_CACHE_CHECK([whether option -mno-red-zone works], grub_cv_cc_no_red_zone, [
-    CFLAGS="$TARGET_CFLAGS -m64 -mno-red-zone"
+    CFLAGS="$TARGET_CFLAGS -mno-red-zone"
     AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
 		      [grub_cv_cc_no_red_zone=yes],
 		      [grub_cv_cc_no_red_zone=no])

grub-core/kern/x86_64/dl.c

@@ -73,7 +73,7 @@ grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr,
 	  {
 	    grub_int64_t value;
 	    value = ((grub_int32_t) *addr32) + rel->r_addend + sym->st_value -
-	      (Elf64_Xword) seg->addr - rel->r_offset;
+	      (Elf64_Xword) (grub_addr_t) seg->addr - rel->r_offset;
 	    if (value != (grub_int32_t) value)
 	      return grub_error (GRUB_ERR_BAD_MODULE, "relocation out of range");
 	    *addr32 = value;
@@ -83,7 +83,7 @@ grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr,
 	case R_X86_64_PC64:
 	  {
 	    *addr64 += rel->r_addend + sym->st_value -
-	      (Elf64_Xword) seg->addr - rel->r_offset;
+	      (Elf64_Xword) (grub_addr_t) seg->addr - rel->r_offset;
 	  }
 	  break;
 

include/grub/x86_64/types.h

@@ -20,10 +20,14 @@
 #define GRUB_TYPES_CPU_HEADER	1
 
 /* The size of void *.  */
+#ifdef __ILP32__
+#define GRUB_TARGET_SIZEOF_VOID_P	4
+#else
 #define GRUB_TARGET_SIZEOF_VOID_P	8
+#endif
 
 /* The size of long.  */
-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(__ILP32__)
 #define GRUB_TARGET_SIZEOF_LONG		4
 #else
 #define GRUB_TARGET_SIZEOF_LONG		8