[PATCH] Fix GPT build failure on big-endian architectures

[PATCH] Fix GPT build failure on big-endian architectures

[Colin Watson]

Big-endian (powerpc or sparc) builds of current trunk fail as follows:

  gcc-4.4 -DHAVE_CONFIG_H -I. -I../..           -Wall -W -I./include -DGRUB_UTIL=1 -DGRUB_LIBDIR=\"/usr/lib/grub\" -DLOCALEDIR=\"/usr/share/locale\"  -DGRUB_MACHINE_IEEE1275=1 -DGRUB_MACHINE_SPARC64=1 -DGRUB_MACHINE=SPARC64_IEEE1275 -DGRUB_FILE=\"grub-core/partmap/gpt.c\" -I. -I../.. -I. -I../.. -I../../include -I./include  -I../../grub-core/lib/libgcrypt_wrap            -I../../contrib/zfs/include             -g -Wall -O2  -Wno-error -Wno-missing-field-initializers               -c -o grub-core/partmap/libgrubmods_a-gpt.o `test -f 'grub-core/partmap/gpt.c' || echo '../../'`grub-core/partmap/gpt.c
  ../../grub-core/partmap/gpt.c:36: error: initializer element is not constant
  ../../grub-core/partmap/gpt.c:36: error: (near initialization for 'grub_gpt_partition_type_bios_boot.data1')
  ../../grub-core/partmap/gpt.c:36: error: braced-group within expression allowed only inside a function
  ../../grub-core/partmap/gpt.c:36: error: braced-group within expression allowed only inside a function
  make[4]: *** [grub-core/partmap/libgrubmods_a-gpt.o] Error 1

I think a reasonable approach would be to do the byte-swapping at module
initialisation time.  Does this patch look OK?

2010-11-22  Colin Watson  <cjwatson@ubuntu.com>

	* include/grub/gpt_partition.h (GRUB_GPT_PARTITION_TYPE_BIOS_BOOT):
	Remove byte-swapping function calls, which are not valid in
	structure initialisers.
	* grub-core/partmap/gpt.c (grub_gpt_partition_type_bios_boot): Make
	non-const.
	(GRUB_MOD_INIT): Byte-swap data1, data2, and data3 fields of
	grub_gpt_partition_type_bios_boot.

=== modified file 'grub-core/partmap/gpt.c'
--- grub-core/partmap/gpt.c	2010-09-24 12:05:47 +0000
+++ grub-core/partmap/gpt.c	2010-11-22 17:21:51 +0000
@@ -33,7 +33,7 @@ static grub_uint8_t grub_gpt_magic[8] =
 static const grub_gpt_part_type_t grub_gpt_partition_type_empty = GRUB_GPT_PARTITION_TYPE_EMPTY;
 
 #ifdef GRUB_UTIL
-static const grub_gpt_part_type_t grub_gpt_partition_type_bios_boot = GRUB_GPT_PARTITION_TYPE_BIOS_BOOT;
+static grub_gpt_part_type_t grub_gpt_partition_type_bios_boot = GRUB_GPT_PARTITION_TYPE_BIOS_BOOT;
 #endif
 
 /* 512 << 7 = 65536 byte sectors.  */
@@ -198,6 +198,14 @@ static struct grub_partition_map grub_gp
 GRUB_MOD_INIT(part_gpt)
 {
   grub_partition_map_register (&grub_gpt_partition_map);
+#ifdef GRUB_UTIL
+  grub_gpt_partition_type_bios_boot.data1 =
+    grub_cpu_to_le32 (grub_gpt_partition_type_bios_boot.data1);
+  grub_gpt_partition_type_bios_boot.data2 =
+    grub_cpu_to_le32 (grub_gpt_partition_type_bios_boot.data2);
+  grub_gpt_partition_type_bios_boot.data3 =
+    grub_cpu_to_le32 (grub_gpt_partition_type_bios_boot.data3);
+#endif
 }
 
 GRUB_MOD_FINI(part_gpt)

=== modified file 'include/grub/gpt_partition.h'
--- include/grub/gpt_partition.h	2009-04-19 20:38:46 +0000
+++ include/grub/gpt_partition.h	2010-11-22 17:21:21 +0000
@@ -36,7 +36,7 @@ typedef struct grub_gpt_part_type grub_g
   }
 
 #define GRUB_GPT_PARTITION_TYPE_BIOS_BOOT \
-  { grub_cpu_to_le32 (0x21686148), grub_cpu_to_le16 (0x6449), grub_cpu_to_le16 (0x6e6f), \
+  { 0x21686148, 0x6449, 0x6e6f, \
     { 0x74, 0x4e, 0x65, 0x65, 0x64, 0x45, 0x46, 0x49 } \
   }
 

-- 
Colin Watson                                       [cjwatson@ubuntu.com]

Re: [PATCH] Fix GPT build failure on big-endian architectures

[Colin Watson]

On Mon, Nov 22, 2010 at 11:31:40PM +0000, Colin Watson wrote:
> @@ -198,6 +198,14 @@ static struct grub_partition_map grub_gp
>  GRUB_MOD_INIT(part_gpt)
>  {
>    grub_partition_map_register (&grub_gpt_partition_map);
> +#ifdef GRUB_UTIL
> +  grub_gpt_partition_type_bios_boot.data1 =
> +    grub_cpu_to_le32 (grub_gpt_partition_type_bios_boot.data1);
> +  grub_gpt_partition_type_bios_boot.data2 =
> +    grub_cpu_to_le32 (grub_gpt_partition_type_bios_boot.data2);
> +  grub_gpt_partition_type_bios_boot.data3 =
> +    grub_cpu_to_le32 (grub_gpt_partition_type_bios_boot.data3);
> +#endif
>  }
>  
>  GRUB_MOD_FINI(part_gpt)
> 

Of course the second and third of these should have been
grub_cpu_to_le16.

I've gone ahead and applied this, with that correction; please do
correct me if you notice anything else wrong with it.

-- 
Colin Watson                                       [cjwatson@ubuntu.com]