Change byte order detection mechanism to kernel style

The Linux Kernel defines only one of __LITTLE_ENDIAN and
__BIG_ENDIAN. Endianess can then be tested with #ifdef __xx_ENDIAN. Userspace
always defined both __LITTLE_ENDIAN and __BIG_ENDIAN and byteorder can then
be tested with #if __BYTE_ORDER == __xx_ENDIAN.

As we tend to use a lot of Kernel code in barebox we switch to use the kernel
way of determing the byte order.

As this always causes a lot of confusion add a check to include/common.h to
make sure only one of __LITTLE_ENDIAN and __BIG_ENDIAN is defined.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

drivers/ata/disk_ata_drive.c

@@ -231,7 +231,7 @@ static void __maybe_unused ata_dump_id(uint16_t *id)
  */
 static void ata_fix_endianess(uint16_t *buf, unsigned wds)
 {
-#if __BYTE_ORDER == __BIG_ENDIAN
+#ifdef __BIG_ENDIAN
 	unsigned u;
 
 	for (u = 0; u < wds; u++)

drivers/nor/cfi_flash.c

@@ -82,9 +82,9 @@ static void flash_add_byte (struct flash_info *info, cfiword_t * cword, uchar c)
 		return;
 	}
 
-#if __BYTE_ORDER == __BIG_ENDIAN
+#ifdef __BIG_ENDIAN
 	*cword = (*cword << 8) | c;
-#else
+#elif defined __LITTLE_ENDIAN
 
 	if (bankwidth_is_2(info))
 		*cword = (*cword >> 8) | (u16)c << 8;
@@ -92,6 +92,8 @@ static void flash_add_byte (struct flash_info *info, cfiword_t * cword, uchar c)
 		*cword = (*cword >> 8) | (u32)c << 24;
 	else if (bankwidth_is_8(info))
 		*cword = (*cword >> 8) | (u64)c << 56;
+#else
+#error "could not determine byte order"
 #endif
 }
 
@@ -167,7 +169,7 @@ static void flash_printqry (struct cfi_qry *qry)
 uchar flash_read_uchar (struct flash_info *info, uint offset)
 {
 	uchar *cp = flash_make_addr(info, 0, offset);
-#if __BYTE_ORDER == __LITTLE_ENDIAN
+#if defined __LITTLE_ENDIAN
 	return flash_read8(cp);
 #else
 	return flash_read8(cp + info->portwidth - 1);
@@ -195,7 +197,7 @@ static ulong flash_read_long (struct flash_info *info, flash_sect_t sect, uint o
 		debug ("addr[%x] = 0x%x\n", x, flash_read8(addr + x));
 	}
 #endif
-#if __BYTE_ORDER == __LITTLE_ENDIAN
+#if defined __LITTLE_ENDIAN
 	retval = ((flash_read8(addr) << 16) |
 		  (flash_read8(addr + info->portwidth) << 24) |
 		  (flash_read8(addr + 2 * info->portwidth)) |

include/common.h

@@ -34,6 +34,24 @@
 #include <linux/stddef.h>
 #include <asm/common.h>
 
+/*
+ * sanity check. The Linux Kernel defines only one of __LITTLE_ENDIAN and
+ * __BIG_ENDIAN. Endianess can then be tested with #ifdef __xx_ENDIAN. Userspace
+ * always defined both __LITTLE_ENDIAN and __BIG_ENDIAN and byteorder can then
+ * be tested with #if __BYTE_ORDER == __xx_ENDIAN.
+ *
+ * As we tend to use a lot of Kernel code in barebox we use the kernel way of
+ * determing the byte order. Make sure here that architecture code properly
+ * defines it.
+ */
+#include <asm/byteorder.h>
+#if defined __LITTLE_ENDIAN && defined __BIG_ENDIAN
+#error "both __LITTLE_ENDIAN and __BIG_ENDIAN are defined"
+#endif
+#if !defined __LITTLE_ENDIAN && !defined __BIG_ENDIAN
+#error "None of __LITTLE_ENDIAN and __BIG_ENDIAN are defined"
+#endif
+
 #define pr_info(fmt, arg...)	printf(fmt, ##arg)
 #define pr_notice(fmt, arg...)	printf(fmt, ##arg)
 #define pr_err(fmt, arg...)	printf(fmt, ##arg)

include/cramfs/cramfs_fs.h

@@ -84,11 +84,7 @@ struct cramfs_super {
 				| CRAMFS_FLAG_WRONG_SIGNATURE \
 				| CRAMFS_FLAG_SHIFTED_ROOT_OFFSET )
 
-#ifndef __BYTE_ORDER
-#error "No byte order defined in __BYTE_ORDER"
-#endif
-
-#if __BYTE_ORDER == __LITTLE_ENDIAN
+#ifdef __LITTLE_ENDIAN
 #define CRAMFS_16(x)	(x)
 #define CRAMFS_24(x)	(x)
 #define CRAMFS_32(x)	(x)
@@ -96,7 +92,7 @@ struct cramfs_super {
 #define CRAMFS_GET_OFFSET(x)	((x)->offset)
 #define CRAMFS_SET_OFFSET(x,y)	((x)->offset = (y))
 #define CRAMFS_SET_NAMELEN(x,y) ((x)->namelen = (y))
-#elif __BYTE_ORDER ==__BIG_ENDIAN
+#elif defined __BIG_ENDIAN
 #ifdef __KERNEL__
 #define CRAMFS_16(x)	swab16(x)
 #define CRAMFS_24(x)	((swab32(x)) >> 8)

include/envfs.h

@@ -34,11 +34,25 @@ struct envfs_super {
 	uint32_t sb_crc;		/* crc for the superblock */
 };
 
-#ifndef __BYTE_ORDER
-#error "No byte order defined in __BYTE_ORDER"
+#ifdef __BAREBOX__
+#  ifdef __LITTLE_ENDIAN
+#    define ENVFS_ORDER_LITTLE
+#  elif defined __BIG_ENDIAN
+#    define ENVFS_ORDER_BIG
+#  else
+#    error "could not determine byte order"
+#  endif
+#else
+#  if __BYTE_ORDER == __LITTLE_ENDIAN
+#    define ENVFS_ORDER_LITTLE
+#  elif __BYTE_ORDER == __BIG_ENDIAN
+#    define ENVFS_ORDER_BIG
+#  else
+#    error "could not determine byte order"
+#  endif
 #endif
 
-#if __BYTE_ORDER == __LITTLE_ENDIAN
+#ifdef ENVFS_ORDER_LITTLE
 #define ENVFS_16(x)	(x)
 #define ENVFS_24(x)	(x)
 #define ENVFS_32(x)	(x)
@@ -46,7 +60,7 @@ struct envfs_super {
 #define ENVFS_GET_OFFSET(x)	((x)->offset)
 #define ENVFS_SET_OFFSET(x,y)	((x)->offset = (y))
 #define ENVFS_SET_NAMELEN(x,y) ((x)->namelen = (y))
-#elif __BYTE_ORDER == __BIG_ENDIAN
+#elif defined ENVFS_ORDER_BIG
 #ifdef __KERNEL__
 #define ENVFS_16(x)	swab16(x)
 #define ENVFS_24(x)	((swab32(x)) >> 8)

include/linux/byteorder/generic.h

@@ -78,13 +78,6 @@
  *
  */
 
-#ifndef __LITTLE_ENDIAN
-#define __LITTLE_ENDIAN	1234
-#endif
-#ifndef __BIG_ENDIAN
-#define __BIG_ENDIAN	4321
-#endif
-
 #if defined(__KERNEL__)
 /*
  * inside the kernel, we can use nicknames;

include/usb/usb.h

@@ -270,12 +270,14 @@ void usb_rescan(void);
 		((x_ & 0xFF000000UL) >> 24)); \
 	})
 
-#if __BYTE_ORDER == __LITTLE_ENDIAN
+#ifdef __LITTLE_ENDIAN
 # define swap_16(x) (x)
 # define swap_32(x) (x)
-#else
+#elif defined BIG_ENDIAN
 # define swap_16(x) __swap_16(x)
 # define swap_32(x) __swap_32(x)
+#else
+#error "could not determine byte order"
 #endif
 
 /*