buildsystem: Determine the endianness only in the buildsystem

Let the buildsystem (make / meson) handle the endianness determination
and set the __FLASHROM_LITTLE_ENDIAN__ or __FLASHROM_BIG_ENDIAN__ macro
as cflag.

Change-Id: I37093528ae55e712cc30a0267a8ceac332750e7d
Signed-off-by: Thomas Heijligen <thomas.heijligen@secunet.de>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/58273
Original-Reviewed-by: Nico Huber <nico.h@gmx.de>
Original-Reviewed-by:  Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/72244
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/Makefile b/Makefile
index da092ce..d628f7d 100644
--- a/Makefile
+++ b/Makefile
@@ -248,6 +248,13 @@
 $(call mark_unsupported,CONFIG_INTERNAL)
 endif
 
+ifeq ($(ENDIAN), little)
+FEATURE_CFLAGS += -D'__FLASHROM_LITTLE_ENDIAN__=1'
+endif
+ifeq ($(ENDIAN), big)
+FEATURE_CFLAGS += -D'__FLASHROM_BIG_ENDIAN__=1'
+endif
+
 # PCI port I/O support is unimplemented on PPC/MIPS/SPARC and unavailable on ARM.
 # Right now this means the drivers below only work on x86.
 ifneq ($(ARCH), x86)
diff --git a/meson.build b/meson.build
index 1c7ffaa..28f15a0 100644
--- a/meson.build
+++ b/meson.build
@@ -29,6 +29,13 @@
 add_project_arguments('-D_BSD_SOURCE', language : 'c') # required for glibc < v2.19
 add_project_arguments('-DFLASHROM_VERSION="' + meson.project_version() + '"', language : 'c')
 
+if host_machine.endian() == 'little'
+  add_project_arguments('-D__FLASHROM_LITTLE_ENDIAN__=1', language : 'c')
+endif
+if host_machine.endian() == 'big'
+  add_project_arguments('-D__FLASHROM_BIG_ENDIAN__=1', language : 'c')
+endif
+
 # get defaults from configure
 config_atahpt = get_option('config_atahpt')
 config_atapromise = get_option('config_atapromise')
diff --git a/platform.h b/platform.h
index cd8e54b..9bbde54 100644
--- a/platform.h
+++ b/platform.h
@@ -71,93 +71,4 @@
 #error Unknown architecture
 #endif
 
-/* The next big hunk tries to guess endianness from various preprocessor macros */
-/* First some error checking in case some weird header has defined both.
- * NB: OpenBSD always defines _BIG_ENDIAN and _LITTLE_ENDIAN. */
-#if defined (__LITTLE_ENDIAN__) && defined (__BIG_ENDIAN__)
-#error Conflicting endianness #define
-#endif
-
-#if IS_X86
-
-/* All x86 is little-endian. */
-#define __FLASHROM_LITTLE_ENDIAN__ 1
-
-#elif IS_MIPS
-
-/* MIPS can be either endian. */
-#if defined (__MIPSEL) || defined (__MIPSEL__) || defined (_MIPSEL) || defined (MIPSEL)
-#define __FLASHROM_LITTLE_ENDIAN__ 1
-#elif defined (__MIPSEB) || defined (__MIPSEB__) || defined (_MIPSEB) || defined (MIPSEB)
-#define __FLASHROM_BIG_ENDIAN__ 1
-#endif
-
-#elif IS_PPC
-
-/* PowerPC can be either endian. */
-#if defined (_BIG_ENDIAN) || defined (__BIG_ENDIAN__)
-#define __FLASHROM_BIG_ENDIAN__ 1
-#elif defined (_LITTLE_ENDIAN) || defined (__LITTLE_ENDIAN__)
-#define __FLASHROM_LITTLE_ENDIAN__ 1
-#endif
-
-#elif IS_ARM
-
-/* ARM can be either endian. */
-#if defined (__ARMEB__) || defined (__BIG_ENDIAN__)
-#define __FLASHROM_BIG_ENDIAN__ 1
-#elif defined (__ARMEL__) || defined (__LITTLE_ENDIAN__)
-#define __FLASHROM_LITTLE_ENDIAN__ 1
-#endif
-
-#elif IS_SPARC
-/* SPARC is big endian in general (but allows to access data in little endian too). */
-#define __FLASHROM_BIG_ENDIAN__ 1
-
-#elif IS_ARC
-#if defined(__BIG_ENDIAN__)
-#define __FLASHROM_BIG_ENDIAN__ 1
-#else
-#define __FLASHROM_LITTLE_ENDIAN__ 1
-#endif
-
-#endif /* IS_? */
-
-#if !defined (__FLASHROM_BIG_ENDIAN__) && !defined (__FLASHROM_LITTLE_ENDIAN__)
-
-/* If architecture-specific approaches fail try generic variants. First: BSD (works about everywhere). */
-#if !IS_WINDOWS
-#include <sys/param.h>
-
-#if defined (__BYTE_ORDER)
-#if __BYTE_ORDER == __LITTLE_ENDIAN
-#define __FLASHROM_LITTLE_ENDIAN__
-#elif __BYTE_ORDER == __BIG_ENDIAN
-#define __FLASHROM_BIG_ENDIAN__
-#else
-#error Unknown byte order!
-#endif
-#endif /* defined __BYTE_ORDER */
-#endif /* !IS_WINDOWS */
-
-#if !defined (__FLASHROM_BIG_ENDIAN__) && !defined (__FLASHROM_LITTLE_ENDIAN__)
-
-/* Nonstandard libc-specific macros for determining endianness. */
-/* musl provides an endian.h as well... but it can not be detected from within C. */
-#if defined(__GLIBC__)
-#include <endian.h>
-#if BYTE_ORDER == LITTLE_ENDIAN
-#define __FLASHROM_LITTLE_ENDIAN__ 1
-#elif BYTE_ORDER == BIG_ENDIAN
-#define __FLASHROM_BIG_ENDIAN__ 1
-#endif
-#endif
-#endif
-
-#endif
-
-#if !defined (__FLASHROM_BIG_ENDIAN__) && !defined (__FLASHROM_LITTLE_ENDIAN__)
-#error Unable to determine endianness.
-#endif
-
 #endif /* !__PLATFORM_H__ */