[U-Boot] [PATCH] MIPS: fix endianess handling

[Daniel Schwierzeck]

Make endianess of target CPU configurable. Use the new config
option for dbau1550_el and pb1000 boards.

Adapt linking of standalone applications to pass through
endianess options to LD.

Build tested with:
 - ELDK 4 mips_4KC- and mips4KCle
 - Sourcery CodeBench Lite 2011.03-93

Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck at googlemail.com>
Cc: Thomas Lange <thomas at corelatus.se>
Cc: Mike Frysinger <vapier at gentoo.org>
Cc: Wolfgang Denk <wd at denx.de>
---
Another try to finally fix this originated by discussion:
[1] http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/118111/focus=118122

Related discussions:
[2] http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/81572
[3] http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/45404

 README                         |    6 ++++++
 arch/mips/cpu/mips32/config.mk |   21 +++++++++++++++------
 boards.cfg                     |    4 ++--
 examples/standalone/Makefile   |    6 +++++-
 4 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/README b/README
index 07f1d11..468bfdf 100644
--- a/README
+++ b/README
@@ -374,6 +374,12 @@ The following options need to be configured:
 		Defines the string to utilize when trying to match PCIe device
 		tree nodes for the given platform.
 
+- Generic CPU options:
+		CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
+
+		Defines the endianess of the CPU. Implementation of those
+		values is arch specific.
+
 - Intel Monahans options:
 		CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
 
diff --git a/arch/mips/cpu/mips32/config.mk b/arch/mips/cpu/mips32/config.mk
index 4d1b273..a1cd590 100644
--- a/arch/mips/cpu/mips32/config.mk
+++ b/arch/mips/cpu/mips32/config.mk
@@ -27,14 +27,23 @@
 # Note: Toolchains with binutils prior to v2.16
 # are no longer supported by U-Boot MIPS tree!
 #
-MIPSFLAGS = -march=mips32r2
+MIPSFLAGS := -march=mips32r2
 
+# Handle special prefix in ELDK 4.0 toolchain
 ifneq (,$(findstring 4KCle,$(CROSS_COMPILE)))
-ENDIANNESS = -EL
-else
-ENDIANNESS = -EB
+ENDIANNESS := -EL
 endif
 
-MIPSFLAGS += $(ENDIANNESS)
+ifdef CONFIG_SYS_LITTLE_ENDIAN
+ENDIANNESS := -EL
+endif
+
+ifdef CONFIG_SYS_BIG_ENDIAN
+ENDIANNESS := -EB
+endif
+
+# Default to EB if no endianess is configured
+ENDIANNESS ?= -EB
 
-PLATFORM_CPPFLAGS += $(MIPSFLAGS)
+PLATFORM_CPPFLAGS += $(MIPSFLAGS) $(ENDIANNESS)
+PLATFORM_LDFLAGS += $(ENDIANNESS)
diff --git a/boards.cfg b/boards.cfg
index c83d861..2cd917e 100644
--- a/boards.cfg
+++ b/boards.cfg
@@ -324,13 +324,13 @@ dbau1000                     mips        mips32      dbau1x00            -
 dbau1100                     mips        mips32      dbau1x00            -              au1x00      dbau1x00:DBAU1100
 dbau1500                     mips        mips32      dbau1x00            -              au1x00      dbau1x00:DBAU1500
 dbau1550                     mips        mips32      dbau1x00            -              au1x00      dbau1x00:DBAU1550
-dbau1550_el                  mips        mips32      dbau1x00            -              au1x00      dbau1x00:DBAU1550
+dbau1550_el                  mips        mips32      dbau1x00            -              au1x00      dbau1x00:DBAU1550,SYS_LITTLE_ENDIAN
 gth2                         mips        mips32      -                   -              au1x00
 incaip                       mips        mips32      incaip              -              incaip
 incaip_100MHz                mips        mips32      incaip              -              incaip      incaip:CPU_CLOCK_RATE=100000000
 incaip_133MHz                mips        mips32      incaip              -              incaip      incaip:CPU_CLOCK_RATE=133000000
 incaip_150MHz                mips        mips32      incaip              -              incaip      incaip:CPU_CLOCK_RATE=150000000
-pb1000                       mips        mips32      pb1x00              -              au1x00      pb1x00:PB1000
+pb1000                       mips        mips32      pb1x00              -              au1x00      pb1x00:PB1000,SYS_LITTLE_ENDIAN
 qemu_mips                    mips        mips32      qemu-mips           -              -           qemu-mips
 tb0229                       mips        mips32
 vct_premium                  mips        mips32      vct                 micronas       -           vct:VCT_PREMIUM
diff --git a/examples/standalone/Makefile b/examples/standalone/Makefile
index e23865b..eab23b4 100644
--- a/examples/standalone/Makefile
+++ b/examples/standalone/Makefile
@@ -88,6 +88,10 @@ endif
 CFLAGS_NTR := $(call cc-option,-fno-toplevel-reorder)
 CFLAGS += $(CFLAGS_NTR)
 
+# Pass through endianess settings in LDFLAGS to LD
+LDFLAGS_ENDIAN += $(filter -EB,$(LDFLAGS))
+LDFLAGS_ENDIAN += $(filter -EL,$(LDFLAGS))
+
 all:	$(obj).depend $(OBJS) $(LIB) $(SREC) $(BIN) $(ELF)
 
 #########################################################################
@@ -96,7 +100,7 @@ $(LIB):	$(obj).depend $(LIBOBJS)
 
 $(ELF):
 $(obj)%:	$(obj)%.o $(LIB)
-		$(LD) -g -Ttext $(CONFIG_STANDALONE_LOAD_ADDR) \
+		$(LD) $(LDFLAGS_ENDIAN) -g -Ttext $(CONFIG_STANDALONE_LOAD_ADDR) \
 			-o $@ -e $(SYM_PREFIX)$(notdir $(<:.o=)) $< $(LIB) \
 			-L$(gcclibdir) -lgcc
 
-- 
1.7.7.2