ARM: Use proper Jamfiles for u-boot/arch/ subdirs

src/system/boot/platform/u-boot/Jamfile

@@ -27,9 +27,8 @@ local uImageFakeOS = "netbsd" ;
 
 SEARCH_SOURCE += [ FDirName $(HAIKU_TOP) src add-ons accelerants common ] ;
 
-KernelMergeObject boot_platform_u-boot.o :
-	shell.S
-	arch_start_kernel.S
+# First build the non arch dependent parts
+KernelMergeObject boot_platform_u-boot_common.o :
 	start2.cpp
 	debug.cpp
 	console.cpp
@@ -48,6 +47,13 @@ KernelMergeObject boot_platform_u-boot.o :
 	: boot_platform_generic.a
 ;
 
+KernelMergeObject boot_platform_u-boot.o :
+	: :
+	# must come first to have _start_* at correct locations
+	boot_platform_u-boot_$(TARGET_ARCH).o
+	boot_platform_u-boot_common.o
+;
+
 # include board-specific defs
 SubInclude HAIKU_TOP src system boot platform $(TARGET_BOOT_PLATFORM) board ;
 # reset SubDir
@@ -233,3 +239,5 @@ SEARCH on [ FGristFiles $(genericPlatformSources) ]
 # Tell the build system to where stage1.bin can be found, so it can be used
 # elsewhere.
 SEARCH on stage1.bin = $(SUBDIR) ;
+
+SubInclude HAIKU_TOP src system boot platform u-boot arch ;

src/system/boot/platform/u-boot/arch/Jamfile

@@ -0,0 +1,3 @@
+SubDir HAIKU_TOP src system boot platform u-boot arch ;
+
+SubInclude HAIKU_TOP src system boot platform u-boot arch $(TARGET_ARCH) ;

src/system/boot/platform/u-boot/arch/arm/Jamfile

@@ -0,0 +1,24 @@
+SubDir HAIKU_TOP src system boot platform u-boot arch arm ;
+
+SubDirHdrs $(HAIKU_TOP) src system boot platform $(TARGET_BOOT_PLATFORM) ;
+UsePrivateSystemHeaders ;
+UsePrivateHeaders kernel [ FDirName kernel arch $(TARGET_ARCH) ] 
+	[ FDirName kernel boot platform $(HAIKU_BOOT_PLATFORM) ] ;
+UsePrivateHeaders [ FDirName kernel arch $(TARGET_ARCH) board $(TARGET_BOOT_BOARD) ] ;
+
+SubDirC++Flags -fno-rtti ;
+
+KernelMergeObject boot_platform_u-boot_arm.o :
+	# must come first to have _start_* at correct locations
+	shell.S
+
+	#arch_mmu.cpp
+	#arch_cpu_asm.S
+	arch_start_kernel.S
+	#cpu.cpp
+	#mmu.cpp
+	: -fno-pic
+;
+
+#SEARCH on [ FGristFiles arch_cpu_asm.S arch_mmu.cpp ]
+#    = [ FDirName $(HAIKU_TOP) src system kernel arch $(TARGET_ARCH) ] ;