Index: build/jam/BuildSetup
===================================================================
--- build/jam/BuildSetup	(revision 37496)
+++ build/jam/BuildSetup	(working copy)
@@ -165,12 +165,15 @@
 HAIKU_C++ ?= $(HAIKU_CC) ;
 HAIKU_LINK = $(HAIKU_CC) ;
 HAIKU_LINKFLAGS = $(HAIKU_GCC_BASE_FLAGS) ;
+HAIKU_BOOT_LINKFLAGS = ;
 
 HAIKU_HDRS = [ FStandardHeaders ] ;
 HAIKU_CCFLAGS = $(HAIKU_GCC_BASE_FLAGS) -nostdinc ;
 HAIKU_C++FLAGS = $(HAIKU_GCC_BASE_FLAGS) -nostdinc ;
 HAIKU_KERNEL_CCFLAGS = $(HAIKU_GCC_BASE_FLAGS) ;
 HAIKU_KERNEL_C++FLAGS = $(HAIKU_GCC_BASE_FLAGS) ;
+HAIKU_BOOT_CCFLAGS = ;
+HAIKU_BOOT_C++FLAGS = ;
 HAIKU_DEFINES = __HAIKU__ ;
 HAIKU_NO_WERROR ?= 0 ;
 
@@ -246,11 +249,11 @@
 	}
 	case x86_64 :
 	{
-		HAIKU_DEFINES += __x86_64__ ;
-		HAIKU_BOOT_PLATFORM = bios_ia32 ;
+		HAIKU_BOOT_PLATFORM = bios_x86_64 ;
 		HAIKU_BOOT_FLOPPY_IMAGE_SIZE = 2880 ; # in kB
 		# offset in floppy image (>= sizeof(haiku_loader))
 		HAIKU_BOOT_ARCHIVE_IMAGE_OFFSET = 300 ; # in kB
+		HAIKU_NO_WERROR = 1 ;
 
 		# yasm is required for target arch x86_64
 		if ! $(HAIKU_YASM) {
@@ -335,7 +338,6 @@
 		HAIKU_KERNEL_PIC_CCFLAGS = -fPIE ;
 		HAIKU_KERNEL_PIC_LINKFLAGS = -shared -fPIE ;
 	}
-
 	case m68k :
 	{
 		# We don't want to have to handle emulating missing FPU opcodes for 040
@@ -357,6 +359,15 @@
 	}
 	case x86_64 :
 	{
+		HAIKU_KERNEL_PIC_LINKFLAGS += -z max-page-size=0x1000 ;
+
+		HAIKU_KERNEL_PIC_CCFLAGS += -mcmodel=large ;
+		HAIKU_KERNEL_PIC_C++FLAGS += -mcmodel=large ;
+
+		HAIKU_BOOT_LINKFLAGS += -m elf_i386_haiku ;
+		HAIKU_BOOT_CCFLAGS += -m32 ;
+		HAIKU_BOOT_C++FLAGS += -m32 ;
+
 		# Enable use of the gcc built-in atomic functions instead of atomic_*().
 		# The former are inlined and have thus less overhead.
 		HAIKU_DEFINES += B_USE_BUILTIN_ATOMIC_FUNCTIONS ;
@@ -911,6 +922,7 @@
 	KERNEL_DEFINES
 
 	KERNEL_CCFLAGS KERNEL_C++FLAGS
+	BOOT_CCFLAGS BOOT_C++FLAGS BOOT_LINKFLAGS
 	KERNEL_PIC_CCFLAGS KERNEL_PIC_LINKFLAGS
 	WARNING_CCFLAGS WARNING_C++FLAGS
 
Index: build/scripts/build_cross_tools_gcc4
===================================================================
--- build/scripts/build_cross_tools_gcc4	(revision 37496)
+++ build/scripts/build_cross_tools_gcc4	(working copy)
@@ -27,6 +27,10 @@
 export MAKE
 
 case $haikuMachine in
+x86_64-*)
+	binutilsConfigureArgs="--enable-multilib"
+	gccConfigureArgs="--enable-multilib"
+	;;
 m68k-*)
 	binutilsConfigureArgs="--enable-multilib"
 	gccConfigureArgs="--enable-multilib"