[PATCH] uml: allow building as 32-bit binary on 64bit host
This patch makes the command:
make ARCH=um SUBARCH=i386
work on x86_64 hosts (with support for building 32-bit binaries). This is
especially needed since 64-bit UMLs don't support 32-bit emulation for guest
binaries, currently. This has been tested in all possible cases and works.
Only exception is that I've built but not tested a 64-bit binary, because I
hadn't a 64-bit filesystem available.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/um/Makefile b/arch/um/Makefile
index 6a7a9f4..eb4ac40 100644
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -51,11 +51,6 @@
endif
SYS_DIR := $(ARCH_DIR)/include/sysdep-$(SUBARCH)
-include $(srctree)/$(ARCH_DIR)/Makefile-$(SUBARCH)
-
-core-y += $(SUBARCH_CORE)
-libs-y += $(SUBARCH_LIBS)
-
# -Dvmap=kernel_vmap affects everything, and prevents anything from
# referencing the libpcap.o symbol so named.
@@ -64,7 +59,7 @@
USER_CFLAGS := $(patsubst -I%,,$(CFLAGS))
USER_CFLAGS := $(patsubst -D__KERNEL__,,$(USER_CFLAGS)) $(ARCH_INCLUDE) \
- $(MODE_INCLUDE) $(ARCH_USER_CFLAGS)
+ $(MODE_INCLUDE)
# -Derrno=kernel_errno - This turns all kernel references to errno into
# kernel_errno to separate them from the libc errno. This allows -fno-common
@@ -74,6 +69,8 @@
CFLAGS += -Derrno=kernel_errno -Dsigprocmask=kernel_sigprocmask
CFLAGS += $(call cc-option,-fno-unit-at-a-time,)
+include $(srctree)/$(ARCH_DIR)/Makefile-$(SUBARCH)
+
#This will adjust *FLAGS accordingly to the platform.
include $(srctree)/$(ARCH_DIR)/Makefile-os-$(OS)
@@ -132,7 +129,7 @@
#The wrappers will select whether using "malloc" or the kernel allocator.
LINK_WRAPS = -Wl,--wrap,malloc -Wl,--wrap,free -Wl,--wrap,calloc
-CFLAGS_vmlinux = $(LINK-y) $(LINK_WRAPS)
+CFLAGS_vmlinux := $(LINK-y) $(LINK_WRAPS)
define cmd_vmlinux__
$(CC) $(CFLAGS_vmlinux) -o $@ \
-Wl,-T,$(vmlinux-lds) $(vmlinux-init) \
diff --git a/arch/um/Makefile-i386 b/arch/um/Makefile-i386
index 3010590..93d0818 100644
--- a/arch/um/Makefile-i386
+++ b/arch/um/Makefile-i386
@@ -1,4 +1,4 @@
-SUBARCH_CORE := arch/um/sys-i386/ arch/i386/crypto/
+core-y += arch/um/sys-i386/ arch/i386/crypto/
TOP_ADDR := $(CONFIG_TOP_ADDR)
@@ -8,21 +8,32 @@
endif
endif
+LDFLAGS += -m elf_i386
+ELF_ARCH := $(SUBARCH)
+ELF_FORMAT := elf32-$(SUBARCH)
+OBJCOPYFLAGS := -O binary -R .note -R .comment -S
+
+ifeq ("$(origin SUBARCH)", "command line")
+ifneq ("$(shell uname -m | sed -e s/i.86/i386/)", "$(SUBARCH)")
+CFLAGS += $(call cc-option,-m32)
+USER_CFLAGS += $(call cc-option,-m32)
+HOSTCFLAGS += $(call cc-option,-m32)
+HOSTLDFLAGS += $(call cc-option,-m32)
+AFLAGS += $(call cc-option,-m32)
+LINK-y += $(call cc-option,-m32)
+UML_OBJCOPYFLAGS += -F $(ELF_FORMAT)
+
+export LDFLAGS HOSTCFLAGS HOSTLDFLAGS UML_OBJCOPYFLAGS
+endif
+endif
+
CFLAGS += -U__$(SUBARCH)__ -U$(SUBARCH) $(STUB_CFLAGS)
-ARCH_USER_CFLAGS :=
ifneq ($(CONFIG_GPROF),y)
ARCH_CFLAGS += -DUM_FASTCALL
endif
-ELF_ARCH := $(SUBARCH)
-ELF_FORMAT := elf32-$(SUBARCH)
-
-OBJCOPYFLAGS := -O binary -R .note -R .comment -S
-
-SYS_UTIL_DIR := $(ARCH_DIR)/sys-i386/util
-
-SYS_HEADERS := $(SYS_DIR)/sc.h $(SYS_DIR)/thread.h
+SYS_HEADERS := $(SYS_DIR)/sc.h $(SYS_DIR)/thread.h
prepare: $(SYS_HEADERS)
diff --git a/arch/um/Makefile-x86_64 b/arch/um/Makefile-x86_64
index d80bd00..aa2f717 100644
--- a/arch/um/Makefile-x86_64
+++ b/arch/um/Makefile-x86_64
@@ -1,11 +1,13 @@
# Copyright 2003 - 2004 Pathscale, Inc
# Released under the GPL
-SUBARCH_LIBS := arch/um/sys-x86_64/
+libs-y += arch/um/sys-x86_64/
START := 0x60000000
+#We #undef __x86_64__ for kernelspace, not for userspace where
+#it's needed for headers to work!
CFLAGS += -U__$(SUBARCH)__ -fno-builtin $(STUB_CFLAGS)
-ARCH_USER_CFLAGS := -D__x86_64__
+USER_CFLAGS += -fno-builtin
ELF_ARCH := i386:x86-64
ELF_FORMAT := elf64-x86-64
diff --git a/arch/um/scripts/Makefile.unmap b/arch/um/scripts/Makefile.unmap
index 37a8f97..802d027 100644
--- a/arch/um/scripts/Makefile.unmap
+++ b/arch/um/scripts/Makefile.unmap
@@ -12,8 +12,8 @@
quiet_cmd_wrapld = LD $@
define cmd_wrapld
- $(LD) -r -o $(obj)/unmap_tmp.o $< $(shell $(CC) -print-file-name=libc.a); \
- $(OBJCOPY) $(obj)/unmap_tmp.o $@ -G switcheroo
+ $(LD) $(LDFLAGS) -r -o $(obj)/unmap_tmp.o $< $(shell $(CC) $(CFLAGS) -print-file-name=libc.a); \
+ $(OBJCOPY) $(UML_OBJCOPYFLAGS) $(obj)/unmap_tmp.o $@ -G switcheroo
endef
$(obj)/unmap_fin.o : $(obj)/unmap.o FORCE