build scripts: support for separate build and source directories

configure.ac

@@ -142,6 +142,7 @@ AC_CONFIG_FILES([
 	executer/user/Makefile
 	executer/kernel/Makefile
 	kernel/Makefile
+	kernel/Makefile.build
 	arch/x86/tools/mcreboot-attached-mic.sh
 	arch/x86/tools/mcshutdown-attached-mic.sh
 	arch/x86/tools/mcreboot.1:arch/x86/tools/mcreboot.1in

executer/kernel/Makefile.in

@@ -1,20 +1,21 @@
 KDIR ?= @KDIR@
 ARCH ?= @ARCH@
-src ?= $(shell pwd)
+src = @abs_srcdir@
 KMODDIR=@KMODDIR@
+IHK_BASE=$(src)/../../../ihk
 
 obj-m += mcctrl.o
 
-mcctrl-objs := driver.o control.o ikc.o syscall.o procfs.o
+ccflags-y := -I$(IHK_BASE)/linux/include -I$(IHK_BASE)/ikc/include -I$(IHK_BASE)/include -I$(src)/../include
 
-IHK_BASE=$(src)/../../../ihk
-EXTRA_CFLAGS = -I$(IHK_BASE)/linux/include -I$(IHK_BASE)/ikc/include -I$(IHK_BASE)/include -I$(src)/../include
-KBUILD_EXTRA_SYMBOLS = $(IHK_BASE)/linux/core/Module.symvers
+mcctrl-y := driver.o control.o ikc.o syscall.o procfs.o
+
+KBUILD_EXTRA_SYMBOLS = @abs_builddir@/../../../ihk/linux/core/Module.symvers
 
 .PHONY: clean install modules
 
 modules:
-	$(MAKE) -C $(KDIR) M=$(PWD) ARCH=$(ARCH) modules
+	$(MAKE) -C $(KDIR) M=$(PWD) SUBDIRS=$(PWD) ARCH=$(ARCH) modules
 
 clean:
 	$(RM) .*.cmd *.mod.c *.o *.ko* Module.symvers modules.order -r .tmp*

executer/user/Makefile.in

@@ -1,6 +1,7 @@
 CC=@CC@
 BINDIR=@BINDIR@
 CFLAGS=-Wall -O -fPIE -pie
+VPATH=@abs_srcdir@
 TARGET=mcexec
 
 all: $(TARGET)

kernel/Makefile.build.in

@@ -1,3 +1,5 @@
+VPATH=@abs_srcdir@
+SRC=$(VPATH)
 IHKDIR=$(IHKBASE)/$(TARGETDIR)
 OBJS = init.o mem.o debug.o mikc.o listeners.o ap.o syscall.o cls.o host.o
 OBJS += process.o copy.o waitq.o futex.o timer.o plist.o fileobj.o shmobj.o

kernel/Makefile.in

@@ -1,8 +1,8 @@
 BUILD_TARGET ?= @TARGET@
 KERNDIR=@KERNDIR@
-SRC = $(CURDIR)
+VPATH=@abs_srcdir@
 
-IHKBASE ?= $(SRC)/../../ihk/cokernel
+IHKBASE ?= $(VPATH)/../../ihk/cokernel
 O ?= $(CURDIR)/build
 V ?= $(VERBOSE)