New system for building kernel's config programs

From: Trent Piepho <xyzzy@speakeasy.org>

Since v4l-dvb now uses the kernel's config system, it needs certain kernel
binaries like qconf, mconf, and lxdialog to run the config targets.  The
kernel's Makefile is not kind enough to give us a target to just build these
programs.  What this patch does is introduce a new makefile,
Makefile.kernel, which includes the kernel's top-level Makefile.  Then adds
some new "v4l-*" targets which just build the kernel config programs.

The main v4l Makefile is patched to add the necessary kernel conf programs
as dependencies to their respective config targets.  Rules to build the
kernel conf programs are added which invoke a sub-make with the new
Makefile.kernel.  These rules are only invoked when the kernel conf programs
needed don't yet exist.  If they already exist, no write access to the
kernel source tree is needed.

Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 34 insertions, 44 deletions

diff --git a/v4l/Makefile b/v4l/Makefile
index b8eba1a44..6f86925a6 100644
--- a/v4l/Makefile
+++ b/v4l/Makefile
@@ -244,66 +244,56 @@ reload::
 #################################################
 # Configuration rules
 
-# SHELL used by kbuild
-CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
-          else if [ -x /bin/bash ]; then echo /bin/bash; \
-          else echo sh; fi ; fi)
-
-build := srctree=$(KDIR) HOSTCXX="$(CXX)" HOSTCC="$(HOSTCC)" CONFIG_SHELL="$(CONFIG_SHELL)" -f $(KDIR)/scripts/Makefile.build obj
-
-xconfig:: links .version
-	-if [ ! -f $(KDIR)/scripts/kconfig/qconf ]; then \
-		$(MAKE) -C $(KDIR) $(build)=scripts/kconfig qconf-target=1 scripts/kconfig/qconf; \
-	fi
+# Kernel config programs
+QCONF := $(KDIR)/scripts/kconfig/qconf
+GCONF := $(KDIR)/scripts/kconfig/gconf
+MCONF := $(KDIR)/scripts/kconfig/mconf
+CONF := $(KDIR)/scripts/kconfig/conf
+
+# lxdialog can be in either scripts/lxdialog or scripts/kconfig/lxdialog
+LXDIALOG_DIR := $(shell if [ -d $(KDIR)/scripts/kconfig/lxdialog ]; then echo kconfig/ ; fi)
+LXDIALOG_LNK := $(if $(LXDIALOG_DIR),scripts/kconfig,scripts/lxdialog)
+LXDIALOG := $(KDIR)/scripts/$(LXDIALOG_DIR)lxdialog/lxdialog
+
+xconfig:: links .version $(QCONF)
 	./scripts/make_kconfig.pl
-	$(KDIR)/scripts/kconfig/qconf Kconfig
+	$(QCONF) Kconfig
 	./scripts/make_noconfig.pl
 
-gconfig:: links .version
-	-if [ ! -f $(KDIR)/scripts/kconfig/gconf ]; then \
-		$(MAKE) -C $(KDIR) $(build)=scripts/kconfig scripts/kconfig/gconf; \
-	fi
+gconfig:: links .version $(GCONF)
 	./scripts/make_kconfig.pl
-	$(KDIR)/scripts/kconfig/gconf Kconfig
+	$(QCONF) Kconfig
 	./scripts/make_noconfig.pl
 
-config:: links .version
-	-if [ ! -f $(KDIR)/scripts/kconfig/conf ]; then \
-		$(MAKE) -C $(KDIR) $(build)=scripts/kconfig scripts/kconfig/conf; \
-	fi
+config:: links .version $(CONF)
 	./scripts/make_kconfig.pl
-	$(KDIR)/scripts/kconfig/conf Kconfig
+	$(CONF) Kconfig
 	./scripts/make_noconfig.pl
 
-menuconfig:: links .version
+menuconfig:: links .version $(MCONF) lxdialog
 	./scripts/make_kconfig.pl
-	-rm scripts/lxdialog scripts/kconfig
-	-if [ -d $(KDIR)/scripts/lxdialog ]; then \
-		if [ ! -f $(KDIR)/scripts/lxdialog/lxdialog ]; then \
-			$(MAKE) -C $(KDIR) $(build)=scripts/lxdialog; \
-		fi; \
-		ln -s $(KDIR)/scripts/lxdialog scripts/lxdialog; \
-	fi
-
-	-if [ -d $(KDIR)/scripts/kconfig ]; then \
-		if [  -d $(KDIR)/scripts/kconfig/lxdialog ]; then \
-			if [ ! -f $(KDIR)/scripts/kconfig/lxdialog ]; then \
-				$(MAKE) -C $(KDIR) $(build)=scripts/kconfig/lxdialog; \
-			fi; \
-		fi; \
-		if [ ! -f $(KDIR)/scripts/kconfig/mconf ]; then \
-			$(MAKE) -C $(KDIR) $(build)=scripts/kconfig scripts/kconfig/mconf; \
-		fi; \
-		ln -s $(KDIR)/scripts/kconfig scripts/kconfig; \
-	fi
-
-	$(KDIR)/scripts/kconfig/mconf Kconfig
+	$(MCONF) Kconfig
 	./scripts/make_noconfig.pl
 
 allyesconfig allmodconfig:: links .version
 	./scripts/make_kconfig.pl 1
 	./scripts/make_noconfig.pl
 
+# rule to build kernel conf programs
+KMAKEVARS := config-targets=1 mixed-targets=0 dot-config=0
+$(QCONF) $(GCONF) $(MCONF) $(CONF):
+	$(MAKE) -C $(KDIR) -f $(PWD)/Makefile.kernel $(KMAKEVARS) v4l-$(notdir $@)
+
+# lxdialog has two parts, a symlink and the actual binary
+.PHONY: lxdialog
+lxdialog: $(LXDIALOG) $(LXDIALOG_LNK)
+
+$(LXDIALOG_LNK):
+	ln -snf $(KDIR)/$(LXDIALOG_LNK) $(LXDIALOG_LNK)
+
+$(LXDIALOG):
+	$(MAKE) -C $(KDIR) -f $(PWD)/Makefile.kernel $(KMAKEVARS) v4l-$(LXDIALOG)
+
 #################################################
 # IVTV link rules