#  Makefile - hhl - /usr/src/world/linux-mainline
#  Copyright 2020 Nathan Fisher <nfisher.sr@gmail.com>
#
distname     = linux
default_goal = installkernel
include world.mk
srcdir       = $(basedir)/build/src-world-$(arch)/linux-$(linux_version)
objdir       = $(basedir)/build/obj-world-$(arch)/linux-$(linux_version)

config      ?= $(wkgdir)/config-$(arch)-$(linux_version).config

ifeq ($(filter x86_64 i486 i586 i686 i786, $(arch)), $(arch))
 _arch       = x86
 image       = bzImage
else ifeq ($(arch), armv7l)
 _arch       = arm
 image       = zImage
else
 image       = Image.gz
endif
ifeq ($(arch), aarch64)
 _arch       = arm64
else ifeq ($(arch), riscv64)
 _arch       = riscv
endif

installkernel: $(objdir)/.installed

buildkernel: $(objdir)/.built

$(objdir)/.mrproper: $(srcdir)/.dirstamp | $(objdir)
	$(MAKE) -C ${srcdir} mrproper
	touch $@

$(objdir)/.config: $(objdir)/.mrproper
	$(info $(grn)=== Applying default kernel config ===$(reset))
	cat ${config} > $(objdir)/.config
	KBUILD_OUTPUT=$(objdir) $(MAKE) -C $(srcdir) ARCH=$(_arch) CROSS_COMPILE=$(tgt)- olddefconfig

menuconfig: $(objdir)/.mrproper
	$(info $(grn)=== Applying default kernel config ===$(reset))
	cat ${config} > $(objdir)/.config
	KBUILD_OUTPUT=$(objdir) $(MAKE) -C $(srcdir) ARCH=$(_arch) CROSS_COMPILE=$(tgt)- olddefconfig
	KBUILD_OUTPUT=$(objdir) $(MAKE) -C $(srcdir) ARCH=$(_arch) CROSS_COMPILE=$(tgt)- menuconfig

$(objdir)/.built: $(objdir)/.config
	$(info $(grn)=== Building Linux kernel ===$(reset))
	KBUILD_OUTPUT=$(objdir) $(MAKE) $(makeflags) ARCH=$(_arch) CROSS_COMPILE=$(tgt)- -C $(srcdir)
	touch $@

$(objdir)/.modules_installed: $(objdir)/.built
	$(info $(grn)=== Installing kernel modules ===$(reset))
	KBUILD_OUTPUT=$(objdir) INSTALL_MOD_PATH=$(DESTDIR) $(MAKE) -C $(srcdir) modules_install
	touch $@

$(objdir)/.docs_installed: $(objdir)/.built
	$(info $(grn)=== Installing kernel documentation ===$(reset))
	install -d $(docdir)/linux-$(linux_version)
	cp -r $(srcdir)/Documentation/* $(docdir)/linux-$(linux_version)
	touch $@

$(objdir)/.installed: $(objdir)/.modules_installed $(objdir)/.docs_installed
	$(info $(grn)=== Installing kernel ===$(reset))
	install -m644 $(objdir)/arch/$(_arch)/boot/$(image) $(DESTDIR)/boot/vmlinuz-$(linux_version)-$(os_abbrev)-$(os_version)
	install -m644 $(objdir)/System.map $(DESTDIR)/boot/System.map-$(linux_version)
	install -m644 $(objdir)/.config $(DESTDIR)/boot/config-$(linux_version)
	touch $@

$(objdir):
	install -d ${objdir}

$(srcdir)/.dirstamp:
	$(info $(grn)=== Extracting $(distlocal) ===$(reset))
	tar -xf $(distlocal) -C $(basedir)/build/src-world
	touch $@

.PHONY: buildkernel installkernel