SUMMARY = "Linux kernel Development Source"
DESCRIPTION = "Development source linux kernel. When built, this recipe packages the \
source of the preferred virtual/kernel provider and makes it available for full kernel \
development or external module builds"

SECTION = "kernel"

LICENSE = "GPLv2"

inherit linux-kernel-base

# Whilst not a module, this ensures we don't get multilib extended (which would make no sense)
inherit module-base

# We need the kernel to be staged (unpacked, patched and configured) before
# we can grab the source and make the source package. We also need the bits from
# ${B} not to change while we install, so virtual/kernel must finish do_compile.
do_install[depends] += "virtual/kernel:do_shared_workdir"
# Need the source, not just the output of populate_sysroot
do_install[depends] += "virtual/kernel:do_install"

# There's nothing to do here, except install the source where we can package it
do_fetch[noexec] = "1"
do_unpack[noexec] = "1"
do_patch[noexec] = "1"
do_configure[noexec] = "1"
do_compile[noexec] = "1"
deltask do_populate_sysroot

S = "${STAGING_KERNEL_DIR}"
B = "${STAGING_KERNEL_BUILDDIR}"

PACKAGE_ARCH = "${MACHINE_ARCH}"

KERNEL_BUILD_ROOT="${nonarch_base_libdir}/modules/"

do_install() {
    kerneldir=${D}${KERNEL_BUILD_ROOT}${KERNEL_VERSION}
    install -d $kerneldir

    # create the directory structure
    rm -f $kerneldir/build
    rm -f $kerneldir/source
    mkdir -p $kerneldir/build

    # for compatibility with some older variants of this package, we
    # create  a /usr/src/kernel symlink to /lib/modules/<version>/source
    mkdir -p ${D}/usr/src
    (
	cd ${D}/usr/src
	lnr ${D}${KERNEL_BUILD_ROOT}${KERNEL_VERSION}/source kernel
    )

    # for on target purposes, we unify build and source
    (
	cd $kerneldir
	ln -s build source
    )

    # first copy everything
    (
	cd ${S}
	cp --parents $(find  -type f -name "Makefile*" -o -name "Kconfig*") $kerneldir/build
	cp --parents $(find  -type f -name "Build" -o -name "Build.include") $kerneldir/build
    )

    # then drop all but the needed Makefiles/Kconfig files
    rm -rf $kerneldir/build/Documentation
    rm -rf $kerneldir/build/scripts
    rm -rf $kerneldir/build/include

    # now copy in parts from the build that we'll need later
    (
	cd ${B}

	cp Module.symvers $kerneldir/build
	cp System.map* $kerneldir/build
	if [ -s Module.markers ]; then
	    cp Module.markers $kerneldir/build
	fi

	cp .config $kerneldir/build

	# This scripts copy blow up QA, so for now, we require a more
	# complex 'make scripts' to restore these, versus copying them
	# here. Left as a reference to indicate that we know the scripts must
	# be dealt with.
	# cp -a scripts $kerneldir/build

        if [ -d arch/${ARCH}/scripts ]; then
	    cp -a arch/${ARCH}/scripts $kerneldir/build/arch/${ARCH}
	fi
	if [ -f arch/${ARCH}/*lds ]; then
	    cp -a arch/${ARCH}/*lds $kerneldir/build/arch/${ARCH}
	fi

	rm -f $kerneldir/build/scripts/*.o
	rm -f $kerneldir/build/scripts/*/*.o

	if [ "${ARCH}" = "powerpc" ]; then
	    if [ -e arch/powerpc/lib/crtsavres.S ] ||
		   [ -e arch/powerpc/lib/crtsavres.o ]; then
		cp -a --parents arch/powerpc/lib/crtsavres.[So] $kerneldir/build/
	    fi
	fi

	if [ "${ARCH}" = "arm64" ]; then
	    cp -a --parents arch/arm64/kernel/vdso/vdso.lds $kerneldir/build/
	fi

	cp -a include $kerneldir/build/include
    )

    # now grab the chunks from the source tree that we need
    (
	cd ${S}

	cp -a scripts $kerneldir/build

	# if our build dir had objtool, it will also be rebuilt on target, so
	# we copy what is required for that build
	if [ -f ${B}/tools/objtool/objtool ]; then
	    # these are a few files associated with objtool, since we'll need to
	    # rebuild it
	    cp -a --parents tools/build/Build.include $kerneldir/build/
	    cp -a --parents tools/build/Build $kerneldir/build/
	    cp -a --parents tools/build/fixdep.c $kerneldir/build/
	    cp -a --parents tools/scripts/utilities.mak $kerneldir/build/

	    # extra files, just in case
	    cp -a --parents tools/objtool/* $kerneldir/build/
	    cp -a --parents tools/lib/str_error_r.c $kerneldir/build/
	    cp -a --parents tools/lib/string.c $kerneldir/build/
	    cp -a --parents tools/lib/subcmd/* $kerneldir/build/

	    cp -a --parents tools/include/* $kerneldir/build/
	fi

	if [ "${ARCH}" = "arm64" ]; then
	    # arch/arm64/include/asm/xen references arch/arm
	    cp -a --parents arch/arm/include/asm/xen $kerneldir/build/
	    # arch/arm64/include/asm/opcodes.h references arch/arm
	    cp -a --parents arch/arm/include/asm/opcodes.h $kerneldir/build/

            cp -a --parents arch/arm64/kernel/vdso/gettimeofday.S $kerneldir/build/
            cp -a --parents arch/arm64/kernel/vdso/sigreturn.S $kerneldir/build/
            cp -a --parents arch/arm64/kernel/vdso/note.S $kerneldir/build/
            cp -a --parents arch/arm64/kernel/vdso/gen_vdso_offsets.sh $kerneldir/build/

            cp -a --parents arch/arm64/kernel/module.lds $kerneldir/build/
	fi

	if [ "${ARCH}" = "powerpc" ]; then
	    # 5.0 needs these files, but don't error if they aren't present in the source
	    cp -a --parents arch/${ARCH}/kernel/syscalls/syscall.tbl $kerneldir/build/ 2>/dev/null || :
	    cp -a --parents arch/${ARCH}/kernel/syscalls/syscalltbl.sh $kerneldir/build/ 2>/dev/null || :
	    cp -a --parents arch/${ARCH}/kernel/syscalls/syscallhdr.sh $kerneldir/build/ 2>/dev/null || :
	fi

	# include the machine specific headers for ARM variants, if available.
	if [ "${ARCH}" = "arm" ]; then
	    cp -a --parents arch/${ARCH}/mach-*/include $kerneldir/build/

	    # include a few files for 'make prepare'
	    cp -a --parents arch/arm/tools/gen-mach-types $kerneldir/build/
	    cp -a --parents arch/arm/tools/mach-types $kerneldir/build/

	    # ARM syscall table tools only exist for kernels v4.10 or later
            SYSCALL_TOOLS=$(find arch/arm/tools -name "syscall*")
            if [ -n "$SYSCALL_TOOLS" ] ; then
	        cp -a --parents $SYSCALL_TOOLS $kerneldir/build/
            fi

            cp -a --parents arch/arm/kernel/module.lds $kerneldir/build/
	fi

	if [ -d arch/${ARCH}/include ]; then
	    cp -a --parents arch/${ARCH}/include $kerneldir/build/
	fi

	cp -a include $kerneldir/build

	cp -a --parents tools/include/tools/le_byteshift.h $kerneldir/build/
	cp -a --parents tools/include/tools/be_byteshift.h $kerneldir/build/

	# required for generate missing syscalls prepare phase
	cp -a --parents arch/x86/entry/syscalls/syscall_32.tbl $kerneldir/build

	if [ "${ARCH}" = "x86" ]; then
	    # files for 'make prepare' to succeed with kernel-devel
	    cp -a --parents arch/x86/entry/syscalls/syscall_32.tbl $kerneldir/build/
	    cp -a --parents arch/x86/entry/syscalls/syscalltbl.sh $kerneldir/build/
	    cp -a --parents arch/x86/entry/syscalls/syscallhdr.sh $kerneldir/build/
	    cp -a --parents arch/x86/entry/syscalls/syscall_64.tbl $kerneldir/build/
	    cp -a --parents arch/x86/tools/relocs_32.c $kerneldir/build/
	    cp -a --parents arch/x86/tools/relocs_64.c $kerneldir/build/
	    cp -a --parents arch/x86/tools/relocs.c $kerneldir/build/
	    cp -a --parents arch/x86/tools/relocs_common.c $kerneldir/build/
	    cp -a --parents arch/x86/tools/relocs.h $kerneldir/build/
	    cp -a --parents arch/x86/purgatory/purgatory.c $kerneldir/build/

	    # 4.18 + have unified the purgatory files, so we ignore any errors if
	    # these files are not present
	    cp -a --parents arch/x86/purgatory/sha256.h $kerneldir/build/ 2>/dev/null || :
	    cp -a --parents arch/x86/purgatory/sha256.c $kerneldir/build/ 2>/dev/null || :

	    cp -a --parents arch/x86/purgatory/stack.S $kerneldir/build/
	    cp -a --parents arch/x86/purgatory/string.c $kerneldir/build/
	    cp -a --parents arch/x86/purgatory/setup-x86_64.S $kerneldir/build/
	    cp -a --parents arch/x86/purgatory/entry64.S $kerneldir/build/
	    cp -a --parents arch/x86/boot/string.h $kerneldir/build/
	    cp -a --parents arch/x86/boot/string.c $kerneldir/build/
	    cp -a --parents arch/x86/boot/ctype.h $kerneldir/build/
	fi

	if [ "${ARCH}" = "mips" ]; then
	    cp -a --parents arch/mips/Kbuild.platforms $kerneldir/build/
	    cp --parents $(find	 -type f -name "Platform") $kerneldir/build
	    cp --parents arch/mips/boot/tools/relocs* $kerneldir/build
	    cp -a --parents arch/mips/kernel/asm-offsets.c $kerneldir/build
	    cp -a --parents kernel/time/timeconst.bc $kerneldir/build
	    cp -a --parents kernel/bounds.c $kerneldir/build
	    cp -a --parents Kbuild $kerneldir/build
	    cp -a --parents arch/mips/kernel/syscalls/*.sh $kerneldir/build 2>/dev/null || :
	    cp -a --parents arch/mips/kernel/syscalls/*.tbl $kerneldir/build 2>/dev/null || :
	    cp -a --parents arch/mips/tools/elf-entry.c $kerneldir/build 2>/dev/null || :
	fi

        # required to build scripts/selinux/genheaders/genheaders
        cp -a --parents security/selinux/include/* $kerneldir/build/
    )

    # Make sure the Makefile and version.h have a matching timestamp so that
    # external modules can be built
    touch -r $kerneldir/build/Makefile $kerneldir/build/include/generated/uapi/linux/version.h

    # Copy .config to include/config/auto.conf so "make prepare" is unnecessary.
    cp $kerneldir/build/.config $kerneldir/build/include/config/auto.conf

    chown -R root:root ${D}
}

# Ensure we don't race against "make scripts" during cpio
do_install[lockfiles] = "${TMPDIR}/kernel-scripts.lock"

FILES_${PN} = "${KERNEL_BUILD_ROOT} ${KERNEL_SRC_PATH}"
FILES_${PN}-dbg += "${KERNEL_BUILD_ROOT}*/build/scripts/*/.debug/*"

RDEPENDS_${PN} = "bc python flex bison ${TCLIBC}-utils"
# 4.15+ needs these next two RDEPENDS
RDEPENDS_${PN} += "openssl-dev util-linux"
# and x86 needs a bit more for 4.15+
RDEPENDS_${PN} += "${@bb.utils.contains('ARCH', 'x86', 'elfutils', '', d)}"