kernel-devsrc: restructure for out of tree (and on target) module builds

The existing kernel-devsrc package starts with a full copy of the kernel
source and then starts to strip out elements that are not required.

This results in extra time (I/O) and extra space being taken up in the
final package. The main purpose of the kernel-devsrc package has been to
build modules against the running kernel, not to include a full copy of
the source code for re-building the kernel. The end result was a
600M kernel-devsrc package.

This restructuring of the package uses an approach similar to other
distros, where the kernel-devsrc package is for building against the
running kernel and uses a curated set of copied infrastructure, versus
a mass copy of the entire kernel.

The differences in this approach versus other is largely due to the
architecture support and the split build/source directory of the
kernel.

The result is a kernel-devsrc package of about 10M, which is capable
of running "make scripts" and compiling kernel modules against the
running kernel.

Along with the changes to the copying of the infrascture, we also
have the following changes:

 - a better/more explicit listing of dependencies for on-target
   builds of "make scripts" or "make modules_prepare"

 - The kernel source is installed into /lib/modules/<version>/build
   and a symlink created from /usr/src/kernel to the new location.
   This aligns with the standard location for module support
   code

 - There is also a symlink from /lib/modules/<version>/source -> build
   to reserve a spot for a new package that is simply the kernel
   source. That package is not part of this update.

(From OE-Core rev: 007ef1f468110b2698a27ea9a6d43fed5a0a9fc2)

Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
This commit is contained in:
Bruce Ashfield
2018-08-18 22:50:44 -04:00
committed by Richard Purdie
parent 47a73c5228
commit 9af0f1a46b
3 changed files with 192 additions and 45 deletions

View File

@@ -30,57 +30,202 @@ do_populate_sysroot[noexec] = "1"
S = "${STAGING_KERNEL_DIR}"
B = "${STAGING_KERNEL_BUILDDIR}"
KERNEL_VERSION = "${@get_kernelversion_headers('${S}')}"
PACKAGE_ARCH = "${MACHINE_ARCH}"
KERNEL_BUILD_ROOT="/lib/modules/"
do_install() {
kerneldir=${D}${KERNEL_SRC_PATH}
install -d $kerneldir
kerneldir=${D}${KERNEL_BUILD_ROOT}${KERNEL_VERSION}
install -d $kerneldir
#
# Copy the staging dir source (and module build support) into the devsrc structure.
# We can keep this copy simple and take everything, since a we'll clean up any build
# artifacts afterwards, and the extra i/o is not significant
#
cd ${B}
find . -type d -name '.git*' -prune -o -path '.debug' -prune -o -type f -print0 | cpio --null -pdlu $kerneldir
cd ${S}
find . -type d -name '.git*' -prune -o -type d -name '.kernel-meta' -prune -o -type f -print0 | cpio --null -pdlu $kerneldir
# create the directory structure
rm -f $kerneldir/build
rm -f $kerneldir/source
mkdir -p $kerneldir/build
# Explicitly set KBUILD_OUTPUT to ensure that the image directory is cleaned and not
# The main build artifacts. We clean the directory to avoid QA errors on mismatched
# architecture (since scripts and helpers are native format).
KBUILD_OUTPUT="$kerneldir"
oe_runmake -C $kerneldir CC="${KERNEL_CC}" LD="${KERNEL_LD}" clean _mrproper_scripts
# make clean generates an absolute path symlink called "source"
# in $kerneldir points to $kerneldir, which doesn't make any
# sense, so remove it.
if [ -L $kerneldir/source ]; then
bbnote "Removing $kerneldir/source symlink"
rm -f $kerneldir/source
fi
# 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
ln -s ${KERNEL_BUILD_ROOT}${KERNEL_VERSION}/source kernel
)
# As of Linux kernel version 3.0.1, the clean target removes
# arch/powerpc/lib/crtsavres.o which is present in
# KBUILD_LDFLAGS_MODULE, making it required to build external modules.
if [ ${ARCH} = "powerpc" ]; then
mkdir -p $kerneldir/arch/powerpc/lib/
cp ${B}/arch/powerpc/lib/crtsavres.o $kerneldir/arch/powerpc/lib/crtsavres.o
fi
# for on target purposes, we unify build and source
(
cd $kerneldir
ln -s build source
)
# Remove fixdep/objtool as they won't be target binaries
for i in fixdep objtool; do
if [ -e $kerneldir/tools/objtool/$i ]; then
rm -rf $kerneldir/tools/objtool/$i
fi
done
# 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
)
chown -R root:root ${D}
# 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 $kerneldir/build/
fi
# include the machine specific headers for ARM variants, if available.
if [ "${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/
cp -a --parents arch/arm/tools/syscall* $kerneldir/build/
fi
if [ -d arch/${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
fi
)
# 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"
PACKAGES = "kernel-devsrc"
FILES_${PN} = "${KERNEL_SRC_PATH}"
RDEPENDS_${PN} = "bc"
FILES_${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)}"