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Diffstat (limited to 'eclass/dist-kernel-utils.eclass')
| -rw-r--r-- | eclass/dist-kernel-utils.eclass | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/eclass/dist-kernel-utils.eclass b/eclass/dist-kernel-utils.eclass new file mode 100644 index 000000000000..9ab65b097b32 --- /dev/null +++ b/eclass/dist-kernel-utils.eclass @@ -0,0 +1,161 @@ +# Copyright 2020-2021 Gentoo Authors +# Distributed under the terms of the GNU General Public License v2 + +# @ECLASS: dist-kernel-utils.eclass +# @MAINTAINER: +# Distribution Kernel Project <dist-kernel@gentoo.org> +# @AUTHOR: +# Michał Górny <mgorny@gentoo.org> +# @SUPPORTED_EAPIS: 7 +# @BLURB: Utility functions related to Distribution Kernels +# @DESCRIPTION: +# This eclass provides various utility functions related to Distribution +# Kernels. + +if [[ ! ${_DIST_KERNEL_UTILS} ]]; then + +case "${EAPI:-0}" in + 0|1|2|3|4|5|6) + die "Unsupported EAPI=${EAPI:-0} (too old) for ${ECLASS}" + ;; + 7) + ;; + *) + die "Unsupported EAPI=${EAPI} (unknown) for ${ECLASS}" + ;; +esac + +# @FUNCTION: dist-kernel_build_initramfs +# @USAGE: <output> <version> +# @DESCRIPTION: +# Build an initramfs for the kernel. <output> specifies the absolute +# path where initramfs will be created, while <version> specifies +# the kernel version, used to find modules. +# +# Note: while this function uses dracut at the moment, other initramfs +# variants may be supported in the future. +dist-kernel_build_initramfs() { + debug-print-function ${FUNCNAME} "${@}" + + [[ ${#} -eq 2 ]] || die "${FUNCNAME}: invalid arguments" + local output=${1} + local version=${2} + + local rel_image_path=$(dist-kernel_get_image_path) + local image=${output%/*}/${rel_image_path##*/} + + local args=( + --force + # if uefi=yes is used, dracut needs to locate the kernel image + --kernel-image "${image}" + + # positional arguments + "${output}" "${version}" + ) + + ebegin "Building initramfs via dracut" + dracut "${args[@]}" + eend ${?} || die -n "Building initramfs failed" +} + +# @FUNCTION: dist-kernel_get_image_path +# @DESCRIPTION: +# Get relative kernel image path specific to the current ${ARCH}. +dist-kernel_get_image_path() { + case ${ARCH} in + amd64|x86) + echo arch/x86/boot/bzImage + ;; + arm64) + echo arch/arm64/boot/Image.gz + ;; + arm) + echo arch/arm/boot/zImage + ;; + ppc64) + # ./ is required because of ${image_path%/*} + # substitutions in the code + echo ./vmlinux + ;; + *) + die "${FUNCNAME}: unsupported ARCH=${ARCH}" + ;; + esac +} + +# @FUNCTION: dist-kernel_install_kernel +# @USAGE: <version> <image> <system.map> +# @DESCRIPTION: +# Install kernel using installkernel tool. <version> specifies +# the kernel version, <image> full path to the image, <system.map> +# full path to System.map. +dist-kernel_install_kernel() { + debug-print-function ${FUNCNAME} "${@}" + + [[ ${#} -eq 3 ]] || die "${FUNCNAME}: invalid arguments" + local version=${1} + local image=${2} + local map=${3} + + # if dracut is used in uefi=yes mode, initrd will actually + # be a combined kernel+initramfs UEFI executable. we can easily + # recognize it by PE magic (vs cpio for a regular initramfs) + local initrd=${image%/*}/initrd + local magic + [[ -s ${initrd} ]] && read -n 2 magic < "${initrd}" + if [[ ${magic} == MZ ]]; then + einfo "Combined UEFI kernel+initramfs executable found" + # install the combined executable in place of kernel + image=${initrd}.uefi + mv "${initrd}" "${image}" || die + # put an empty file in place of initrd. installing a duplicate + # file would waste disk space, and removing it entirely provokes + # kernel-install to regenerate it via dracut. + > "${initrd}" + fi + + ebegin "Installing the kernel via installkernel" + # note: .config is taken relatively to System.map; + # initrd relatively to bzImage + installkernel "${version}" "${image}" "${map}" + eend ${?} || die -n "Installing the kernel failed" +} + +# @FUNCTION: dist-kernel_reinstall_initramfs +# @USAGE: <kv-dir> <kv-full> +# @DESCRIPTION: +# Rebuild and install initramfs for the specified dist-kernel. +# <kv-dir> is the kernel source directory (${KV_DIR} from linux-info), +# while <kv-full> is the full kernel version (${KV_FULL}). +# The function will determine whether <kernel-dir> is actually +# a dist-kernel, and whether initramfs was used. +# +# This function is to be used in pkg_postinst() of ebuilds installing +# kernel modules that are included in the initramfs. +dist-kernel_reinstall_initramfs() { + debug-print-function ${FUNCNAME} "${@}" + + [[ ${#} -eq 2 ]] || die "${FUNCNAME}: invalid arguments" + local kernel_dir=${1} + local ver=${2} + + local image_path=${kernel_dir}/$(dist-kernel_get_image_path) + local initramfs_path=${image_path%/*}/initrd + if [[ ! -f ${image_path} ]]; then + eerror "Kernel install missing, image not found:" + eerror " ${image_path}" + eerror "Initramfs will not be updated. Please reinstall your kernel." + return + fi + if [[ ! -f ${initramfs_path} ]]; then + einfo "No initramfs found at ${initramfs_path}" + return + fi + + dist-kernel_build_initramfs "${initramfs_path}" "${ver}" + dist-kernel_install_kernel "${ver}" "${image_path}" \ + "${kernel_dir}/System.map" +} + +_DIST_KERNEL_UTILS=1 +fi |