summaryrefslogtreecommitdiff
path: root/eclass/dist-kernel-utils.eclass
blob: 67cb802151b20b7380b147dd04789f1d5236ccf2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
# Copyright 2020-2023 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 8
# @BLURB: Utility functions related to Distribution Kernels
# @DESCRIPTION:
# This eclass provides various utility functions related to Distribution
# Kernels.

# @ECLASS_VARIABLE: KERNEL_IUSE_SECUREBOOT
# @PRE_INHERIT
# @DEFAULT_UNSET
# @DESCRIPTION:
# If set to a non-null value, inherits secureboot.eclass
# and allows signing of generated kernel images.

# @ECLASS_VARIABLE: KERNEL_EFI_ZBOOT
# @DEFAULT_UNSET
# @DESCRIPTION:
# If set to a non-null value, it is assumed the kernel was built with
# CONFIG_EFI_ZBOOT enabled. This effects the name of the kernel image on
# arm64 and riscv. Mainly useful for sys-kernel/gentoo-kernel-bin.

if [[ ! ${_DIST_KERNEL_UTILS} ]]; then

case ${EAPI} in
	7|8) ;;
	*) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;;
esac

inherit toolchain-funcs

if [[ ${KERNEL_IUSE_SECUREBOOT} ]]; then
	inherit secureboot
fi

# @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|riscv)
			if [[ ${KERNEL_EFI_ZBOOT} ]]; then
				echo arch/${ARCH}/boot/vmlinuz.efi
			else
				echo arch/${ARCH}/boot/Image.gz
			fi
			;;
		loong)
			if [[ ${KERNEL_EFI_ZBOOT} ]]; then
				echo arch/loongarch/boot/vmlinuz.efi
			else
				echo arch/loongarch/boot/vmlinux.elf
			fi
			;;
		arm)
			echo arch/arm/boot/zImage
			;;
		hppa|ppc|ppc64|sparc)
			# https://www.kernel.org/doc/html/latest/powerpc/bootwrapper.html
			# ./ 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 has_version "<=sys-kernel/installkernel-gentoo-7"; then
		# 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%/*}/uki.efi
			mv "${initrd}" "${image}" || die

			if [[ ${KERNEL_IUSE_SECUREBOOT} ]]; then
				# Ensure the uki is signed if dracut hasn't already done so.
				secureboot_sign_efi_file "${image}"
			fi
		fi
	fi

	ebegin "Installing the kernel via installkernel"
	# note: .config is taken relatively to System.map;
	# initrd relatively to bzImage
	ARCH=$(tc-arch-kernel) installkernel "${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.
#
# With sys-kernel/installkernel-systemd, or version 8 or greater of
# sys-kernel/installkernel-gentoo, the generation of the initrd via dracut
# is handled by kernel-install instead.
#
# 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)
	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 has_version "<=sys-kernel/installkernel-gentoo-7"; then
		local initramfs_path=${image_path%/*}/initrd
		if [[ ! -f ${initramfs_path} && ! -f ${initramfs_path%/*}/uki.efi ]]; then
			einfo "No initramfs or uki found at ${image_path}"
			return
		fi

		dist-kernel_build_initramfs "${initramfs_path}" "${ver}"
	fi

	dist-kernel_install_kernel "${ver}" "${image_path}" \
		"${kernel_dir}/System.map"
}

# @FUNCTION: dist-kernel_PV_to_KV
# @USAGE: <pv>
# @DESCRIPTION:
# Convert a Gentoo-style ebuild version to kernel "x.y.z[-rcN]" version.
dist-kernel_PV_to_KV() {
	debug-print-function ${FUNCNAME} "${@}"

	[[ ${#} -ne 1 ]] && die "${FUNCNAME}: invalid arguments"
	local pv=${1}

	local kv=${pv%%_*}
	[[ -z $(ver_cut 3- "${kv}") ]] && kv+=".0"
	[[ ${pv} == *_* ]] && kv+=-${pv#*_}
	echo "${kv}"
}

_DIST_KERNEL_UTILS=1
fi