Hello everyone,
I try to explore linux and specially his kernel. I have succeed to compile a regular kernel and to remove a lot of unnecessary features. I am to the point where I have even transform all modules into a built-in features.
So my plan is to build a module-less or monolithic kernel.
When i searched how to do it i was surprised to see very little topic on the subject the only one i found in gentoo was extremly short (5 lines no more).
My issue is to succeed to compile a complete kernel. With menu makeconfig i have disable modules and after failing with this message :
***
*** The present kernel configuration has modules disabled.
*** To use the module feature, please run "make menuconfig" etc.
*** to enable CONFIG_MODULES.
***
make: *** [Makefile:1771 : modules_install] Erreur 1
I create a patch to allow me to proceed.
So there is my actual files :
my patch "moduleless.patch" :
##
## Allowing a moduleless kernel. Made for kernel 6.0.3
##
diff --unified --recursive --text --color a/include/config/auto.conf b/include/config/auto.conf
--- a/include/config/auto.conf
+++ b/include/config/auto.conf
@@ -213,7 +213,6 @@
CONFIG_USB=y
CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK=y
CONFIG_ACPI_PCI_SLOT=y
-CONFIG_MODULES_USE_ELF_RELA=y
CONFIG_CRYPTO_HMAC=y
CONFIG_UBSAN_ARRAY_BOUNDS=y
CONFIG_WLAN_VENDOR_REALTEK=y
@@ -1647,7 +1646,6 @@
CONFIG_KVM_XFER_TO_GUEST_WORK=y
CONFIG_SERIAL_8250_PERICOM=y
CONFIG_SERIAL_8250_NR_UARTS=32
-CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
CONFIG_CPU_SUP_HYGON=y
CONFIG_DMA_OPS=y
CONFIG_NET_EGRESS=y
diff --unified --recursive --text --color a/Makefile b/Makefile
--- a/Makefile
+++ b/Makefile
@@ -2,8 +2,8 @@
VERSION = 6
PATCHLEVEL = 0
SUBLEVEL = 3
-EXTRAVERSION =
-NAME = Hurr durr I'ma ninja sloth
+EXTRAVERSION = custom
+NAME = Hurr durr I'm a crazy ninja sloth
# *DOCUMENTATION*
# To see a list of typical targets execute "make help"
@@ -648,7 +648,7 @@
# Decide whether to build built-in, modular, or both.
# Normally, just do built-in.
-KBUILD_MODULES :=
+KBUILD_MODULES := 0
KBUILD_BUILTIN := 1
# If we have only "make modules", don't compile built-in objects.
@@ -661,11 +661,11 @@
# Just "make" or "make all" shall build modules as well
ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
- KBUILD_MODULES := 1
+ KBUILD_MODULES := 0
endif
ifeq ($(MAKECMDGOALS),)
- KBUILD_MODULES := 1
+ KBUILD_MODULES := 0
endif
export KBUILD_MODULES KBUILD_BUILTIN
@@ -1142,7 +1142,7 @@
# For the kernel to actually contain only the needed exported symbols,
# we have to build modules as well to determine what those symbols are.
# (this can be evaluated only once include/config/auto.conf has been included)
-KBUILD_MODULES := 1
+KBUILD_MODULES := 0
autoksyms_recursive: descend modules.order
$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
@@ -1716,8 +1716,8 @@
# in the basis kernel ordinary make commands (without M=...) must be used.
# We are always building only modules.
-KBUILD_BUILTIN :=
-KBUILD_MODULES := 1
+KBUILD_BUILTIN := 1
+KBUILD_MODULES := 0
build-dirs := $(KBUILD_EXTMOD)
$(MODORDER): descend
@@ -1788,7 +1788,7 @@
@echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
@echo >&2 '*** to enable CONFIG_MODULES.'
@echo >&2 '***'
- @exit 1
+ @exit 0
endif # CONFIG_MODULES
@@ -1827,7 +1827,7 @@
$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
-KBUILD_MODULES := 1
+KBUILD_MODULES := 0
export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko))
@@ -1838,7 +1838,7 @@
endif
ifndef CONFIG_MODULES
-KBUILD_MODULES :=
+KBUILD_MODULES := 0
endif
# Handle descending into subdirectories listed in $(build-dirs)
and my pkgbuild :
pkgbase=linux-custom
pkgver=6.0.3
pkgrel=3
pkgdesc='Linux kernel and modules'
url="https://www.kernel.org/"
arch=(x86_64)
license=(GPL2)
makedepends=(
bc kmod libelf pahole cpio perl tar xz
xmlto graphviz imagemagick cpio
)
options=('!strip')
_srcname=linux-$pkgver
source=(
https://cdn.kernel.org/pub/linux/kernel/v${pkgver%%.*}.x/${_srcname}.tar.{xz,sign}
config # the main kernel config file
0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-C.patch
0003-iommu_intel_do_deep_dma-unmapping_to_avoid_kernel-flooding.patch
moduleless.patch
)
validpgpkeys=(
'ABAF11C65A2970B130ABE3C479BE3E4300411886' # Linus Torvalds
'647F28654894E3BD457199BE38DBBDC86092693E' # Greg Kroah-Hartman
)
# https://www.kernel.org/pub/linux/kernel/v5.x/sha256sums.asc
sha256sums=('b0d522241805794d8af3a67d331ba063a16496c6fb6d365d48f7ed78ee1c3dcf'
'SKIP'
'8dd9236334113c523007a237f6db93ea167b4c074c2be8ef733d027db6db584a'
'17b9a8c2d0c02a8841c4b8d94a6ba0c8323e404bad19c71903a1ad665a25b1be'
'864f299d3d990c98e1cc088d3a27661ae998ca2801cb025fa3dcdcdf5713e8ce'
'fbd5e9dc23e74aead48b95e9819a49a9e05e9593c2375594e1eeb4c05001fba1')
export KBUILD_BUILD_HOST=artixlinux
export KBUILD_BUILD_USER=$pkgbase
export KBUILD_BUILD_TIMESTAMP="$(date -Ru${SOURCE_DATE_EPOCH:+d @$SOURCE_DATE_EPOCH})"
prepare() {
cd $_srcname
echo "Setting config..."
cp ../config .config
make menuconfig && make prepare
# diff -u ../config .config || :
echo "Setting version..."
scripts/setlocalversion --save-scmversion
echo "-$pkgrel" > localversion.10-pkgrel
echo "${pkgbase#linux}" > localversion.20-pkgname
local src
for src in "${source[@]}"; do
src="${src%%::*}"
src="${src##*/}"
[[ $src = *.patch ]] || continue
echo "Applying patch $src..."
patch -Np1 < "../$src"
done
#return 1
make -s kernelrelease > version
echo "Prepared $pkgbase version $(<version)"
}
build() {
cd $_srcname
make
make install
}
_package() {
pkgdesc="The $pkgdesc kernel and modules"
depends=(coreutils kmod initramfs)
optdepends=('crda: to set the correct wireless channels of your country'
'linux-firmware: firmware images needed for some devices')
provides=(VIRTUALBOX-GUEST-MODULES WIREGUARD-MODULE)
replaces=(wireguard)
cd $_srcname
local kernver="$(<version)"
local modulesdir="$pkgdir/usr/lib/modules/$kernver"
echo "Installing boot image..."
# systemd expects to find the kernel here to allow hibernation
# https://github.com/systemd/systemd/commit/edda44605f06a41fb86b7ab8128dcf99161d2344
install -Dm644 "$(make -s image_name)" "$modulesdir/vmlinuz"
# Used by mkinitcpio to name the kernel
echo "$pkgbase" | install -Dm644 /dev/stdin "$modulesdir/pkgbase"
}
_package-headers() {
pkgdesc="Headers and scripts for building modules for the $pkgdesc kernel"
depends=(pahole)
cd $_srcname
local builddir="$pkgdir/usr/lib/modules/$(<version)/build"
echo "Installing build files..."
install -Dt "$builddir" -m644 .config Makefile System.map \
localversion.* version vmlinux
install -Dt "$builddir/kernel" -m644 kernel/Makefile
install -Dt "$builddir/arch/x86" -m644 arch/x86/Makefile
cp -t "$builddir" -a scripts
# add objtool for external module building and enabled STACK_VALIDATION option
install -Dt "$builddir/tools/objtool" tools/objtool/objtool
# add xfs and shmem for aufs building
mkdir -p "$builddir"/{fs/xfs,mm}
echo "Installing headers..."
cp -t "$builddir" -a include
cp -t "$builddir/arch/x86" -a arch/x86/include
install -Dt "$builddir/arch/x86/kernel" -m644 arch/x86/kernel/asm-offsets.s
install -Dt "$builddir/drivers/md" -m644 drivers/md/*.h
install -Dt "$builddir/net/mac80211" -m644 net/mac80211/*.h
# https://bugs.archlinux.org/task/13146
install -Dt "$builddir/drivers/media/i2c" -m644 drivers/media/i2c/msp3400-driver.h
# https://bugs.archlinux.org/task/20402
install -Dt "$builddir/drivers/media/usb/dvb-usb" -m644 drivers/media/usb/dvb-usb/*.h
install -Dt "$builddir/drivers/media/dvb-frontends" -m644 drivers/media/dvb-frontends/*.h
install -Dt "$builddir/drivers/media/tuners" -m644 drivers/media/tuners/*.h
# https://bugs.archlinux.org/task/71392
install -Dt "$builddir/drivers/iio/common/hid-sensors" -m644 drivers/iio/common/hid-sensors/*.h
echo "Installing KConfig files..."
find . -name 'Kconfig*' -exec install -Dm644 {} "$builddir/{}" \;
echo "Removing unneeded architectures..."
local arch
for arch in "$builddir"/arch/*/; do
[[ $arch = */x86/ ]] && continue
echo "Removing $(basename "$arch")"
rm -r "$arch"
done
echo "Removing documentation..."
rm -r "$builddir/Documentation"
echo "Removing broken symlinks..."
find -L "$builddir" -type l -printf 'Removing %P\n' -delete
echo "Removing loose objects..."
find "$builddir" -type f -name '*.o' -printf 'Removing %P\n' -delete
echo "Stripping build tools..."
local file
while read -rd '' file; do
case "$(file -bi "$file")" in
application/x-sharedlib\;*) # Libraries (.so)
strip -v $STRIP_SHARED "$file" ;;
application/x-archive\;*) # Libraries (.a)
strip -v $STRIP_STATIC "$file" ;;
application/x-executable\;*) # Binaries
strip -v $STRIP_BINARIES "$file" ;;
application/x-pie-executable\;*) # Relocatable binaries
strip -v $STRIP_SHARED "$file" ;;
esac
done < <(find "$builddir" -type f -perm -u+x ! -name vmlinux -print0)
echo "Stripping vmlinux..."
strip -v $STRIP_STATIC "$builddir/vmlinux"
echo "Adding symlink..."
mkdir -p "$pkgdir/usr/src"
ln -sr "$builddir" "$pkgdir/usr/src/$pkgbase"
}
pkgname=("$pkgbase" "$pkgbase-headers" )
for _p in "${pkgname[@]}"; do
eval "package_$_p() {
$(declare -f "_package${_p#$pkgbase}")
_package${_p#$pkgbase}
}"
done
When i compile i have this warning who is more than a warning because my network is now a mess ... I am clearly not an expert but i'd like to learn so i may have make obvious mistakes.
==> WARNING: No modules were added to the image. This is probably not what you want.
==> Creating zstd-compressed initcpio image: /boot/initramfs-linux-Custs-fallback.img
==> WARNING: errors were encountered during the build. The image may not be complete.
What am i missing ?
Topic: Buildig a module-less kernel (Read 782 times)
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