building xen dom0 linux kernel

requirements

manually

cd /usr/src/
screen -S kernel-build

ver=5.18.19

it’s good to define a custom name in view to have different flavor for the very same version – otherwise /lib/modules/THAT-ONE/ conflicts with the OTHER-ONE.

extra=xen-ufs-usb
extra=nethence

grab the version you want e.g. here for being able to patch with hba mode we want 5.18

wget https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-$ver.tar.gz
time tar xzf linux-$ver.tar.gz

and also eventually apply the latest available REISER4 patch

wget https://sourceforge.net/projects/reiser4/files/reiser4-for-linux-5.x/reiser4-for-5.16.patch.gz

mv linux-$ver/ linux-$ver.$extra/
cd linux-$ver.$extra/

eventually apply the REISER4 patch

patch -p1 < ../reiser4-for-5.16.patch

clean-up in case you had previous builds

make mrproper

get a fresh copy slackware huge kernel config (loads of drivers built-in)

wget https://lab.nethence.com/confdiff/config-huge.clean.txt
cp -f config-huge.clean.txt .config
make olddefconfig

mv -i Makefile Makefile.dist
sed "s/^EXTRAVERSION =/EXTRAVERSION = .$extra/" Makefile.dist > Makefile
diff -u Makefile.dist Makefile

proceed with adding the drivers you need e.g.

make xen.config

# preview
sed -nr 's/^(CONFIG_USB_STORAGE.*)=m/\1=y/p'

# change config
sed -ri 's/^(CONFIG_USB_STORAGE.*)=m/\1=y/' .config

cat >> .config <<EOF
CONFIG_UFS_FS=y
CONFIG_UFS_FS_WRITE=y
CONFIG_USB_UHCI_HCD=y
CONFIG_USB_EHCI_HCD=y
CONFIG_USB_XHCI_HCD=y
CONFIG_X86_X32=n
EOF
make olddefconfig

grep -vE '^#' .config | sort -V > .config.clean
diff -u config-huge.clean.txt .config.clean
echo $MAKEFLAGS
time make > ../linux-$ver.$extra.log && echo BUILT

ls -ldF /lib/modules/$ver.$extra/
rm -rf /lib/modules/$ver.$extra/
time make modules_install >/dev/null && echo MODULES INSTALLED

and if you need to run that kernel on that very same machine where you built it from

cp -fv arch/x86/boot/bzImage /$ver.$extra.config
cp -fv arch/x86/boot/bzImage /$ver.$extra.vmlinuz
ln -svf $ver.$extra.vmlinuz /vmlinuz

otherwise I usually pack it up as such

mkdir -p /data/kernels/
cp -fv arch/x86/boot/bzImage /data/kernels/$ver.$extra.vmlinuz
cp -fv .config /data/kernels/$ver.$extra.config
time tar -C /lib/modules/ -I 'zstd -T0' -cf /data/kernels/$ver.$extra.modules.tar.zstd $ver.$extra/
time tar -C /usr/src/ -I 'zstd -T0' -cf /data/kernels/$ver.$extra.source.tar.zstd linux-$ver.$extra/

dummy benchmark results

real    23m46.416s
user    671m12.823s
sys 61m14.924s

# tar modules
real    0m18.271s
user    0m5.201s

# tar source
sys 0m1.875s
real    0m7.675s
user    0m47.714s
sys 0m13.131s

scripted

ver=...
config=...

wget https://pub.nethence.com/bin/xen/build0.bash
chmod +x build0.bash
./build0.bash linux-$ver $config
#./build0.bash linux-5.16.20.tar config.txt reiser4-for-5.16.patch.gz

resources

building xen dom0 linux kernel

requirements

manually

dummy benchmark results

scripted

resources

xen

kernel config

docker

build on debian/ubuntu