Gentoo setup2 - hpaluch/hpaluch.github.io GitHub Wiki

Gentoo setup2

Here are my terse instructions for Gentoo setup. I plan to install Gentoo onto SATA disk attached via USB to very fast computer Cubi and later boot same disk on my slower computers (ZotacNano or even dual-Opteron machine).

I always use this profile:

  • OpenRC (no systemd allowed)
  • Desktop X11 with CTWM Window Manager (used on NetBSD - like old fvwm). Why CTWM - because even Xfce and/or LXDE will not start without D-Bus. And why not NetBSD? Because its Hyperivsor is lacking important features when compared to KVM (PCI passthrough, nested virtualizaiton,...).

Generally I follow:

I currently use Desktop+OpenRC. Typically I look to this mirror for Stage3 tarball:

So first we have to download install ISO.

I will start with VM (virt-manager), but I will attach SATA disk via USB

  • host device is /dev/sdb
  • when adding disk in virt-manager I will simply specify /dev/sdb as image path (yes, that easy).

I will simply boot from ISO - network should work automatically. However I will set root's password and run sshd so I coudl copy&paste commands...

  • simply run passwd to set root's password
  • next start sshd using: /etc/init.d/sshd
  • to get your IP address run ip -br -4 a
  • I usually start log session (on my client PC from whic I will run SSH client) using script gentoo-install.log
  • now you can login to this gentoo server using ssh root@IP

Now I have to prepare partitions and filesystem. I will use hybrid system:

  • GPT with both BIOS and UEFI support (because I plan to use that disk on 3 machines, 2 have UEFI and 1 have BIOS only)
  • ensure that fdisk uses gpt
  • so I did:
fdisk /dev/vda # pass-through to USB SATA disk

Here is my final layout:

Disklabel type: gpt

Device         Start       End   Sectors  Size Type
/dev/vda1       2048     10239      8192    4M BIOS boot
/dev/vda2      10240   1058815   1048576  512M EFI System
/dev/vda3    1058816 210774015 209715200  100G Linux filesystem
/dev/vda4  210774016 277882879  67108864   32G Linux swap

Note: it is good idea to have EFI System partition large, because there could be some unexpected events (some distributions are putting whole /boot to EFI etc., or we will have space if ever BIOS boot will need to larger...)

Now we have to format 3 partitions (with the exception of BIOS boot...)

# double check device names!!!
mkfs.vfat -n GEN-EFI /dev/vda2
mkfs.btrfs -L gen-rootfs /dev/vda3
mkswap -L gen-swap /dev/vda4

Now we should activate all formatted filesystems so there will be automatically generated to /etc/fstab later...

swapon /dev/vda4
# below is trickery to use subvolume for rootfs in case of btrfs:
btrfs su cr /mnt/@rootfs
btrfs su cr /mnt/@home
# now mount subvolume @rootfs as /
mount -o compress,subvol=@rootfs /dev/vda3 /mnt/gentoo
# same for subvol @home on /home
mkdir /mnt/gentoo/home
mount -o subvol=@home /dev/vda3 /mnt/gentoo/home
# and finally efi
mkdir /mnt/gentoo/efi
mount /dev/vda2 /mnt/gentoo/efi

Now it is time to download and unpack stage file:

cd /mnt/gentoo
curl -fLO https://ftp.linux.cz/pub/linux/gentoo/releases/amd64/autobuilds/current-stage3-amd64-desktop-openrc/stage3-amd64-desktop-openrc-20250928T160345Z.tar.xz
tar xpvf stage3-*.tar.xz --xattrs-include='*.*' --numeric-owner

Required copies:

cd /mnt/gentoo
mkdir -p etc/portage/repos.conf
cp usr/share/portage/config/repos.conf etc/portage/repos.conf/gentoo.conf
cp -L /etc/resolv.conf etc

Now here is my etc/portage/package.use/custom common for all deployments where I plan to use Wayland with Sway:

# /etc/portage/package.use/custom

# Custom USE flags per app
app-text/ghostscript-gpl -dbus
app-arch/cpio  -nls
app-editors/vim -X -acl -crypt -sound

And here is common part (for both Azure build host and Target) of etc/portage/make.conf

# Do NOT use -fno-strict-aliasing - it breaks glibc!
# see https://bugs.gentoo.org/955635
COMMON_FLAGS="-O2 -pipe"
# other flags keep "as is"
MAKEOPTS="-j8"
USE="vaapi vdpau brotli webp -kde -accessibility -openmp -fortran \
     -qmanifest -imap -pop3 -qtegrity -tftp compress-zstd zstd \
     logrotate kms gles2 vim-syntax lvm lm-sensors contrib \
     layers tray wallpapers -bluetooth -joystick alsa"
VIDEO_CARDS="nouveau intel qxl"
ACCEPT_LICENSE="@FREE @BINARY-REDISTRIBUTABLE"

# It is closest mirror for me - you may need to change it
GENTOO_MIRRORS="http://ftp.fi.muni.cz/pub/linux/gentoo/"

# always build binary packages (useful for example if compiler gets corrupted, etc...)
FEATURES="buildpkg"
# which Binary packages to NOT build:
EMERGE_DEFAULT_OPTS="${EMERGE_DEFAULT_OPTS} --buildpkg-exclude  'acct-*/* sys-kernel/*-sources virtual/*'"

Now we can enter chroot simply with:

arch-chroot /mnt/gentoo
source /etc/profile
PS1="(chroot) $PS1"

Now fetch portage archives

# inside chroot
emerge-webrsync

Here is complete /etc/portage/make.conf from Azure build server chroot:

TODO

Verify that we have proper profile:

$ eselect profile list  | fgrep '*'

  [3]   default/linux/amd64/23.0/desktop (stable) *

Now on build-server we can rebuild world using:

# in chroot of build server
# around 50 packages will be rebuild
emerge --ask --verbose --update --deep --newuse @world
# press 'n'
# foudn all packages that will be rebuild 'R' flag and...

NOTE: To avoid costly rebuilds (due USE flags change) I made small changes - created /etc/portage/package.use/custom with:

# avoid costly rebuilds
app-portage/portage-utils qmanifest
dev-db/sqlite -icu
sys-devel/gcc fortran openmp
llvm-runtimes/clang-runtime openmp
x11-libs/gtk+ -vim-syntax
dev-qt/qtbase -brotli

And rerun:

emerge --ask --verbose --update --deep --newuse @world
# answer 'y' if OK
# in my case I have to install/build 45 packages
# it took

Merging changes in /etc/

Now more setup:

# in chroot:
echo Europe/Prague > /etc/timezone
emerge --config sys-libs/timezone-data

Next:

  • edit chroot file /etc/locale.gen
    • I uncommented only en_US.*
  • inside chroot run locale-gen
  • verify selected locale: eselect locale list
    • I use C.UTF-8 (should be default - with asterisk *)
  • refresh environemnt with: 
    source /etc/profile
PS1="(chroot) $PS1"

Install firmware:

emerge -an sys-kernel/linux-firmware sys-firmware/sof-firmware

Before kernel install grub (because package installkernel will be able to genereate grub config):

# ensure that GRUB_PLATFORM includes: efi-64 pc
emerge -an sys-boot/grub
# install grub (in my case in BIOS mode, so far):
grub-install /dev/vda

Setup and install installkernel:

echo 'sys-kernel/installkernel dracut grub' >> /etc/portage/package.use/custom
emerge -an sys-kernel/installkernel

Installing kernel source:

  • many programs need kernel source in /usr/src):
  • TODO: why it installs xemacs(?) 
    emerge -an sys-kernel/gentoo-sources sys-apps/pciutils sys-kernel/dracut \
  sys-fs/btrfs-progs sys-fs/lvm2
  • select only kernel source (it will create symbolic link /usr/src/linux needed by apps) 
    eselect kernel list
eselect kernel set 1

Generate fstab (required for initramfs/grub that will be run on kernel install):

# OUTSIDE chroot run:
genfstab -U /mnt/gentoo >> /mnt/gentoo/etc/fstab

Building kernel - using config from my project:

# again in chroot:
cd /usr/src
curl -fLO https://github.com/hpaluch/gentoo-files/raw/refs/heads/master/kernels/linux-6.6.30-gentoo/lvefi_defconfig
cp lvefi_defconfig linux/arch/x86/configs
cd linux
make lvefi_defconfig
make menuconfig # finetune details
# build kernel, should also create ramdisk (dracut) and grub entry:
make -j`nproc` && make modules_install && make install

Installing various programs:

emerge -an sys-fs/ncdu app-portage/gentoolkit app-editors/vim app-misc/mc app-admin/sudo \
  app-misc/tmux app-admin/sysstat sys-apps/smartmontools \
  net-misc/dhcpcd app-admin/rsyslog sys-process/cronie app-shells/bash-completion \
  sys-process/lsof

On Target chroot remember to at least set root password:

passwd root

Set proper default editor - create script etc/profile.d/editor.sh with contents:

export EDITOR=/usr/bin/vim

Source it in chroot:

source /etc/profile.d/editor.sh

And do few changes using visudo in chroot:

  • add Defaults !fqdn to avoid DNS lookups on each sudo invocation
  • uncomment %wheel ALL=(ALL:ALL) NOPASSWD: ALL
  • now setup user and add it to wheel group:
# all commands run in Target chroot:
u=YOUR_USERNAME
/usr/sbin/useradd -G wheel -m -s /bin/bash $u
passwd $u

In chroot ensure that neede services will start:

# run in Target chroot
rc-update add dhcpcd default
rc-update add rsyslog default
rc-update add sshd default

X-Window install

It is always usefull to have X-Window as fallback (if Wayland does not work) - we can follow https://wiki.gentoo.org/wiki/Xorg/Guide - I plan to install X-Window + XFCE and use startx to start X-Window and sway to start Wayland.

NOTE this:

  • all my real hardware is NVidia or Intel GPU (no AMD/ATI)
  • I plan to also use Gentoo as VM - so qxl, VMware or VirtualBox guest support is wanted.
  • here are my settings in etc/portage/make.conf 
    INPUT_DEVICES="libinput vmmouse"
VIDEO_CARDS="intel nouveau qxl i915 nvidia vesa virtualbox vmware"
USE=" ... xvfb xa"

WARNING! In case of my old NVidia GT218 there is bad news, looking at

  • https://wiki.gentoo.org/wiki/NVIDIA
  • last driver that supports that card is 340
  • this should help (but not yet tested) - from https://wiki.gentoo.org/wiki/NVIDIA/nvidia-drivers: 
    echo '>x11-drivers/nvidia-drivers-340' >> /etc/portage/package.mask/nvidia-gt218
  • PROBLEM: As of Dec 2023 - oldest nvidia-drivers-X package is x11-drivers/nvidia-drivers-390.157, but my card is supported by 340 only... In such case the only "solution" is to remove "nvidia" from VIDEO_CARDS...

Following: https://wiki.gentoo.org/wiki/Xorg/Guide First we should check if we have correct flags for Driver:

emerge -pv  x11-base/xorg-drivers

When it looks reasonable, building with:

emerge -an x11-base/xorg-server
emerge -an x11-wm/ctwm

echo XSESSION=ctwm > /etc/env.d/90xsession
env-update && source /etc/profile

Additionally I plan to use:

emerge -an  x11-apps/xinit x11-terms/xterm

To start X-Window few requirements must be met:

  • resolvable hostname - ping below must work properly: 
    ping `hostname`
    • otherwise there will be xauth related errors
  • due required X-Server privileges, the elogind must be running in OpenRC environment (my case) 
    rc-update add elogind boot
/etc/init.d/elogind start
    • you need to logout and login, because there is elogind PAM module executed on login
    • otherwise X-server will report permission error when accessing /dev/ttyX When done you can start X-Window using startx command...

If mouse and keyboard does not work we need to follow

  • https://wiki.gentoo.org/wiki/Libinput
  • emerge: 
    emerge -an x11-misc/xdotool x11-misc/wmctrl
  • add your user to input group: 
    usermod -a -G input USERNAME
    • and login again to become member of input group
  • to detect PS/2 mouse I needed to reboot machine - than it worked: 
    libinput list-devices | fgrep -A 1 -i ps/2

Device:           ImPS/2 Generic Wheel Mouse
Kernel:           /dev/input/event15

# Your list will be likely different!
# Answer Yes to make these packages sticky:
emerge -an media-fonts/liberation-fonts x11-apps/xrefresh x11-apps/xrandr
# run again:

Finally we should install QEMU guest agent and SPICE/QXL utilities:

  • I have to manually change card type from Virtio to QXL in virt-manager (some functions not yet work properly with Virtio PV card)
  • install and run QEMU guest agent: 
    emerge -an app-emulation/qemu-guest-agent
rc-update add qemu-guest-agent default
  • and SPICE VDA agent: 
    emerge -an app-emulation/spice-vdagent
rc-update add spice-vdagent default
  • reboot system to ensure that all changes will be propagated