[linux_distributions][chromium_os] How to build a custom Termina virtual machine

[LukeShortCloud]

• ARCHITECTURE = https://chromium.googlesource.com/chromiumos/docs/+/1ec7c3500b6fccf85536c3fd70bc538f517cd3b4/crostini_developer_guide.md and https://chromium.googlesource.com/chromiumos/platform/crosvm/+/837b59f2d97b005ef84ac36efa97530c1bbf2a79/README.md
• Hypervisor requirements: https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/main/chromeos-base/vm_host_tools/
  • Minimium/required = crosvm
  • Optional = minijail
• Minimum requirements:
  • Setup two users: root and chronos
    • Both users need PAM to allow passwordless login
  • Serial console enabled
  • Packages: bzip2, gzip, ta, xz-utils, mcastd, minijail, ndproxyd, vm_guest_tools, iproute2, pambase https://chromium.googlesource.com/chromiumos/overlays/board-overlays/+/main/project-termina/virtual/target-termina-os/target-termina-os-1.5.ebuild
  • vshd (NOTE: it only allows a user to log in as the chronos user) https://chromium.googlesource.com/chromiumos/platform2/+/HEAD/vm_tools/vsh
• Full requirements:
  • termina-lxd-scripts added https://chromium.googlesource.com/chromiumos/overlays/board-overlays/+/main/project-termina/chromeos-base/termina-lxd-scripts/
  • /etc/arc_host.conf = Additional hosts file for LXD containers https://chromium.googlesource.com/chromiumos/platform/tremplin/+/a544e492c07e50ba34bb4e5da0cbf0d660173b78/src/chromiumos/tremplin/start_lxd.go#76 and https://chromium.googlesource.com/chromiumos/overlays/board-overlays/+/main/project-termina/chromeos-base/chromeos-bsp-termina/files/arc_host.conf
  • Optional developer tools: https://chromium.googlesource.com/chromiumos/overlays/board-overlays/+/main/project-termina/virtual/target-termina-os-dev/target-termina-os-dev-1.5.ebuild
  • Optional tools used by tests: https://chromium.googlesource.com/chromiumos/overlays/board-overlays/+/main/project-termina/virtual/target-termina-os-test/target-termina-os-test-1.5.ebuild

Originally posted by @LukeShortCloud in https://github.com/LukeShortCloud/rootpages/issues/621#issuecomment-1001742838

[LukeShortCloud]

Currently I am testing an Arch Linux installation with these packages (along with yay):

$ sudo pacstracp -i ./arch-install base base-devel git vim

[LukeShortCloud]

These steps are confirmed to be working for a minimal crosvm without GUI access or any integration:

truncate -s 20G termina.ext4
mkfs.ext4 termina.ext4
mkdir rootfs
sudo mount termina.ext4 rootfs/

sudo pacstrap -i ./rootfs/ base base-devel bzip2 git gzip iproute2 vim xz
echo "tmpfs /tmp tmpfs defaults 0 0" | sudo tee -a rootfs/etc/fstab
echo "tmpfs /var/log tmpfs defaults 0 0" | sudo tee -a  rootfs/etc/fstab
echo "tmpfs /root tmpfs defaults 0 0" | sudo tee -a rootfs/etc/fstab
echo "sysfs /sys sysfs defaults 0 0" | sudo tee -a rootfs/etc/fstab 
echo "proc /proc proc defaults 0 0" | sudo tee -a rootfs/etc/fstab
sudo chroot rootfs/
    [root@localhost /]# passwd root
    [root@localhost /]# exit
umount ./rootfs
git clone --depth 1 -b chromeos-5.15 https://chromium.googlesource.com/chromiumos/third_party/kernel kernel-chromeos-5.15
cd kernel-chromeos-5.15
make chromiumos-container-vm-x86_64_defconfig
make -j $(nproc) bzImage
cp arch/x86/boot/bzImage ../bzImage-chromeos-5.15
crosvm run --disable-sandbox --rwroot "$(pwd)/termina.ext4" --rwdisk "$(pwd)/disk.img" -p init=/bin/bash bzImage-chromeos-5.15

https://google.github.io/crosvm/running_crosvm/basic_usage.html