patches and low-level development discussion

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 #!/bin/execlineb -W
# SPDX-License-Identifier: EUPL-1.2+
# SPDX-FileCopyrightText: 2024-2025 Alyssa Ross <hi@alyssa.is>

backtick -E dir { mktemp -d /run/vm/by-id/XXXXXX }
backtick -E id { basename -- $dir }
if { useradd -P /run -Urd / -s /bin/nologin gpu-${id} }

if {
  elgetpositionals

  if { mkdir -p /run/configs/${id}/fs }

  if {
    ln -s /usr/lib/spectrum/img/appvm/blk /usr/lib/spectrum/img/appvm/vmlinux
      /run/configs/${id}
  }

  if { ln -s /run/configs/${id} ${dir}/config }

  if { create-vm-dependencies $id }

  if {
    nsenter --mount=${dir}/mount
    cd ${dir}/fs/config
    if { redirfd -w 1 type echo flatpak }
    mount-flatpak $@
  }

  piperw 4 3
  background {
    fdclose 3
    fdmove 0 4

    # Wait for the VMM to be up, then start the VM.
    if { redirfd -w 1 /dev/null head -1 }
    vm-start $id
  }
  fdclose 4

  foreground { run-vmm $id }
}

if { s6-instance-delete -- /run/service/vm-services $id }

if { umount ${dir}/mount } # mount namespace
if { umount ${dir}/mount } # private bind mount

# Atomically swap the VM directory with an empty one, which will be ignored by
# lsvm, then remove it, so we never have half a VM directory.
if { mkdir /run/vm/by-id/.${id} }
if { exch /run/vm/by-id/.${id} $dir }
background { rm -rf /run/vm/by-id/.${id} $dir }