Ubuntu 26.04 LTS guest end-to-end:
- cidata-driven autoinstall pipeline (subiquity user-data + nested
cloud-init bootcmd) in disk_util.c. Static NAT IP, ssh-via-vsock
marker, serial-debug kernel cmdline injected into ESP grub.cfg by
iso-patch.exe. Five separate firstboot pipeline fixes get the VM
to GDM unattended on Hyper-V Gen 2.
- Linux guest stack under tools/linux/:
- appsandbox-agent (vsock :1 control + clipboard helper spawn)
- appsandbox-audio (snd-aloop -> vsock :4)
- appsandbox-display (KMS framebuffer capture -> vsock :2)
- appsandbox-input (uinput injection <- vsock :3)
- appsandbox-clipboard (XCB selection bridge <-> vsock :5/:6)
Helper binaries staged via release/resources/linux/.
- asb_drm DRM module: virtual single-CRTC display sink the host
captures over vsock. Platform-bus, DRIVER_GEM/MODESET/ATOMIC/RENDER,
linear shmem framebuffers. asb-evict-simpledrm.service unbinds the
EFI simple-framebuffer before display-manager so mutter binds
asb_drm as the sole DRM card.
- dxgkrnl vendored byte-identical from microsoft/WSL2-Linux-Kernel
linux-msft-wsl-6.18.y with our DKMS/out-of-tree shim (dxgkrnl_compat.h
+ Kbuild + dkms.conf). Autoinstall late-commands dkms-builds against
every /target/lib/modules/<kver> so kernel-version drift between ISO
and post-update reboot still leaves a working .ko.
- wsl-mesa custom build (Mesa 25.3 + d3d12 gallium + microsoft-
experimental dzn Vulkan). Installs to /opt/wsl-mesa parallel to
Ubuntu's stock Mesa. Prebuilt tarball for ubuntu-26.04-amd64
shipped under tools/linux/wsl-mesa/prebuilt/ (21 MB).
- Per-VM GPU acceleration policy:
- /etc/systemd/user-environment-generators/50-appsandbox-gpu
emits GALLIUM_DRIVER=d3d12 + LD_LIBRARY_PATH + VK_DRIVER_FILES
into the user@1000 systemd-user environment when /dev/dxg and
/opt/wsl-mesa are present. Inherited by every app-*.scope a
.desktop launch creates.
- /etc/systemd/user/org.gnome.Shell@.service.d/no-gpu.conf
UnsetEnvironment= strips these for the compositor — mutter
stays on llvmpipe so asb_drm scanout works (the d3d12 pipe has
no GBM compatibility with asb_drm).
- /usr/local/bin/appsandbox-gpu wrapper for terminal-launched
opt-in GPU acceleration (probes /dev/dxg; no-op on no-GPU VMs).
- Host changes:
- vm_display_idd.c, vm_clipboard.c, vm_agent.c, vm_ssh_proxy.c,
asb_display.c: hcs_service_guid(os_type, port) so the same code
paths reach the per-OS service identifiers (HV_GUID for Windows,
vsock template for Linux).
- asb_core.c: linux_create_thread builds an empty VHDX, cidata
ISO with extras (agent ELFs, dxgkrnl src, asb_drm src, wsl-mesa
tarball, wsl-deps libs), and boots the desktop ISO + cidata.
- hcs_vm.c: HostLxssLib Plan9 share appended for Linux VMs;
VideoMonitor + ComPorts retained for serial debug.
- gpu_enum.c/h: gpu_append_lxsslib_share helper.
- vm_clipboard.c file-drop support (CF_HDROP / x-special/gnome-
copied-files round-trip).
- vm_display_idd.c: 32-bit S32_LE PCM audio path matches the
Linux daemon's snd-aloop capture format.
- iso-patch.c gains a patch_ubuntu_esp_grub_for_debug pass that
rewrites /EFI/ubuntu/grub.cfg via the FAT32 ESP, plus a qcow2->
vhdx converter with a RFC 1951 DEFLATE inflater for compressed
cluster handling.
- wsl-deps: Microsoft's libd3d12.so / libd3d12core.so / libdxcore.so
fetched on demand from the public NuGet feed
pkgs.dev.azure.com/shine-oss/wsl (no auth). Staged at
/opt/appsandbox/wsl-deps on the guest and put on /etc/ld.so.conf.d
rather than /usr/lib/wsl/lib (which is overlaid by the agent's
9P mount).
UI: web/{app.js,index.html} expose Linux VM creation + GPU selection,
distribution dropdown for cached Ubuntu ISOs, and the ISO picker for
custom images.
set nat as default network, set IP address automatically when in NAT mode, don't open the rdp display on win11 home, fix a bug where display would open again at shutdown if it was closed
James Stringer