# Xorg

The desktop is X11, on the framebuffer. This replaces [wayland.md](wayland.md)
as the plan for Gate 3 of [1.0.md](1.0.md); Wayland stays on file and is not
being worked on.

## Why X and not Wayland

Every Wayland compositor worth running -- labwc, and everything else built on
wlroots -- needs DRM/KMS, libinput, udev and libseat. DRM/KMS is the largest of
them by far: a kernel graphics subsystem, and in practice a great deal taken
from Linux. Xorg runs on a plain framebuffer through its `fbdev` driver and
reads input through `evdev`, both of which are interfaces SchOS already has.
It is the shorter road to a desktop by a long way, and it brings the window
managers with it: twm first, then Window Maker.

DRM/KMS is not planned. libinput, udev and libseat are worth having for their
own sake and may come later; Xorg does not need them.

## What is built

- **The kernel calls** (`b1323e1`, checked by `cmd/xready`): evdev's queries,
  fbdev's mode-set to the current mode, `KDSETMODE`, `KDSKBMODE`, the
  `VT_PROCESS` switch handshake, and `/sys/bus/pci/devices/*/{boot_vga,
  enable,graphics/fb0}` for libpciaccess.
- **Dynamic linking and `dlopen`** (`4330576`): Xorg loads its drivers as
  modules.
- **`<linux/*.h>`** in the build sysroot, as `ports/linux-headers`.

## What is left, in order

1. **The X client libraries.** xorgproto, xtrans, libXau, libXdmcp,
   xcb-proto, libxcb, libX11, libXext, libXrender, libXfixes, libxkbfile,
   libfontenc, libXfont2, freetype, zlib, pixman, libpciaccess.
2. **Keyboard and fonts.** xkbcomp and xkeyboard-config, the data X compiles
   keymaps from; a misc-fixed font.
3. **The server.** xorg-server built with meson, GLX, glamor and DRI off;
   xf86-video-fbdev; xf86-input-evdev with libevdev and mtdev.
4. **The first picture.** `twm` and `xterm`, started by hand from a VT.
5. **Window Maker**, and an `startx` that works.

The kernel calls were written against what these programs are documented
to do. Each step past it is expected to find a call that was not -- that is
what running the real program is for.