Unl0kr is an [osk-sdl] clone written in [LVGL] and rendering directly to the Linux framebuffer. As a result, it doesn't depend on GPU hardware acceleration.
For some background on how unl0kr came to be, see postmarketOS/osk-sdl#121.
While we continue to tweak and extend Unl0kr, it is deemed fully functional. Unl0kr has been set up as the default disk unlocker on [postmarketOS][package-pmos] and was also packaged for other distrubtions including [Arch Linux][package-arch] and [Debian][package-debian].
When pulling changes from the remote later, either use `git pull --recurse-submodules` or manually run `git submodule update` as needed after pulling.
Once you have the sources, you can build the app and run it in a VT. Unless your user account has special privileges, `sudo` will be needed to access input device files.
```
$ meson _build
$ meson compile -C _build
$ sudo chvt 2
$ sudo ./_build/unl0kr
```
With meson <0\.55use`ninja`insteadof`meson compile`\.
## Valgrind
> Using C without Valgrind is like skydiving without a parachute.
To be able to use Valgrind, add `default_options: ['optimization=g']` in the `project` section of `meson.build` and rebuild. Afterwards you can run the application with Valgrind's leaks check enabled via
```
sudo valgrind --leak-check=yes ./_build/unl0kr
```
## Backends
Unl0kr supports multiple LVGL display drivers, referred to as "backends".
- fbdev
- drm (optional)
The active backend can be selected via the `general.backend` option in the configuration file.
Note that if [libdrm] is installed, the DRM backend will be compiled in automatically. It's possible to prevent this behaviour by passing the `with-drm` option to meson.
```
$ meson _build -Dwith-drm=disabled
```
## Fonts
In order to work with [LVGL], fonts need to be converted to bitmaps, stored as C arrays. Unl0kr currently uses a combination of the [OpenSans] font for text and the [FontAwesome] font for pictograms. For both fonts only limited character ranges are included to reduce the binary size. To (re)generate the C file containing the combined font, run the following command
```
$ ./regenerate-fonts.sh
```
Below is a short explanation of the different unicode ranges used above.
- [OpenSans]
- Basic Latin (`0x0020-0x007F`)
- Latin-1 supplement (`0x00A0-0x00FF`)
- Latin extended A (`0x0100-0x017F`)
- Greek and Coptic (`0x0370-0x03FF`)
- General punctuation (`0x2000-0x206F`)
- Currency symbols (`0x20A0-0x20CF`)
- Mathematical operators (`0x2200-0x22FF`)
- [FontAwesome]
- Standard `LV_SYMBOL_*` glyphs (`0xF001,0xF008,0xF00B,0xF00C,0xF00D,0xF011,0xF013,0xF015,0xF019,0xF01C,0xF021,0xF026,0xF027,0xF028,0xF03E,0xF0E0,0xF304,0xF043,0xF048,0xF04B,0xF04C,0xF04D,0xF051,0xF052,0xF053,0xF054,0xF067,0xF068,0xF06E,0xF070,0xF071,0xF074,0xF077,0xF078,0xF079,0xF07B,0xF093,0xF095,0xF0C4,0xF0C5,0xF0C7,0xF0C9,0xF0E7,0xF0EA,0xF0F3,0xF11C,0xF124,0xF158,0xF1EB,0xF240,0xF241,0xF242,0xF243,0xF244,0xF287,0xF293,0xF2ED,0xF55A,0xF7C2,0xF8A2`)
Unl0kr uses [squeekboard layouts] converted to C via [squeek2lvgl]. To regenerate the layouts, ensure that you have pipenv installed (e.g. via `pip install --user pipenv`) and then run
```
$ ./regenerate-layouts.sh
```
from the root of the repository.
## Generating screenshots
To generate screenshots in a variety of common sizes, build unl0kr and then run
```
$ sudo ./regenerate-screenshots _build/unl0kr
```
where `_build/unl0kr` is the location of the unl0kr binary. Note that you may have to adapt some of the settings inside the script depending on the device you're using to generate the screenshots.
## Screen recording
For demonstration purposes you can record the framebuffer device, e.g. with ffmpeg:
The [lv_port_linux_frame_buffer] project served as a starting point for the codebase.
# License
Unl0kr is licensed under the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
The [OpenSans] font is licensed under the Apache License 2.0.
The [FontAwesome] font is licensed under the Open Font License version 1.1.
