QEMU

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QEMU allows running postmarketOS in virtual machines. The following architectures are available:

Note that running a virtual machine for a foreign architecture (e.g. aarch64 on x86_64) requires CPU emulation which is rather slow. Prefer the native architecture when possible.

Phosh

By default, Phosh has the resolution hard-coded to 720x1440 (like the Librem 5), so the display is cut off on usual 1920x1080 (Full HD) monitors.

You can change the resolution by editing /usr/share/phosh/phoc.ini. By default it contains:

[output:Virtual-1]
# For the x86 VM using QXL to get a phone like geometry
modeline = 87.25  720 776 848 976  1440 1443 1453 1493 -hsync +vsync
mode = 720x1440
scale = 2

To add a new resolution, you need to add a new modeline, then change the mode (and eventually the scale). You can generate the modelines using the cvt tool.

For example, to set the resolution to qHD (540x960):

$ cvt -v 540 960
Warning: Aspect Ratio is not CVT standard.
# 544x960 59.96 Hz (CVT) hsync: 59.72 kHz; pclk: 43.00 MHz
Modeline "544x960_60.00"   43.00  544 576 632 720  960 963 973 996 -hsync +vsync

Note how it changed the horizontal resolution to 544 to match the CVT standard. Weird. Then add the new modeline and change mode:

[output:Virtual-1]
# For the x86 VM using QXL to get a phone like geometry
modeline = 87.25  720 776 848 976  1440 1443 1453 1493 -hsync +vsync
modeline = 43.00  544 576 632 720  960 963 973 996 -hsync +vsync
mode = 544x960
# Maybe it's a bit too large with scale 2 on this resolution? Or maybe not, just test it out :)
scale = 1

Restart QEMU or rc-service lightdm restart, then Phosh should show up with the new resolution. Note that the modeline is necessary to support custom resolutions, you cannot just set the mode.

See also