Xprot was not open source. Here's a reverse engineered version from much later https://notabug.org/freemangordon/pulseaudio-nokia/src/fremantle/src/xprot/temper

Xprot was not open source. Here's a reverse engineered version from much later https://notabug.org/freemangordon/pulseaudio-nokia/src/fremantle/src/xprot/temperature.c https://notabug.org/freemangordon/pulseaudio-nokia/src/frema... which turns out to read the ambient/battery temperature rather than coil-specific one. Kind of a similar idea, but more of a really simple precursor to what Asahi did, with no kernel level protection.