vystem/docs/shelter/cpu/pit.md

PIT API

In Shelter, the PIT is only used for one purpose: estimating the CPU frequency. It's only used with the PIC, never with the IOAPIC, so the API is volontarily very simple:

• sh_pit_set_frequency(): expect the frequency as argument. Set the PIT to uses this frequency and return nothing

This API is defined inside shelter/lib/include/cpu/pit.h and implemented inside shelter/lib/include/cpu/pic.c.