tg-clock

A tiny no_std clock helper crate for bare-metal RISC-V S-mode experiments.

It provides a minimal timer setup flow used in rCore tutorial style kernels:

• enable S-mode timer interrupts
• read current time CSR
• schedule next timer event via SBI

Installation

[dependencies]
tg-clock = "0.1.0"

Minimal Example

#![no_std]

use tg_clock::{clock_set_next_event, get_time, init};

pub fn kernel_init() {
    init();
}

pub fn on_timer_interrupt() {
    let _now = get_time();
    clock_set_next_event();
}

API Summary

• init()
  • enables sstatus.SIE and sie.STIE
  • schedules the first timer event
• clock_set_next_event()
  • programs next timer interrupt through SBI set_timer
• get_time() -> usize
  • reads current value from RISC-V time CSR

Notes

• Target: riscv64gc-unknown-none-elf
• Runtime: bare-metal / no_std
• Requires SBI implementation compatible with tg-rcore-tutorial-sbi