BFE EngineeringandClaude Fable 5
1d7dec167e
The qemu/ device sim answered the first question off-board: the same kernel family under -M virt gives musl vDSO rate ratio 0.99963 — the generic 6.18 armv7 vDSO is correct, so the board symptom is RV1106 register state (CNTFRQ/CNTVOFF, firmware-owned, secure-world boot chain). - qemu/tests/clockprobe: interval-based musl probe separating RATE error (CNTFRQ) from boot OFFSET (CNTVOFF) — the original single absolute sample cannot distinguish them. - qemu/tests/clock-sanity.sh: VM regression guard asserting the vDSO rate within 1% (PASSES: 1.00026); cross-builds the probe and stages it as payload itself. - kernel/rv1106-enablement/timer/PLAN.md: the DT fix (arm,cpu-registers-not-fw-configured + measured clock-frequency on the board dts) gated on the two bench measurements; c8a3 is currently physically dark, needs hands at the bench. - clockprobe joins the CI test loop. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018HUayid7W5w7jBdb9Rrj1K
26 lines
1.1 KiB
Rust
26 lines
1.1 KiB
Rust
// Differential clock probe for warden-sdk issue #3: compares the musl/vDSO
|
|
// CLOCK_MONOTONIC rate against the kernel's own /proc/uptime over a fixed
|
|
// interval, so boot-time offsets cancel and only the RATE ratio remains.
|
|
use std::{fs, thread, time::Duration};
|
|
|
|
fn mono(clock: libc::clockid_t) -> f64 {
|
|
let mut ts = libc::timespec { tv_sec: 0, tv_nsec: 0 };
|
|
unsafe { libc::clock_gettime(clock, &mut ts) };
|
|
ts.tv_sec as f64 + ts.tv_nsec as f64 / 1e9
|
|
}
|
|
|
|
fn uptime() -> f64 {
|
|
fs::read_to_string("/proc/uptime").unwrap()
|
|
.split_whitespace().next().unwrap().parse().unwrap()
|
|
}
|
|
|
|
fn main() {
|
|
let interval = 10.0;
|
|
let (m0, r0, u0) = (mono(libc::CLOCK_MONOTONIC), mono(libc::CLOCK_MONOTONIC_RAW), uptime());
|
|
thread::sleep(Duration::from_secs_f64(interval));
|
|
let (m1, r1, u1) = (mono(libc::CLOCK_MONOTONIC), mono(libc::CLOCK_MONOTONIC_RAW), uptime());
|
|
let (dm, dr, du) = (m1 - m0, r1 - r0, u1 - u0);
|
|
println!("CLOCKPROBE monotonic={dm:.4} raw={dr:.4} uptime={du:.4} ratio_mono={:.5} ratio_raw={:.5}", dm / du, dr / du);
|
|
println!("CLOCKPROBE abs monotonic={m1:.2} uptime={u1:.2} abs_ratio={:.5}", m1 / u1);
|
|
}
|