From b52f37602968768901d2dd83ccf966d953a532f0 Mon Sep 17 00:00:00 2001 From: user Date: Fri, 17 Jul 2026 13:43:10 +0200 Subject: kernel: sys_sleep - a cooperative delay off the DIV timer (+ ping pacing) There was no time source at all (IRQ vectors just reti; scheduler is purely cooperative). The DIV register (FF04) free-runs at 16384 Hz regardless of interrupts, so sys_sleep accumulates DIV deltas across SchedYields (other procs keep running) until the requested number of 1/64-second units elapse. - SYS_SLEEP(34): B = 1/64s units; libc gsleep(units) / msleep(ms) wrappers. - ping now msleep(800) between echoes, so it paces like real ping instead of blasting all four at once. Verified real-time (capped emulator): replies land ~0.85s apart. In --uncapped runs the delay is GB-time (fast wall-clock), as expected. --- c/libc.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'c/libc.c') diff --git a/c/libc.c b/c/libc.c index 9da63bc..a48a64c 100644 --- a/c/libc.c +++ b/c/libc.c @@ -1,6 +1,15 @@ /* gbos libc C helpers (compiled once, linked into every program). */ #include "gbos.h" +/* sleep for approximately 'ms' milliseconds (cooperative; other procs run). + The kernel counts in 1/64-second units (~15.6 ms), so we round ms to that. */ +void msleep(unsigned int ms) { + unsigned int u = ms >> 4; /* ~ms/15.6, close enough for a delay */ + if (u > 255) u = 255; + if (u == 0 && ms) u = 1; + gsleep((unsigned char)u); +} + /* print an unsigned int in decimal */ void putu(unsigned int n) { char buf[5]; -- cgit v1.3.1-sl0p