1 files changed, 9 insertions, 0 deletions
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];