Timed waiting with hal_wait()

kernel/hal/hal.h

@@ -19,6 +19,7 @@ size_t hal_strspn(const char *s, const char *accept);
 char *hal_strcpy(char *dest, const char *src);
 char *hal_strchr(const char *s, int c);
 void hal_init_withmalloc(void);
+void hal_wait(uint32_t ms);
 
 #if defined(__x86_64__)
 # define HAL_PAGE_SIZE 0x1000

kernel/hal/x86_64/hal.c

@@ -34,3 +34,7 @@ void hal_init_withmalloc(void) {
   hal_intr_disable();
 }
 
+void hal_wait(uint32_t ms) {
+  pit_wait(ms);
+}
+