Timing is everything

4 files changed, 38 insertions, 81 deletions

diff --git a/kernel/drivers/int.c b/kernel/drivers/int.c
index f6a5134..d5f0a67 100644
--- a/kernel/drivers/int.c
+++ b/kernel/drivers/int.c
@@ -172,19 +172,32 @@ static u32 int_special_handler(struct int_frame *frame)
  * Universal handler
  */
 
+static u8 int_enabled = 1;
+
 u32 int_handler(u32 esp);
 u32 int_handler(u32 esp)
 {
 	struct int_frame *frame = (struct int_frame *)esp;
-	if (frame->int_no < 32)
+	if (frame->int_no < 32) {
 		int_trap_handler(frame);
-	else if (frame->int_no < 48)
+	} else if (int_enabled && frame->int_no < 48) {
 		esp = int_event_handler(frame);
-	else if (frame->int_no >= 128 && frame->int_no < 144)
+	} else if (frame->int_no >= 128 && frame->int_no < 144) {
 		esp = int_special_handler(frame);
-	else
+	} else if (frame->int_no >= 48) {
 		panic("Unknown interrupt: %d\n", frame->int_no);
+	}
 
 	pic_ack(frame->int_no);
 	return esp;
 }
+
+void int_disable(void)
+{
+	int_enabled = 0;
+}
+
+void int_enable(void)
+{
+	int_enabled = 1;
+}
diff --git a/kernel/drivers/pit.c b/kernel/drivers/pit.c
new file mode 100644
index 0000000..abba5e8
--- /dev/null
+++ b/kernel/drivers/pit.c
@@ -0,0 +1,20 @@
+// MIT License, Copyright (c) 2021 Marvin Borner
+
+#include <def.h>
+#include <drivers/cpu.h>
+#include <drivers/pit.h>
+#include <timer.h>
+
+CLEAR static void pit_phase(u32 hz)
+{
+	u32 divisor = 3579545 / 3 / hz;
+	outb(0x43, 0x36); // 01 10 11 0b // CTR, RW, MODE, BCD
+	outb(0x40, (u8)(divisor & 0xFF));
+	outb(0x40, (u8)(divisor >> 8));
+}
+
+CLEAR void pit_install(void)
+{
+	pit_phase(1000);
+	timer_install_handler();
+}
diff --git a/kernel/drivers/rtc.c b/kernel/drivers/rtc.c
index b67829e..0a9a3fd 100644
--- a/kernel/drivers/rtc.c
+++ b/kernel/drivers/rtc.c
@@ -3,10 +3,10 @@
 #include <def.h>
 #include <drivers/cpu.h>
 #include <drivers/rtc.h>
-#include <drivers/timer.h>
 #include <fs.h>
 #include <mem.h>
 #include <str.h>
+#include <timer.h>
 
 static u8 rtc_busy(void)
 {
diff --git a/kernel/drivers/timer.c b/kernel/drivers/timer.c
deleted file mode 100644
index 977647c..0000000
--- a/kernel/drivers/timer.c
+++ /dev/null
@@ -1,76 +0,0 @@
-// MIT License, Copyright (c) 2020 Marvin Borner
-
-#include <def.h>
-#include <dev.h>
-#include <drivers/cpu.h>
-#include <drivers/int.h>
-#include <drivers/rtc.h>
-#include <drivers/timer.h>
-#include <mem.h>
-#include <proc.h>
-
-static u32 timer_ticks = 0;
-
-CLEAR static void timer_phase(int hz)
-{
-	int divisor = 3579545 / 3 / hz;
-	outb(0x43, 0x36); // 01 10 11 0b // CTR, RW, MODE, BCD
-	outb(0x40, (u8)(divisor & 0xFF));
-	outb(0x40, (u8)(divisor >> 8));
-}
-
-u32 timer_get(void)
-{
-	return timer_ticks;
-}
-
-static void timer_handler(void)
-{
-	if (timer_ticks >= U32_MAX)
-		timer_ticks = 0;
-	else
-		timer_ticks++;
-}
-
-// "Delay" function with CPU sleep
-void timer_wait(u32 ticks)
-{
-	u32 eticks = timer_ticks + ticks;
-	while (timer_ticks < eticks)
-		__asm__ volatile("sti\nhlt\ncli");
-}
-
-static struct timer timer_struct(void)
-{
-	struct proc *proc = proc_current();
-	struct timer timer = {
-		.rtc = rtc_stamp(),
-		.ticks.user = proc->ticks.user,
-		.ticks.kernel = proc->ticks.kernel,
-		.time = timer_get(),
-	};
-	return timer;
-}
-
-static res timer_read(void *buf, u32 offset, u32 count)
-{
-	UNUSED(offset);
-
-	struct timer timer = timer_struct();
-	memcpy_user(buf, &timer, MIN(count, sizeof(timer)));
-
-	return MIN(count, sizeof(timer));
-}
-
-// Install timer handler into IRQ0
-CLEAR void timer_install(void)
-{
-	/* hpet_install(10000); // TODO: Find optimal femtosecond period */
-	/* if (!hpet) */
-	timer_phase(1000);
-	int_event_handler_add(0, timer_handler);
-
-	struct dev_dev *dev = zalloc(sizeof(*dev));
-	dev->read = timer_read;
-	dev_add(DEV_TIMER, dev);
-}