+++ /dev/null
-#include "types.h"
-#include "defs.h"
-#include "traps.h"
-#include "x86.h"
-
-// Register definitions for the Intel
-// 8253/8254/82C54 Programmable Interval Timer (PIT).
-
-#define IO_TIMER1 0x040 // 8253 Timer #1
-#define IO_TIMER2 0x048 // 8253 Timer #2 (EISA only)
-
-// Frequency of all three count-down timers; (TIMER_FREQ/freq) is the
-// appropriate count to generate a frequency of freq hz.
-
-#define TIMER_FREQ 1193182
-#define TIMER_DIV(x) ((TIMER_FREQ+(x)/2)/(x))
-
-#define TIMER_CNTR0 (IO_TIMER1 + 0) // timer 0 counter port
-#define TIMER_CNTR1 (IO_TIMER1 + 1) // timer 1 counter port
-#define TIMER_CNTR2 (IO_TIMER1 + 2) // timer 2 counter port
-#define TIMER_MODE (IO_TIMER1 + 3) // timer mode port
-#define TIMER_SEL0 0x00 // select counter 0
-#define TIMER_SEL1 0x40 // select counter 1
-#define TIMER_SEL2 0x80 // select counter 2
-#define TIMER_INTTC 0x00 // mode 0, intr on terminal cnt
-#define TIMER_ONESHOT 0x02 // mode 1, one shot
-#define TIMER_RATEGEN 0x04 // mode 2, rate generator
-#define TIMER_SQWAVE 0x06 // mode 3, square wave
-#define TIMER_SWSTROBE 0x08 // mode 4, s/w triggered strobe
-#define TIMER_HWSTROBE 0x0a // mode 5, h/w triggered strobe
-#define TIMER_LATCH 0x00 // latch counter for reading
-#define TIMER_LSB 0x10 // r/w counter LSB
-#define TIMER_MSB 0x20 // r/w counter MSB
-#define TIMER_16BIT 0x30 // r/w counter 16 bits, LSB first
-#define TIMER_BCD 0x01 // count in BCD
-
-void
-pit8253_timerinit(void)
-{
- // initialize 8253 clock to interrupt 100 times/sec
- outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
- outb(IO_TIMER1, TIMER_DIV(100) % 256);
- outb(IO_TIMER1, TIMER_DIV(100) / 256);
- irq_enable(IRQ_TIMER);
-}
ide_init(); // disk
bootothers(); // boot other CPUs
if(!ismp)
- pit8253_timerinit(); // uniprocessor timer
+ timer_init(); // uniprocessor timer
userinit(); // first user process
// enable interrupts on this processor.
scheduler();
}
-void
+static void
bootothers(void)
{
extern uchar _binary_bootother_start[], _binary_bootother_size[];
--- /dev/null
+// Intel 8253/8254/82C54 Programmable Interval Timer (PIT).
+// Only used on uniprocessors;
+// SMP machines use the local APIC timer.
+
+#include "types.h"
+#include "defs.h"
+#include "traps.h"
+#include "x86.h"
+
+#define IO_TIMER1 0x040 // 8253 Timer #1
+
+// Frequency of all three count-down timers;
+// (TIMER_FREQ/freq) is the appropriate count
+// to generate a frequency of freq Hz.
+
+#define TIMER_FREQ 1193182
+#define TIMER_DIV(x) ((TIMER_FREQ+(x)/2)/(x))
+
+#define TIMER_MODE (IO_TIMER1 + 3) // timer mode port
+#define TIMER_SEL0 0x00 // select counter 0
+#define TIMER_RATEGEN 0x04 // mode 2, rate generator
+#define TIMER_16BIT 0x30 // r/w counter 16 bits, LSB first
+
+void
+timer_init(void)
+{
+ // Interrupt 100 times/sec.
+ outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
+ outb(IO_TIMER1, TIMER_DIV(100) % 256);
+ outb(IO_TIMER1, TIMER_DIV(100) / 256);
+ irq_enable(IRQ_TIMER);
+}