[Geekos-devel] timer munging

[Parc <ne...@ri...>]

I've munged together a couple lines to set the timer to 10ms jiffies,
and added a sleep().  Could somebody try these out for me?  For some
reason I don't get the correct timing occasionally.  This patch should
cause the kernel to loop saying "tick" once a second.

Thanks

Index: drivers/timer.c
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
RCS file: /cvsroot/geekos/drivers/timer.c,v
retrieving revision 1.2
diff -c -r1.2 timer.c
*** drivers/timer.c	2001/12/24 15:35:57	1.2
--- drivers/timer.c	2002/01/12 05:10:29
***************
*** 11,16 ****
--- 11,20 ----
  #include "sys/geekos/kthread.h"
  #include "sys/geekos/timer.h"
 =20
+ #define TICKRATE	1193182
+ //#define FIND_RATE(hz) (((TICKRATE + hz) / 2) / hz)
+ #define FIND_RATE(hz) (((TICKRATE + hz) / 2) / hz)
+=20
  // global tick counter
  volatile unsigned long g_numTicks;
 =20
***************
*** 56,61 ****
--- 60,72 ----
 =20
      Print( "Initializing timer...\n" );
 =20
+     //Set the tick rate to 10ms
+     disable_interrupts();
+     out_byte(0x043, 0x34);
+     out_byte(0x040, FIND_RATE(100) & 0xff);
+     out_byte(0x040, FIND_RATE(100) >> 8);
+     enable_interrupts();
+=20
      // Install an interrupt handler for the timer IRQ
      install_irq( TIMER_IRQ, &timer_interrupt_handler );
 =20
***************
*** 63,66 ****
--- 74,83 ----
      irqMask =3D get_irq_mask();
      irqMask &=3D ~(1 << TIMER_IRQ);
      set_irq_mask( irqMask );
+ }
+=20
+ void sleep(int time) {
+    long start =3D g_numTicks + time +1;=20
+    Print("Sleeping from %x to %x\n",g_numTicks,start);
+    while((g_numTicks - start) > 0) ; //spin
  }
Index: include/sys/geekos/timer.h
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
RCS file: /cvsroot/geekos/include/sys/geekos/timer.h,v
retrieving revision 1.2
diff -c -r1.2 timer.h
*** include/sys/geekos/timer.h	2001/12/24 15:35:57	1.2
--- include/sys/geekos/timer.h	2002/01/12 05:10:29
***************
*** 13,17 ****
--- 13,18 ----
  extern volatile unsigned long g_numTicks;
 =20
  void init_timer( void );
+ void sleep( int time );
 =20
  #endif // TIMER_H
Index: kern/main.c
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
RCS file: /cvsroot/geekos/kern/main.c,v
retrieving revision 1.6
diff -c -r1.6 main.c
*** kern/main.c	2001/12/24 15:35:57	1.6
--- kern/main.c	2002/01/12 05:10:30
***************
*** 51,56 ****
--- 53,62 ----
      // Test Join() function
      {
  	struct kernel_thread* child;
+         for(; ;) {
+             sleep(100);
+             Print("tick.\n");
+         }
  	Print( "Starting child...\n" );
  	child =3D start_kernel_thread( &test_join, 0, PRIORITY_NORMAL, FALSE );
  	Join( child );