#include "context.h"

void scheduler()
{
   //
   // set the variable current_task to point to the descriptor of the task
   // that should be scheduled next. Example: current_task = taskdesc+1 would
   // schedule the cyclic scheduler because taskdesc+1 was the pointer used 
   // when the cyclic scheduler task was created. current_task = taskdesc+0
   // would schedule the background (aperiodic) thread.
   //
}

void cyclic_scheduler(void)
{
   //
   // put your cyclic scheduler code here. After the job(s) assigned to a time slice
   // is/are complete, call yield(). This will relinquish the processor until the next
   // time the cyclic scheduler is scheduled.
   //
}

void create_task(task_descriptor xdata *td, void (code *task)(void), char idata *stack)
{
   td->t_pc = task;
   td->t_sp = stack - 1;
   td->psw = 0;
}

char idata stack1[16]; // stack space for the cyclic scheduler

main()
{
   WDTCN = 0xde;  // disable watchdog
   WDTCN = 0xad;
   XBR2 = 0x40;   // enable port output
   XBR0 = 4;      // enable uart 0
   OSCXCN = 0x67; // turn on external crystal
   TMOD = 0x20;   // wait 1ms using T1 mode 2
   TH1 = -167;    // 2MHz clock, 167 counts - 1ms
   TR1 = 1;
   while ( TF1 == 0 ) { }          // wait 1ms
   while ( !(OSCXCN & 0x80) ) { }  // wait till oscillator stable
   OSCICN = 8;    // switch over to 22.1184MHz
   SCON0 = 0x50;  // 8-bit, variable baud, receive enable
   TH1 = -6;      // 9600 baud
   P1MDOUT = 0x40;

   context_init();

   create_task(taskdesc+1,cyclic_scheduler,stack1);

   EA = 1; // enable interrupts and start multi-tasking
   for ( ; ; )
   {
      // put your code to execute aperiodic tasks here
   }