void Host::initialize() {
initCPU();
initGPU();
initOS();
}
// **********************************************************************
// **********************************************************************
// OS startup
//
// 1. Init OS
// 2. Define reset longjmp vector
// 3. Define global system semaphores
// 4. Create CLI task
// 5. Enter scheduling/idle loop
//
int main(int argc, char* argv[])
{
// save context for restart (a system reset would return here...)
int resetCode = setjmp(reset_context);
superMode = TRUE; // supervisor mode
switch (resetCode)
{
case POWER_DOWN_QUIT: // quit
powerDown(0);
printf("\nGoodbye!!");
return 0;
case POWER_DOWN_RESTART: // restart
powerDown(resetCode);
printf("\nRestarting system...\n");
case POWER_UP: // startup
break;
default:
printf("\nShutting down due to error %d", resetCode);
powerDown(resetCode);
return resetCode;
}
// output header message
printf("%s", STARTUP_MSG);
// initalize OS
if ( resetCode = initOS()) return resetCode;
// create global/system semaphores here
//?? vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
charReady = createSemaphore("charReady", BINARY, 0);
inBufferReady = createSemaphore("inBufferReady", BINARY, 0);
keyboard = createSemaphore("keyboard", BINARY, 1);
tics1sec = createSemaphore("tics1sec", BINARY, 0);
tics10thsec = createSemaphore("tics10thsec", BINARY, 0);
tics10secs = createSemaphore("tics10secs", COUNTING, 0);
//?? ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
// schedule CLI task
createTask("myShell", // task name
P1_shellTask, // task
MED_PRIORITY, // task priority
argc, // task arg count
argv); // task argument pointers
// HERE WE GO................
// Scheduling loop
// 1. Check for asynchronous events (character inputs, timers, etc.)
// 2. Choose a ready task to schedule
// 3. Dispatch task
// 4. Loop (forever!)
while(1) // scheduling loop
{
// check for character / timer interrupts
pollInterrupts();
// schedule highest priority ready task
if ((curTask = scheduler()) < 0) continue;
// dispatch curTask, quit OS if negative return
if (dispatcher() < 0) break;
} // end of scheduling loop
// exit os
longjmp(reset_context, POWER_DOWN_QUIT);
return 0;
} // end main
// **********************************************************************
// **********************************************************************
// OS startup
//
// 1. Init OS
// 2. Define reset longjmp vector
// 3. Define global system semaphores
// 4. Create CLI task
// 5. Enter scheduling/idle loop
//
int main(int argc, char* argv[])
{
// All the 'powerDown' invocations must occur in the 'main'
// context in order to facilitate 'killTask'. 'killTask' must
// free any stack memory associated with current known tasks. As
// such, the stack context must be one not associated with a task.
// The proper method is to longjmp to the 'reset_context' that
// restores the stack for 'main' and then invoke the 'powerDown'
// sequence.
// save context for restart (a system reset would return here...)
int resetCode = setjmp(reset_context);
superMode = TRUE; // supervisor mode
switch (resetCode)
{
case POWER_DOWN_QUIT: // quit
powerDown(0);
printf("\nGoodbye!!");
return 0;
case POWER_DOWN_RESTART: // restart
powerDown(resetCode);
printf("\nRestarting system...\n");
break;
case POWER_UP: // startup
break;
default:
printf("\nShutting down due to error %d", resetCode);
powerDown(resetCode);
return 0;
}
// output header message
printf("%s", STARTUP_MSG);
// initalize OS
initOS();
// create global/system semaphores here
//?? vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
charReady = createSemaphore("charReady", BINARY, 0);
inBufferReady = createSemaphore("inBufferReady", BINARY, 0);
keyboard = createSemaphore("keyboard", BINARY, 1);
tics1sec = createSemaphore("tics1sec", COUNTING, 0);
tics10thsec = createSemaphore("tics10thsec", COUNTING, 0);
tics10sec = createSemaphore("tics10sec", COUNTING, 0);
dcChange = createSemaphore("dcChange", BINARY, 0);
//?? ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
// schedule CLI task
createTask("myShell", // task name
P1_shellTask, // task
MED_PRIORITY , // task priority
argc, // task arg count
argv); // task argument pointers
// HERE WE GO................
// Scheduling loop
// 1. Check for asynchronous events (character inputs, timers, etc.)
// 2. Choose a ready task to schedule
// 3. Dispatch task
// 4. Loop (forever!)
while(1) // scheduling loop
{
// check for character / timer interrupts
pollInterrupts();
// schedule highest priority ready task
if ((curTask = scheduler()) < 0) continue;
// dispatch curTask, quit OS if negative return
if (dispatcher() < 0) break;
} // end of scheduling loop
// exit os
longjmp(reset_context, POWER_DOWN_QUIT);
return 0;
} // end main
