int io_init() {
iobuf_init( &otrain );
iobuf_init( &oterm );
bwsetspeed( COM1, 2400 );
if ( bwsetfifo( COM1, OFF ) || bwsetfifo( COM2, OFF ) ){
return -1;
}
TERM_FLAG = (int *)( UART2_BASE + UART_FLAG_OFFSET );
TERM_DATA = (int *)( UART2_BASE + UART_DATA_OFFSET );
TRAIN_FLAG = (int *)( UART1_BASE + UART_FLAG_OFFSET );
TRAIN_DATA = (int *)( UART1_BASE + UART_DATA_OFFSET );
return 0;
}
void initialize_kernel() {
bwsetfifo(COM2, OFF);
void (**syscall_handler)() = (void (**)())0x28;
*syscall_handler = &kernel_enter;
void (**irq_handler)() = (void (**)())0x38;
*irq_handler = &irq_enter;
initialize_cache();
initialize_memory();
initialize_fine_timer();
initialize_scheduling();
initialize_tasks();
initialize_messaging();
initialize_events();
initialize_waiting();
}
int main( int argc, char* argv[] ) {
// setup COM2/terminal
bwsetfifo( COM2, OFF );
// setup peripherals and handlers
kernel_init();
// Create idle task
struct task* idle_task = task_create(&idle_task_entry, PRIORITY_IDLE, -1);
scheduler_add(idle_task);
// bootstrap first user task
struct task* first_task = task_create(&first_task_entry, PRIORITY_HIGHEST, -1);
scheduler_add(first_task);
long idleTicks = 0;
long userTicks = 0;
struct task *current_task;
int request;
long elapsed;
while (1) {
current_task = scheduler_get_next();
if (current_task == 0) {
break;
}
ACTIVATE:
// Time the execution of the task
elapsed = rtc_get_ticks();
// run the user task
request = task_activate(current_task);
elapsed = rtc_get_ticks() - elapsed;
if (current_task == idle_task) {
idleTicks += elapsed;
}
userTicks += elapsed;
switch (__interrupt_type) {
case INT_TYPE_HWI:
// handle the interrupt request and determine if we should preempt the running task
if (interrupts_handle_irq(current_task) == HWI_CONTINUE && current_task != idle_task) {
goto ACTIVATE;
} else {
scheduler_add(current_task);
}
break;
case INT_TYPE_SWI:
// handle the system call request and determine if we should shutdown
if (sys_handle_request(current_task, request) == -1) {
goto shutdown;
}
break;
default:
KASSERT(0, "We got a weird interrupt type... %d", __interrupt_type);
break;
}
}
shutdown:
kernel_shutdown();
// reset the scrolling window, in case it exists!
bwprintf(COM2, CURSOR_SCROLL, 0, 999);
bwprintf(COM2, CURSOR_CLEAR_SCREEN);
// int i;
// for (i = 0; i < MAX_NUM_TASKS; i++) {
// task_print(COM2, i);
// }
printSensorTicks();
bwprintf(COM2, "Idle time: %d%%\r\n", ((idleTicks * 100) / userTicks));
bwprintf(COM2, "Kernel exiting.\r\n");
return 0;
}