void context_switch(){
pcb * transition;
pcb * temp;
atomic_up();
transition = running;
transition->frame_ptr = old_fp;
if(transition->next_process != NULL){
ready_queue[prio] = ready_queue[prio]->next_process;
temp = ready_queue[prio];
while(temp->next_process != NULL){
temp = temp->next_process;
}
temp->next_process = transition;
transition->next_process = NULL;
}
transition->process_state = READY_STATE;
clear_priority();
while(1){
if(ready_queue[prio] != NULL){
if(ready_queue[prio]->process_state == READY_STATE){
running = ready_queue[prio];
running->process_state = RUNNING_STATE;
old_fp = running->frame_ptr;
atomic_down();
return;
} else if(ready_queue[prio]->process_state == NEW_STATE){
running = ready_queue[prio];
running->process_state = RUNNING_STATE;
atomic_down();
temp_sp = running->stack_ptr;
asm("move.l temp_sp, %d0");
asm("move.l %d0, %a7");
process_bootstrap(running);
return;
}
break;
} else {
prio = (prio + 1) % 4;
}
}
return;
}
/*
* Initialize all interrupts associated with UART
*/
void uart_init() {
#ifdef _IO_DEBUG
rtx_dbug_outs((CHAR *) "Enter: uart_init\r\n");
#endif
UINT32 mask;
// Disable all interupts
atomic_up();
// Store the serial ISR at user vector #64
asm( "move.l #asm_serial_entry,%d0" );
asm( "move.l %d0,0x10000100" );
SERIAL1_UCR = 0x10; // Reset the entire UART
SERIAL1_UCR = 0x20; // Reset the receiver
SERIAL1_UCR = 0x30; // Reset the transmitter
SERIAL1_UCR = 0x40; // Reset the error condition
SERIAL1_ICR = 0x17; // Install the interupt
SERIAL1_IVR = 64; // Install the interupt
SERIAL1_IMR = 0x02; // enable interrupts on rx only
SERIAL1_UBG1 = 0x00;// Set the baud rate
#ifdef _CFSERVER_ // add -D_CFSERVER_ for cf-server build
SERIAL1_UBG2 = 0x49; // cf-server baud rate 19200
#else
SERIAL1_UBG2 = 0x92; // lab board baud rate 9600
#endif
SERIAL1_UCSR = 0xDD;// Set clock mode
SERIAL1_UMR = 0x13; // Setup the UART (no parity, 8 bits )
SERIAL1_UMR = 0x07; // Setup the rest of the UART (noecho, 1 stop bit)
SERIAL1_UCR = 0x05; // Setup for transmit and receive
// Enable interupts
mask = SIM_IMR;
mask &= 0x0003ddff;
SIM_IMR = mask;
// Enable all interupts
atomic_down();
char_in = '!';
char_out = '\0';
}
VOID c_serial_handler( VOID )
{
atomic_up();
CharIn = '\0';
BYTE interrupt_status;
interrupt_status = SERIAL1_USR;
SERIAL1_IMR = 3;
if( interrupt_status & 1 )
{
CharIn = SERIAL1_RD;
CharOut = CharIn;
}
while (!(interrupt_status & 4))
{
interrupt_status = SERIAL1_USR;
}
SERIAL1_IMR = 2;
if ( interrupt_status & 4 )
{
switch(CharIn){
case '\r':
uprintf(crlfgt);
if(command_flag == 1){
store_message((CHAR)'\0');
void * p = request_memory_block();
send_message(KCD_PID,write_message(p, kcd_msg));
command_flag = 0;
clear_message();
}
break;
case '%':
SERIAL1_WD = '%';
command_flag = 1;
break;
case '!':
SERIAL1_WD = CharOut;
display_queue_all();
sleep(6);
break;
case '@':
SERIAL1_WD = CharOut;
task_manager();
sleep(6);
break;
case '#':
display_mailbox();
sleep(6);
break;
default:
if(command_flag == 1){
store_message((CHAR)CharOut);
}
SERIAL1_WD = CharOut;
break;
}
}
atomic_down();
return;
}
/*
* This function is called by the assembly STUB function
*/
void uart_handler() {
// Disable all interupts
atomic_up();
#ifdef _IO_DEBUG
rtx_dbug_outs((CHAR *) "Enter: uart_handler\r\n");
rtx_dbug_outs((CHAR *) "Reading data...\r\n");
#endif
// irene said this should be enough - would be
// very rare if it wasn't ready to read
while (!(SERIAL1_UCSR & 1)) { }
char_in = SERIAL1_RD;
#ifdef _IO_DEBUG
rtx_dbug_outs((CHAR *) "Determining what to do with char...\r\n");
#endif
struct io_message * msg;
switch(char_in) {
#ifdef _HOTKEYS_DEBUG
case '!':
rtx_dbug_outs((CHAR *) "'!' hotkey detected...\r\n");
print_queues(); // print processes on ready queue and priorities
break;
case '@':
rtx_dbug_outs((CHAR *) "'@' hotkey detected...\r\n");
print_mem_blocked(); // print processes on memory blocked queue and priorities
break;
case '#':
rtx_dbug_outs((CHAR *) "'#' hotkey detected...\r\n");
print_msg_blocked(); // print processes on message blocked queue and priorities
break;
case '$':
rtx_dbug_outs((CHAR *) "'$' hotkey detected...\r\n");
print_availible_mem_queue(); // print available memory queue
break;
case '^':
rtx_dbug_outs((CHAR *) "'^' hotkey detected...\r\n");
print_used_mem_queue(); // print used memory queue
break;
case '&':
rtx_dbug_outs((CHAR *) "'&' hotkey detected...\r\n");
output_kcd_buffer(); // print kcd buffer
break;
case '*':
rtx_dbug_outs((CHAR *) "'*' hotkey detected...\r\n");
print_cmds(); // print valid commands
break;
#endif
default:
#ifdef _IO_DEBUG
rtx_dbug_outs((CHAR *) "Sending message to KCD proc...\r\n");
#endif
if (!are_blocks_available()) {
atomic_down();
return;
}
msg = (io_message *)request_memory_block();
// reset tx/rx and send it to kcd
msg->tx = UART_PID;
msg->rx = KCD_PID;
msg->msg[0] = char_in;
send_message(KCD_PID, msg);
break;
}
// Enable all interupts
atomic_down();
}