arch/x86/serial_port.cpp

   1 #include "arch_asm.h"
   2 #include "serial_port.h"
   3 #include "interrupts.h"
   4
   5 using namespace arch;
   6 namespace arch {
   7 delegate<void, const char> serialport_handler;
   8 }
   9 extern "C"  void serialport_irq(void);
  10 void arch::serialport_init(delegate<void, const char> sp_hndl) {
  11
  12         serialport_handler = sp_hndl;
  13
  14         /* Get access to the clock registers */
  15         outb(0x3fb,inb(0x3fb)|(1<<7));
  16
  17         /* Set transmission speed (the highest possible) */
  18         outb(0x3f8, 1);
  19         outb(0x3f9, 0);
  20
  21         /* Restore default registers access */
  22         outb(0x3fb,inb(0x3fb)& ~(1<<7));
  23
  24         /* Set 8bit data format */
  25         outb(0x3fb, 3);
  26
  27         /* Call interrupt at every received byte */
  28         outb(0x3f9, 1);
  29
  30         /* Set IRQ4 */
  31         set_irq(0x24, serialport_irq);
  32 }
  33
  34 void arch::serialport_send(const char sign) {
  35         outb(0x3f8, sign);
  36 }
  37
  38 extern "C" void arch::serialport_received() {
  39         unlock_irqs(4);
  40         serialport_handler(inb(0x3f8));
  41 }
  42
  43 __asm__ __volatile__("serialport_irq:\n\tcall serialport_received\n\tiret");