uart.cpp

#include "asm.h"
#include "general.h"
#include "intr.h"
#include "rtlib.h"
#include "term.h"
#include "thread.h"
#include "uart.h"

#ifdef USE_IRQ4_FOR_UART

void irq3() {
  ASSERT_INTERRUPTS_DISABLED();
  ACKNOWLEDGE_IRQ(3);
  // Interrupt 4 handles COM 2 and COM 4
  debug_write("\033[41m irq3 UART \033[0m");

  uint8 com2_iir = inb(COM2_PORT_BASE + UART_8250_IIR);
  uint8 com4_iir = inb(COM4_PORT_BASE + UART_8250_IIR);

  bool caught_something = FALSE;

  if (UART_IIR_PENDING(com2_iir)) {
    caught_something = TRUE;
    uint8 params[2] = {2, com2_iir};
    send_gambit_int(GAMBIT_UART_INT, params, 2);
  }

  if (UART_IIR_PENDING(com4_iir)) {
    caught_something = TRUE;
    uint8 params[2] = {4, com4_iir};
    send_gambit_int(GAMBIT_UART_INT, params, 2);
  }

  if (!(caught_something)) {
    debug_write("Warning: ghost interrupt of IRQ3");
  }
}

/* void show_debug(uint8 iir) { */
/*     uint8 cause = UART_IIR_GET_CAUSE(iir); */
/*     switch (cause) { */
/*         case UART_IIR_MODEM: */
/*             debug_write("UART_IIR_MODEM"); */
/*             break; */
/*         case UART_IIR_TRANSMITTER_HOLDING_REG: */
/*             debug_write("UART_IIR_TRANSMITTER_HOLDING_REG"); */
/*             break; */
/*         case UART_IIR_RCV_LINE: */
/*             debug_write("UART_IIR_RCV_LINE"); */
/*             break; */
/*         case UART_IIR_DATA_AVAIL: */
/*             debug_write("UART_IIR_DATA_AVAIL"); */
/*             break; */
/*         case UART_IIR_TIMEOUT: */
/*             debug_write("UART_IIR_TIMEOUT"); */
/*             break; */
/*         default: */
/*             debug_write("Illegal UART interrupt cause"); */
/*             break; */
/*     } */
/* } */

void irq4() {
  ASSERT_INTERRUPTS_DISABLED();
  ACKNOWLEDGE_IRQ(4);

  uint8 com1_iir = inb(COM1_PORT_BASE + UART_8250_IIR);
  uint8 com3_iir = inb(COM3_PORT_BASE + UART_8250_IIR);

  bool caught_something = FALSE;

  if (UART_IIR_PENDING(com1_iir)) {
    caught_something = TRUE;
    uint8 params[2] = {1, com1_iir};
    send_gambit_int(GAMBIT_UART_INT, params, 2);
  }

  if (UART_IIR_PENDING(com3_iir)) {
    caught_something = TRUE;

    uint8 params[2] = {3, com3_iir};
    send_gambit_int(GAMBIT_UART_INT, params, 2);
  }

  if (!(caught_something)) {
    debug_write("Warning: ghost interrupt of IRQ4");
  }
}
#endif