UART interrupt

I'm in the process of converting an old NIOS II project over to eCos. The interrupts do not work when I use the eCos API. Here is the relevant code.

#include <cyg/hal/system.h># include <cyg/kernel/kapi.h>
unsigned char abycin;
volatile unsigned int byrxptr = 0;
unsigned int bywrptr = 0;
cyg_uint32 uart_debug_isr(cyg_vector_t vector, cyg_addrword_t data)
{
    volatile int clr_int;
  
  // Block this interrupt from occurring until this ISR completes.
  cyg_interrupt_mask(vector);
  // Tell the processor that we have received the interrupt.
  cyg_interrupt_acknowledge(vector);
  if (!(IORD_ALTERA_AVALON_UART_STATUS(UART_DEBUG_BASE) & 0x02))    
 {
    abycin = IORD_ALTERA_AVALON_UART_RXDATA(UART_DEBUG_BASE);
    if(byrxptr < (RXBUF_SIZE_DEBUG - 2)) byrxptr++;
    else byrxptr = 0;
  }
  else clr_int = IORD_ALTERA_AVALON_UART_RXDATA(UART_DEBUG_BASE); // read UDR if framing error just to clear interrupt
  // Allow this interrupt to occur again.
  //cyg_interrupt_unmask (vector);
  // Tell the kernel that chained interrupt processing is done. 
  //return CYG_ISR_HANDLED;
  return CYG_ISR_HANDLED | CYG_ISR_CALL_DSR;
}
void uart_debug_dsr(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data)
{
  //printf("DSR\n");
  //out_str("DSR\n");
  cyg_interrupt_unmask(vector);
}
void out_str(char *s)
{
  unsigned char *c;
  
  for(c = s;; c++)
  {
  if(*c == 0)
    break;
  out_char((unsigned char)*c);
  } 
}
void out_char(unsigned char c)
{
  while(!(IORD_ALTERA_AVALON_UART_STATUS(UART_DEBUG_BASE) & 0x40));
  IOWR_ALTERA_AVALON_UART_TXDATA(UART_DEBUG_BASE, c);
}
void cyg_user_start(void)
{
  int divisor = 0;
  int old = 0;
  cyg_handle_t uart_debug_handle, timer_handle;
  cyg_interrupt uart_debug_intr, timer_intr;
  cyg_interrupt_create(UART_DEBUG_IRQ, 99, 0, &uart_debug_isr, &uart_debug_dsr, &uart_debug_handle, &uart_debug_intr);
  cyg_interrupt_attach(uart_debug_handle);
  cyg_interrupt_disable();
  /* Other initialization tasks performed here */
  cyg_interrupt_enable();
  cyg_interrupt_unmask(UART_DEBUG_IRQ);
  while(1)
  {
     while (bywrptr != byrxptr) // Check to see if any data has been received by the Uart
     {
        printf("bywrptr != byrxptr\n");
        ProcessRxBuf(); // Process new data received from Uart
      }
      //while (rtdwrptr != rtdrxptr)
        //MDP();
  }
}