Unresolved Inclusion, priv

Altera_Forum · ‎05-09-2011

Good day forum People

I am a total noob to nios2. I am trying to run a uart IRQ but because of an unresolved inclusion: My main c files code is:

# include "system.h"# include "altera_avalon_uart_regs.h"# include "sys/alt_irq.h"# include <stdio.h># include "altera_avalon_pio_regs.h"# include <alt_types.h>
# define RX_BUFFER_SIZE 1024
unsigned char rx_buffer;
void IsrUart()
{
    IOWR_ALTERA_AVALON_UART_TXDATA(UART_BASE,0x03);
    int sr;
    IOWR_ALTERA_AVALON_PIO_DATA(OUT_8PIO_BASE,0x2);
    sr = IORD_ALTERA_AVALON_UART_STATUS(UART_BASE);
    if(sr & ALTERA_AVALON_UART_STATUS_RRDY_MSK)
    {
        rx_buffer=IORD_ALTERA_AVALON_UART_RXDATA(UART_BASE);
    }
    IOWR_ALTERA_AVALON_UART_RXDATA(UART_BASE,rx_buffer);
    if (rx_buffer==0x55)
        IOWR_ALTERA_AVALON_PIO_DATA(OUT_8PIO_BASE,rx_buffer);
}
void InitUart()
{
    IOWR_ALTERA_AVALON_UART_TXDATA(UART_BASE,0x02);
int context_uart;
alt_irq_register(UART_IRQ,&context_uart,IsrUart);
alt_irq_enable (UART_IRQ);
}
int main(void)
{
    IOWR_ALTERA_AVALON_UART_TXDATA(UART_BASE,0x01);
    InitUart();
    IOWR_ALTERA_AVALON_PIO_DATA(OUT_8PIO_BASE,0x00);
while(1)
{
    usleep(1000000);
    IOWR_ALTERA_AVALON_UART_TXDATA(UART_BASE,0x11);
}
return 0;
}

Every time I try to build it I get the error:

undefined reference to `alt_irq_enable'

I've traced it all the way through alt_irq.h and found that the function is declared in alt_legacy_irq.h which is included in alt_irq. If I manually go and get this file and included it the error goes away but my interrupt never gets executed. Any help would be much appreciated.

Altera_Forum · ‎05-18-2011

Hello,

You did not configure the control register of the UART to specify which interrupt you want to activate (cf Embedded Peripherals IP User Guide pp 7-11 to 7-15). So it is normal that the ISR is never executed.

Regarding the function alt_irq_enable, you don't need it, by default the interrupts are active. You need this function only if you want to deativate an interrupt and reactivate it later.

Jérôme