Using UART FD

Hello,

This is my first use of Software drivers. I'm working with the Quartus standard version 16.0.

when I used the "altera_avalon_uart_write" and "altera_avalon_uart_read" functions, things go right.. but when trying to use FD (altera_avalon_uart_write_fd and altera_avalon_uart_read_fd) , the parameter SP points to a false base address although the file has been correctly opened, it returns a valid value (!=NULL).

my code is :

int main()

{

altera_avalon_uart_state* sp_UART_0;

altera_avalon_uart_state* sp_UART_1;

sp_UART_0->base = UART_0_BASE;

sp_UART_1->base = UART_1_BASE;

char tx_buffer[8] = "BITBANG";

char rx_buffer[8];

alt_fd* fp_uart_1;

alt_fd* fp_uart_0;

fp_uart_1= open ("/dev/uart_1", O_RDWR); //Open file for reading and writing

fp_uart_0= open ("/dev/uart_0",O_RDWR); //Open file for reading and writing

printf("call init uart\n");

altera_avalon_uart_init(sp_UART_1, UART_1_IRQ_INTERRUPT_CONTROLLER_ID,UART_1_IRQ);

altera_avalon_uart_init(sp_UART_0, UART_0_IRQ_INTERRUPT_CONTROLLER_ID,UART_0_IRQ);

int wr = altera_avalon_uart_write_fd (fp_uart_1,tx_buffer,sizeof(tx_buffer)) ;

printf("wr = %d\n",wr);

alt_busy_sleep(1000000); / delay 1us /// 1 s

int rd = altera_avalon_uart_read_fd (fp_uart_0,rx_buffer,sizeof(tx_buffer)) ;

alt_busy_sleep(1000000); / delay 1us /// 1 s

printf(" rd = %d\n",rd);

printf("rx_buffer = '%s'\n\n",rx_buffer);

printf("sp_UART_0 base = 0x%08X \n", sp_UART_0->base);

printf("sp_UART_0 ctrl = 0x%08X \n", sp_UART_0->ctrl);

printf("sp_UART_0 tx_buf = '%s' \n", sp_UART_0->tx_buf);

printf("sp_UART_0 rx_buf = '%s' \n\n\n", sp_UART_0->rx_buf);

printf("sp_UART_1 base = 0x%08X \n", sp_UART_1->base);

printf("sp_UART_1 ctrl = 0x%08X \n", sp_UART_1->ctrl);

printf("sp_UART_1 tx_buf = '%s' \n", sp_UART_1->tx_buf);

printf("sp_UART_1 rx_buf = '%s' \n\n", sp_UART_1->rx_buf);

printf(" rx_buffer = %s\n",rx_buffer);

altera_avalon_uart_close (fp_uart_1) ;

altera_avalon_uart_close (fp_uart_0) ;

free(fp_uart_1);

free(fp_uart_0);

return 0;

}

I'm not sure if I'm missing or using things wrong, any help would be much appreciated. Thank you in advance