Host File System not working

AAlas3 · ‎02-17-2020

Hey,

I built a simple Qsys system with Nios inside it and I would like to write and read from file in host machine, so I wrote the following:

#include "stdio.h"

#include "alt_sys_init.c"

int main()

{

FILE* ptr = fopen("Test.txt","w");

fprintf(ptr,"Helloooooo");

fclose(ptr);

return 0;

}

when I run this in debug mode, ptr is NULL, I checked the Host altera_hostfs but still not working

Help Please

Ahmed_H_Intel1 · ‎02-20-2020

Hi,

Please first, make sure you enable the altera_hostfs package by opening the BSP editor>>Software Packages tab>> Check the box in front of the altera_hostfs package.

Next is a sample code to read and write to a file at the host:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
#define BUF_SIZE (50)
 
int main(void)
{
 
FILE= fp_ascii = NULL;
FILE = fp_bin = NULL;
char buffer[BUF_SIZE];
int read_size=1;
 
/* Reading ASCII File from the host*/
fp_ascii = fopen("file path", "r");
    if (fp_ascii == NULL)
        {
           printf("Cannot open the file\n");
           exit(1);
        }
fgets(buffer, sizeof(buffer), fp_ascii);
printf("%s", buffer);
fclose(fp_ascii);
 
 
/* WriteASCII File from the host*/
fp_ascii = fopen("file path", "w");
     if (fp_ascii == NULL)
        {
           printf("Cannot open the file\n");
           exit(1);
        }
strcpy(buffer, "Hellow from NIOS II");
fputs(buffer, fp_ascii);
fclose(fp_ascii);
 
return 0;
 
 
 
}

Regards,

AAlas3 · ‎02-20-2020

It is enabled, anyway I solved the problem: In code when you fopen a file you should write "/mnt/host" with the file path and the pointer will locate the project directory

By the way my name is Ahmad and it is pleasure sir to meet you

Yogesh · ‎07-30-2020

So suppose there is a read.txt file in project directory along side main.c code with path as below :

E:/folder1/project/read.txt

What should path of read.txt shd be in main.c file?
mnt/host/read.txt ???