Help Porting i386_get_ioperm

azrail1222 · 12-04-2004, 09:11 PM

I have a few lines of code that is in dammit (http://www.csh.rit.edu/projects/dammit/) and I am not a BSD person at all. So I am looking for anyone to help port the following lines of code to linux.

Code:

   #define BPL (sizeof(u_long) * 8)
   int port = 0x378;
   u_long iom[32];

   if(i386_get_ioperm(iom) == -1) {
        perror("get_ioperm");
        return 1;
    }
    iom[port / BPL] ^= (1 << (port % BPL));
    if(i386_set_ioperm(iom) == -1) {
        perror("set_ioperm");
        return 1;
    }

leonidg · 12-05-2004, 01:36 AM

look at the following example:
----------------------------------------------------------------------------------------------------------
/*
* example.c: very simple example of port I/O
*
* This code does nothing useful, just a port write, a pause,
* and a port read. Compile with `gcc -O2 -o example example.c',
* and run as root with `./example'.
*/

#include <stdio.h>
#include <unistd.h>
#include <sys/io.h>
#include <stdlib.h>

#define BASEPORT 0x378 /* lp1 */

int main()
{
/* Get access to the ports */
if (ioperm(BASEPORT, 2, 1)) {perror("ioperm"); exit(1);}

/* Set the data signals (D0-7) of the port to all low (0) */
outb(100, BASEPORT);

/* Sleep for a while (100 ms) */
usleep(100000);

/* Read from the status port (BASE+1) and display the result */
printf("status: %d\n", inb(BASEPORT ));

/* We don't need the ports anymore */
if (ioperm(BASEPORT, 3, 0)) {perror("ioperm"); exit(1);}

exit(0);
}

/* end of example.c */

leonidg · 12-05-2004, 01:39 AM

By the way I am looking for a similar thing to ioperm, but for port that ioperm does not support.
If You know how can I write directly to an adress that I know in C or assembler, please contact with me.
Thanks

azrail1222 · 12-05-2004, 02:04 AM

Thanks leonidg, but I am not sure if that is what I am looking for because I don't see where you are able to read the current state of the port. Then edit, and resore it with the code you provided.

leonidg · 12-05-2004, 02:11 AM

function inb(PORT) returns the current state of the port and outb(...,port) edits it