From: Andrew Apted <ajapted@netspace.net.au>
  To  : ggi-develop@eskimo.com
  Date: Sun, 5 Jul 1998 23:52:29 +1000

Re: kgicon difficulties |-< (and new tarballs |->)

Jonas Borgström writes:

>  I have tested the code. After some small changes the Millennium driver
>  compiled and inserted correctly. But when I type con2fbmap 0 1 the computer
>  locks stone solid, can't even telnet in. 

Ouch.

>  Where is the source for con2fbmap?

Below :-).

>  Does anybody know what the problem is?
  
One possibility: it has got the wrong framebuffer address, and starts
trashing kernel memory when the consoles try to draw themselves (after
the con2fbmap).

Could you send the output of dmesg after inserting the module ?  

Cheers,
_____________________________________________  ____
                                               \  /
  Andrew Apted   <andrew@ggi-project.org>       \/
  

=============================================================================

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <linux/fb.h>


const char *fbpath = "/dev/fb0current";		/* any frame buffer will do */

const char *programname;

void Usage(void)
{
    fprintf(stderr, "\nUsage: %s console [framebuffer]\n\n", programname);
    exit(1);
}

int main(int argc, char *argv[])
{
    int do_write = 0;
    int fd;
    struct fb_con2fbmap map;

    programname = argv[0];
    switch (argc) {
	case 3:
	    do_write = 1;
	    map.framebuffer = atoi(argv[2]);
	case 2:
	    map.console = atoi(argv[1]);
	    break;
	default:
	    Usage();
    }
    if ((fd = open(fbpath, O_RDONLY)) == -1) {
	fprintf(stderr, "open %s: %s\n", fbpath, strerror(errno));
	exit(1);
    }
    if (do_write) {
	if (ioctl(fd, FBIOPUT_CON2FBMAP, &map)) {
	    fprintf(stderr, "ioctl FBIOPUT_CON2FBMAP: %s\n", strerror(errno));
	    exit(1);
	}
    } else {
	if (ioctl(fd, FBIOGET_CON2FBMAP, &map)) {
	    fprintf(stderr, "ioctl FBIOGET_CON2FBMAP: %s\n", strerror(errno));
	    exit(1);
	}
	printf("console %d is mapped to framebuffer %d\n", map.console,
	       map.framebuffer);
    }
    close(fd);
    exit(0);
}