/*      $OpenBSD: seves_mmio.c,v 1.2 2025/11/27 11:55:08 hshoexer Exp $ */

/*
 * Copyright (c) 2025 Hans-Joerg Hoexer <hshoexer@yerbouti.franken.de>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/mman.h>
#include <sys/param.h>

#include <err.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define PCI_MMIO_BAR_BASE       0xF0000000ULL

static void
handler(int sig, siginfo_t *sip, void *ctx)
{
        printf("signo %d, code %d, errno %d\n", sip->si_signo, sip->si_code,
            sip->si_errno);
        if (sig != SIGBUS)
                errx(1, "expected SIGBUS: %d", sig);
        if (sip->si_code != BUS_ADRERR)
                errx(1, "expected BUS_ADRERR: %d", sip->si_code);

        exit(0);
}

int
main(int argc, char **argv)
{
        struct sigaction        sa;
        int                      fd;
        char                    *p;
        volatile char            v;

        memset(&sa, 0, sizeof(sa));
        sa.sa_sigaction = handler;
        sa.sa_flags = SA_SIGINFO;
        if (sigaction(SIGBUS, &sa, NULL) == -1)
                err(2, "sigaction");

        fd = open("/dev/xf86", O_RDWR);
        if (fd == -1)
                err(2, "open");

        p = mmap(NULL, sizeof(v), PROT_READ, 0, fd, PCI_MMIO_BAR_BASE);
        if (p == MAP_FAILED)
                err(2, "mmap");

        v = *p;

        errx(1, "expected signal");
}