#include <sys/types.h>
#include <sys/mman.h>
#include <stdio.h>
#include <fcntl.h>
#include <err.h>

struct PIR_header 
{
    int8_t	ph_signature[4];
    u_int16_t	ph_version;
    u_int16_t	ph_length;
    u_int8_t	ph_router_bus;
    u_int8_t	ph_router_dev_fn;
    u_int16_t	ph_pci_irqs;
    u_int16_t	ph_router_vendor;
    u_int16_t	ph_router_device;
    u_int32_t	ph_miniport;
    u_int8_t	ph_res[11];
    u_int8_t	ph_checksum;
} __attribute__ ((packed));

struct PIR_intpin 
{
    u_int8_t	link;
    u_int16_t	irqs;
} __attribute__ ((packed));

struct PIR_entry
{
    u_int8_t		pe_bus;
    u_int8_t		pe_res1:3;
    u_int8_t		pe_device:5;
    struct PIR_intpin	pe_intpin[4];
    u_int8_t	pe_slot;
    u_int8_t	pe_res3;
} __attribute__ ((packed));

struct PIR_table 
{
    struct PIR_header	pt_header;
    struct PIR_entry	pt_entry[0];
} __attribute__ ((packed));

#define SEARCHSIZE 0x20000

static char	*format_ints(u_int16_t mask);

int
main(int argc, char *argv[])
{
    int			fd;
    char		*biosbase, *cp;
    int			offset, i;
    struct PIR_table	*pt;
    struct PIR_header	*ph;
    struct PIR_entry	*pe;
    int			nentry;
    int			ck;

    if ((fd = open("/dev/mem", O_RDONLY)) < 0)
	err(1, "can't open /dev/mem");

    if ((biosbase = mmap(NULL, SEARCHSIZE, PROT_READ, 0, fd, 0xe0000)) == MAP_FAILED)
	err(1, "can't mmap /dev/mem");
    
    pt = NULL;
    for (offset = 0; offset < SEARCHSIZE; offset += 16) {
	if (!strncmp(biosbase + offset, "$PIR", 4)) {
	    pt = (struct PIR_table *)(biosbase + offset);
	    break;
	}
    }
    if (pt == NULL)
	errx(1, "can't find $PIR in BIOS segment");
    ph = &pt->pt_header;
    
    ck = 0;
    for (offset = 0, cp = (char *)pt; offset < ph->ph_length; offset++, cp++)
	ck += *cp;
    ck %= 256;
    if (ck != 0)
	warnx("WARNING: $PIR table checksum mismatch (%d != 0)", ck);

    printf("$PIR table at %p version %x.%x\n", pt, ph->ph_version >> 8, ph->ph_version & 0xff);
    printf("PCI interrupt router at %d:%d.%d vendor 0x%x device 0x%x\n",
	   ph->ph_router_bus, ph->ph_router_dev_fn >> 4, ph->ph_router_dev_fn & 0xf, 
	   ph->ph_router_vendor, ph->ph_router_device);
    printf("PCI-only interrupts %s\n", format_ints(ph->ph_pci_irqs));

    nentry = (ph->ph_length - sizeof(struct PIR_header)) / sizeof(struct PIR_entry);
    
    printf("entry bus slot device\n");
    
    for (offset = 0, pe = &pt->pt_entry[0]; offset < nentry; offset++, pe++) {
	for (i = 0; i < 4; i++) {
	    if (i == 0) {
		printf(" %02d:  %02d   %02d    %02d  INTA", offset, pe->pe_bus, pe->pe_slot, pe->pe_device);
	    } else {
		printf("                     INT%c", 'A' + i);
	    }
	    printf("  %02x  %s\n", pe->pe_intpin[i].link, format_ints(pe->pe_intpin[i].irqs));
	}
	
    }
}

static char *
format_ints(u_int16_t mask)
{
    static char buf[40];
    
    sprintf(buf, "[%s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s]",
	   mask & (1 << 0) ? "0" : " ",
	   mask & (1 << 1) ? "1" : " ",
	   mask & (1 << 2) ? "2" : " ",
	   mask & (1 << 3) ? "3" : " ",
	   mask & (1 << 4) ? "4" : " ",
	   mask & (1 << 5) ? "5" : " ",
	   mask & (1 << 6) ? "6" : " ",
	   mask & (1 << 7) ? "7" : " ",
	   mask & (1 << 8) ? "8" : " ",
	   mask & (1 << 9) ? "9" : " ",
	   mask & (1 << 10) ? "10" : "  ",
	   mask & (1 << 11) ? "11" : "  ",
	   mask & (1 << 12) ? "12" : "  ",
	   mask & (1 << 13) ? "13" : "  ",
	   mask & (1 << 14) ? "14" : "  ",
	   mask & (1 << 15) ? "15" : "  ");
    return(buf);
}