#!/usr/bin/perl -w
use Getopt::Std;
use constant MINROMSIZE => 8192;
use constant MAXROMSIZE => 262144;
use constant PCI_PTR_LOC => 0x18; # from beginning of ROM
use constant PCI_HDR_SIZE => 0x18;
use constant PNP_PTR_LOC => 0x1a; # from beginning of ROM
use constant PNP_HDR_SIZE => 0x20;
use constant PNP_CHKSUM_OFF => 0x9; # bytes from beginning of PnP header
use constant PNP_DEVICE_OFF => 0x10; # bytes from beginning of PnP header
use constant PCI_VEND_ID_OFF => 0x4; # bytes from beginning of PCI header
use constant PCI_DEV_ID_OFF => 0x6; # bytes from beginning of PCI header
use constant PCI_SIZE_OFF => 0x10; # bytes from beginning of PCI header
use constant UNDI_PTR_LOC => 0x16; # from beginning of ROM
use constant UNDI_HDR_SIZE => 0x16;
use constant UNDI_CHKSUM_OFF => 0x05;
use strict;
use vars qw(%opts);
use bytes;
sub getromsize ($) {
my ($romref) = @_;
my $i;
print STDERR "BIOS extension ROM Image did not start with 0x55 0xAA\n"
if (substr($$romref, 0, 2) ne "\x55\xaa");
my $size = ord(substr($$romref, 2, 1)) * 512;
for ($i = MINROMSIZE; $i < MAXROMSIZE and $i < $size; $i *= 2) { }
print STDERR "$size is a strange size for a boot ROM\n"
if ($size > 0 and $i > $size);
return ($size);
}
sub addident ($) {
my ($romref) = @_;
return (0) unless (my $s = $opts{'i'});
# include the terminating NUL byte too
$s .= "\x00";
my $len = length($s);
# Put the identifier in only if the space is blank
my $pos = length($$romref) - $len - 2;
return (0) if (substr($$romref, $pos, $len) ne ("\xFF" x $len));
substr($$romref, $pos, $len) = $s;
return ($pos);
}
sub pcipnpheaders ($$) {
my ($romref, $identoffset) = @_;
my ($pci_hdr_offset, $pnp_hdr_offset);
$pci_hdr_offset = unpack('v', substr($$romref, PCI_PTR_LOC, 2));
$pnp_hdr_offset = unpack('v', substr($$romref, PNP_PTR_LOC, 2));
# Sanity checks
if ($pci_hdr_offset < PCI_PTR_LOC + 2
or $pci_hdr_offset > length($$romref) - PCI_HDR_SIZE
or $pnp_hdr_offset < PNP_PTR_LOC + 2
or $pnp_hdr_offset > length($$romref) - PNP_HDR_SIZE
or substr($$romref, $pci_hdr_offset, 4) ne 'PCIR'
or substr($$romref, $pnp_hdr_offset, 4) ne '$PnP') {
$pci_hdr_offset = $pnp_hdr_offset = 0;
} else {
printf "PCI header at %#x and PnP header at %#x\n",
$pci_hdr_offset, $pnp_hdr_offset;
}
if ($pci_hdr_offset > 0) {
my ($pci_vendor_id, $pci_device_id);
# if no -p option, just report what's there
if (!defined($opts{'p'})) {
$pci_vendor_id = unpack('v', substr($$romref, $pci_hdr_offset+PCI_VEND_ID_OFF, 2));
$pci_device_id = unpack('v', substr($$romref, $pci_hdr_offset+PCI_DEV_ID_OFF, 2));
printf "PCI Vendor ID %#x Device ID %#x\n",
$pci_vendor_id, $pci_device_id;
} else {
substr($$romref, $pci_hdr_offset + PCI_SIZE_OFF, 2)
= pack('v', length($$romref) / 512);
($pci_vendor_id, $pci_device_id) = split(/,/, $opts{'p'});
substr($$romref, $pci_hdr_offset+PCI_VEND_ID_OFF, 2)
= pack('v', oct($pci_vendor_id)) if ($pci_vendor_id);
substr($$romref, $pci_hdr_offset+PCI_DEV_ID_OFF, 2)
= pack('v', oct($pci_device_id)) if ($pci_device_id);
}
}
if ($pnp_hdr_offset > 0 and defined($identoffset)) {
# Point to device id string at end of ROM image
substr($$romref, $pnp_hdr_offset+PNP_DEVICE_OFF, 2)
= pack('v', $identoffset);
substr($$romref, $pnp_hdr_offset+PNP_CHKSUM_OFF, 1) = "\x00";
my $sum = unpack('%8C*', substr($$romref, $pnp_hdr_offset,
PNP_HDR_SIZE));
substr($$romref, $pnp_hdr_offset+PNP_CHKSUM_OFF, 1) = chr(256 - $sum);
}
}
sub undiheaders ($) {
my ($romref) = @_;
my ($undi_hdr_offset);
$undi_hdr_offset = unpack('v', substr($$romref, UNDI_PTR_LOC, 2));
# Sanity checks
if ($undi_hdr_offset < UNDI_PTR_LOC + 2
or $undi_hdr_offset > length($$romref) - UNDI_HDR_SIZE
or substr($$romref, $undi_hdr_offset, 4) ne 'UNDI') {
$undi_hdr_offset = 0;
} else {
printf "UNDI header at %#x\n", $undi_hdr_offset;
}
if ($undi_hdr_offset > 0) {
substr($$romref, $undi_hdr_offset+UNDI_CHKSUM_OFF, 1) = "\x00";
my $sum = unpack('%8C*', substr($$romref, $undi_hdr_offset,
UNDI_HDR_SIZE));
substr($$romref, $undi_hdr_offset+UNDI_CHKSUM_OFF, 1) = chr(256 - $sum);
}
}
sub writerom ($$) {
my ($filename, $romref) = @_;
open(R, ">$filename") or die "$filename: $!\n";
print R $$romref;
close(R);
}
sub checksum ($) {
my ($romref) = @_;
substr($$romref, 6, 1) = "\x00";
my $sum = unpack('%8C*', $$romref);
substr($$romref, 6, 1) = chr(256 - $sum);
# Double check
$sum = unpack('%8C*', $$romref);
if ($sum != 0) {
print "Checksum fails\n"
} elsif ($opts{'v'}) {
print "Checksum ok\n";
}
}
sub makerom () {
my ($rom, $romsize);
getopts('3xi:p:s:v', \%opts);
$ARGV[0] or die "Usage: $0 [-s romsize] [-i ident] [-p vendorid,deviceid] [-x] [-3] rom-file\n";
open(R, $ARGV[0]) or die "$ARGV[0]: $!\n";
# Read in the whole ROM in one gulp
my $filesize = read(R, $rom, MAXROMSIZE+1);
close(R);
defined($filesize) and $filesize >= 3 or die "Cannot get first 3 bytes of file\n";
print "$filesize bytes read\n" if $opts{'v'};
# If PXE image, just fill the length field and write it out
if ($opts{'x'}) {
substr($rom, 2, 1) = chr((length($rom) + 511) / 512);
&writerom($ARGV[0], \$rom);
return;
}
# Size specified with -s overrides value in 3rd byte in image
# -s 0 means round up to next 512 byte block
if (defined($opts{'s'})) {
if (($romsize = oct($opts{'s'})) <= 0) {
# NB: This roundup trick only works on powers of 2
$romsize = ($filesize + 511) & ~511
}
} else {
$romsize = &getromsize(\$rom);
# 0 put there by *loader.S means makerom should pick the size
if ($romsize == 0) {
# Shrink romsize down to the smallest power of two that will do
for ($romsize = MAXROMSIZE;
$romsize > MINROMSIZE and $romsize >= 2*$filesize;
$romsize /= 2) { }
}
}
if ($filesize > $romsize) {
print STDERR "ROM size of $romsize not big enough for data, ";
# NB: This roundup trick only works on powers of 2
$romsize = ($filesize + 511) & ~511;
print "will use $romsize instead\n"
}
# Pad with 0xFF to $romsize
$rom .= "\xFF" x ($romsize - length($rom));
if ($romsize >= 128 * 1024) {
print "Warning: ROM size exceeds extension BIOS limit\n";
}
substr($rom, 2, 1) = chr(($romsize / 512) % 256);
print "ROM size is $romsize\n" if $opts{'v'};
my $identoffset = &addident(\$rom);
&pcipnpheaders(\$rom, $identoffset);
&undiheaders(\$rom);
# 3c503 requires last two bytes to be 0x80
substr($rom, MINROMSIZE-2, 2) = "\x80\x80"
if ($opts{'3'} and $romsize == MINROMSIZE);
&checksum(\$rom);
&writerom($ARGV[0], \$rom);
}
sub modrom () {
my ($rom);
getopts('p:v', \%opts);
$ARGV[0] or die "Usage: $0 [-p vendorid,deviceid] rom-file\n";
open(R, $ARGV[0]) or die "$ARGV[0]: $!\n";
# Read in the whole ROM in one gulp
my $filesize = read(R, $rom, MAXROMSIZE+1);
close(R);
defined($filesize) and $filesize >= 3 or die "Cannot get first 3 bytes of file\n";
print "$filesize bytes read\n" if $opts{'v'};
&pcipnpheaders(\$rom);
&undiheaders(\$rom);
&checksum(\$rom);
&writerom($ARGV[0], \$rom);
}
# Main routine. See how we were called and behave accordingly
if ($0 =~ m:modrom(\.pl)?$:) {
&modrom();
} else {
&makerom();
}
exit(0);
