#! /bin/sh

#rom extension extractor (ported to shell from the pascal version of 1997)
#see http://www.firmware.com/support/bios/romext.htm for more info
#extracts system, scsi, video bios
#gurkan@linuks.mine.nu, www.linuks.mine.nu

#scan from c0000 - f0000 in 512 byte blocks
#UŠ{l}{code}
#l*512=length of the code including headers

#200 hex = 512, dd wants 512 blocks
case "$@" in
    -nbc|--i-dont-have-no-bc)
	start=1536
        last=1920
    ;;
    *)
	start=`echo "ibase=16;C0000/200"|bc`
        last=`echo "ibase=16;F0000/200"|bc`
    ;;
esac

for a in `seq $start 1 $last`; do
    b=`dd if=/dev/mem skip=$a count=1 2>/dev/null |head -c2`

    case "$@" in
        -nbc|--i-dont-have-no-bc)
	    location=$[a*512]
        ;;
        *)
	    location=`echo "obase=16; $a*512"|bc`
	;;
    esac

    echo -ne "Please wait, scanning... $location"

    if [ "$b" = "UŠ" ]; then
	size=`dd if=/dev/mem skip=$a count=1 2>/dev/null |tail -c+3`
	s=`echo $size |perl -e 'print ord(<>);'`
	
	case "$@" in
	    -nbc|--i-dont-have-no-bc)
		file=$[a*512]
		size=$[s*512]
            ;;
	    *)
	        file=`echo "obase=16; $a*512"|bc`
		size=`echo $s*512 |bc`
	    ;;
	esac
	
	echo -e "\nFound something at $file ($size)"
	dd if=/dev/mem of=${file}.rom skip=$a count=$s 2>/dev/null
	strings ${file}.rom |awk '{if (length($0)>40)print $0}' |grep "[A-Z]"
    fi
done

#save bios rom
case "$@" in
    -nbc|--i-dont-have-no-bc)
	start=1920
	count=128
    ;;
    *)
	start=`echo "ibase=16;F0000/200"|bc`
        count=`echo 1*65536/512|bc`
    ;;
esac
echo -e "\nFound system bios at F0000 (65536)"
dd if=/dev/mem of=F0000.rom skip=$start count=$count 2>/dev/null