Subject: Re: disk ioctl's and checksums
To: None <henson@colossus.mathcs.rhodes.edu>
From: Niklas Hallqvist <niklas@appli.se>
List: amiga-dev
Date: 06/28/1995 15:28:50
>>>>> "henson" == henson  <henson@colossus.mathcs.rhodes.edu> writes:

henson>  Second, should the checksum of a disklabel always be 0? Some
henson> of the functions in fd.c make the assumption that it should,
henson> but from looking at the code, I think they should check the
henson> calculated checksum against the checksum stored in the
henson> disklabel itself.

If you say what I think you are, it's the same thing, provided the
checksum is an XOR one.  By checksumming a block via XOR and this
block contains a previously calculated checksum for the block
excluding the checksum itself, you will get zero as a result.  Straigth
boolean algebra, try it...

However, I haven't checked the source, so I'm not sure this is the
case here.

NH