On Thu, 18 Oct 2001 12:35:23 -0700, Thomas J. Merritt wrote: >|I speculate that their code is obfuscated not because anyone wrote it that >|way deliberately, but because of historical accident, i.e., their legacy. > >Their code is obfuscated in large part because they use cleanly nested >subroutine calls while running in an environment that doesn't have a >memory controller enabled. There are some pretty sick tricks to do >four levels of subroutine calls without touching memory.
I'll support that statement. The BIOS code I have looked at so far does all kinds of things to be able to support return linkage when memory isn't up. Nothing I have seen in the source indicates any deliberate intention to make the code difficult to reverse engineer. Aside from haveing to go through over megabyte of assembly code when I am trying to find a certain area its really not that bad. It could be MUCH worse. >Linuxbios assumes that the hardware works and the you want to run linux >as soon as possible. If you have linuxbios installed and have a hardware Linuxbios also leaves a bunch of stuff to the linux kernel. >I think that PC BIOS code probably doesn't look as bad in source form as >it does in object form, but it stall has to be pretty bad. My experience agrees with this. Course I have only seen 1 vendors code. In the near future though that will expand to 2. >|But so long as they can make a buck on it, it'll be here to stay, until >|that Great Day comes when they can't hire anyone to work on it. And what a buck it is... The ammount in per copy royality alone is huge. Not to mention that it takes $30k to get started. Man I wish I had gotten into BIOS dev long ago. Probally could have made some big money. -- Richard A. Smith Bitworks, Inc. [EMAIL PROTECTED] 501.846.5777 Sr. Design Engineer http://www.bitworks.com
