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Re: more evil firmwares found

Matthew Palmer wrote:
On Sun, Apr 18, 2004 at 09:12:31PM -0400, Evan Prodromou wrote:

"DA" == Don Armstrong <don@donarmstrong.com> writes:

   DA> Yes, and we've pretty much rejected it. While they might
   DA> actually use ASM, I've yet to run into someone who regularly
   DA> codes (and modifies their code) in machine language.

That may be because you don't write firmware for embedded systems.

Do you?  And if so, do you regularly hand-hack opcodes?  I've never done it,
and my degree is in Computer Engineering, with a fair emphasis on embedded
systems development.  I've coded for a tiny development board in 80C196KC
assembly language and C, and I've seen embedded code written in Java (Ugh!)
and BASIC (Ugh**2), but I have never seen anyone attempt to do any serious
development with nothing but a hex editor.  Yes, we all knew the general
idea, but it was never posited as a serious development method.

I've done it a few times in the past when I only had a 16-bit assembler (way back!) but I needed to do some 32-bit register work on a 386 (tasm:) It actually worked, except when I put in the wrong number somewhere and then then my directory disappeared!

But for other things, you can write things like for the programmable DAC converters (or ADC for that matter). It is actually *easier* to write stuff like that in hex than attempting to write/modify another assembler. Of course, first you have to write a program for something like the Cypress EZ-USB FX chip so that it loads the program onto the DAC or ADC - ie. firmware loads more firmware. But that can be done in assembly or even C.

Some chips only have a handful of op codes (like 4 or whatever). The entire programs can be only a few to a few dozen of bytes.

- Adam

Building your applications one byte at a time

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