1980s/1990s 68k C cross (and not so cross) compilers

Mark Green markwgreen at rogers.com
Sat Nov 21 10:09:46 CST 2015


When I was doing 68K development work in the 1990s we used the GNU C compiler to cross compile.  It was a popular choice, so you might want to give it a try.

-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Philip Pemberton
Sent: November 21, 2015 5:54 AM
To: cctalk <cctalk at classiccmp.org>
Subject: 1980s/1990s 68k C cross (and not so cross) compilers

Hi there,

I'm working on reverse engineering a radio navigation receiver (surprisingly not GPS, something else... Datatrak if anyone's heard of
it) for the purpose of either repurposing the hardware or building up some kind of demo rig.

A lot of my effort at the moment seems to be identifying C Library functions and naming them. Ideally, I'd like to identify the compiler and CLib and feed that into the disassembler to eliminate that work.

Does anyone know which 68000 compilers were available in 1993, and which could produce ROM code? Or a few?



I've looked at Aztec C68K but ruled it out on the basis that the _strlen library function doesn't match up -- this is the one from the ROM:

_strlen:
  movea.l  4(sp), a0
  move.l   a0, d0
_strlen_l001:
  tst.b    (a0+)
  bne.s    _strlen_l001
  sub.l    a0, d0
  not.l    d0
  rts


Aztec is identical up to the bne, then:

  sub.l    d0, a0
  move.l   a0, d0
  sub,l    #1, d0
  rts

Which is one instruction longer... so it's not Aztec.


Other parts of the system apparently used VME-bus modules... so this wasn't a small operation.

Anyway, whatever compiler this is, it pulls in Motorola's Fast Floating Point library.


Thanks,
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/


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