Re: [Q] PowerPC compilation questions.

Mohd Hanafiah Abdullah <napi@cs.indiana.edu> writes:
>[what's the Power PC stack frame format like?]


>p.s. Is there an ABI for the PowerPC out there? Would appreciate any
> pointers.


Actually your "p.s." open up a huge can of worms !!


Yes, there is an ABI for PowerPC, as a matter of fact there are at least 4
ABI's that I know of.


First, there is the AIX ABI. This is written by IBM (obviously, since
they own AIX) and is largely a carryover from the RS/6000 (POWER) AIX ABI.
It is currently getting a new coat of "whitewash" (I mean that explicitly
!) and be call the PowerOpen ABI.


Second, there is the SVR4 ABI, written by SunSoft, Yes, you read that
right, Sun is porting Solaris to the PowerPC architecture. Even stranger,
the SVR4 ABI (which has been out in draft form for several months) is the
IBM Workplace OS. The Workplace OS (or whatever IBM is calling it this
week) is based on the Mach kernel (what isn't these days) and will "host"
Solaris, OS/2 (!), OS/Open (a RTOS from IBM), and DOS/Windows emulators
(although they may actually run on top of OS/2).


WNT is actively being ported to PowerPC and I'm pretty certain that they
will have their own unique ABI !


Finally, of course, Apple has a unique ABI fro their Power MAC's with
System 7.


All of these ABI, have enough differences to make them incompatible, and
force compiler writers to have different compilers, assembler and linkers
for each OS. Even the object files format are different (AIX uses XCOFF,
SVR4 uses ELF and WNT and S7 are both unique).


Finally, to answer one of your questions specifically, neither the
AIX/PowerOpen ABI nor the SVR4/Workplace ABI uses a FRAME POINTER (!) and
both use R1 as the STACK POINTER which grows toward high memory.
Jack
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