[MiNT] Mxalloc() and memory protection

[Philipp Donzé <philipp.donze@epfl.ch>]

Hi,

While solving a problem with memory protection, I "googled" the 
internet for documentation on Mxalloc().

In the past (and in a test application which I run under MiNT 1.16.1) I 
always used Mxalloc(size, 0x20 | 2) to allocate global memory 
(preferably) in ST-RAM. This works for me :-)

The question is: is this the proper way to allocate global memory which 
is shared between TOS applications?

When you look at the various documentations which can be found on the 
internet (Atari Compendium, TOS.HYP), you'll read that the "bit 3" has 
a special meaning which indicates that the "protection flags" should be 
evaluated or not.

And my experiences tell me that this is not true. Or at least this bit 
is not needed.

Is there a maintained documentation of Mxalloc() as MiNT implements it? 
(I've read the mint2.pap file in the mint programmer documentation 
confirms my ideas but dates from 1999.)


The internet sources which give bit 3 a special meaning are:
  Atari Compendium 
(http://www.fortunecity.com/skyscraper/apple/308/html/gemdos.htm)
  TOS.HYP (http://www.mbernstein.de/atari/prog/tos/050d05.htm)


regards

Philipp