[Coco] lwtools assembler difference

[Bill Pierce]

Dave, you can thank Tormod Volden for the condition of the repo. He came into the picture with the repo in an absolute mess when it was all but abandoned in the midst of the switch from ToolShed to LWTools and SVC to Mercurial and massaged it into one of the best running releases of OS9/NitrOS9 the Coco has ever seen.
And thank William Astle for the work on LWTools. LWTools has made building the repo a breeze...

Now to get it back into NitrOS9 :-)

 

 


Bill Pierce
"Charlie stole the handle, and the train it won't stop going, no way to slow down!" - Ian Anderson - Jethro Tull

 

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-----Original Message-----
From: Dave Philipsen <dave at davebiz.com>
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Sent: Wed, Sep 2, 2015 1:53 pm
Subject: Re: [Coco] lwtools assembler difference


Ok, so I found out that the disk images in the official repository have 
been
assembled correctly with the default operation of the lwasm 
assembler to
generate the 5-bit offset machine code ONLY when forced by 
a literal "0" such
as in ldb 0,x.  For some reason, the disk image that 
I received from a a guy
whose cousin knows a friend of another person 
who generated his own NitrOS9
disk image must have been generated 
incorrectly because when I compare the Krn
module generated by asm to a 
dump from that image there are twelve places where
the 5-bit offset was 
forced making it different than my Krn module.

The good
news is that at least with REL, Boot, and Krn the source code 
will pretty much
assemble just as well with the stock OS9 assembler as 
with lwasm.  I think the
only changes I had to make were to add some 
equates to define the target
machine etc., manual padding (the lwasm 
appears to have an assembler directive
for this whereas asm does not), 
and maybe a couple of other very minor issues. 
Whoever is 'in charge' 
of maintaining the source files on the repo has done a
great job in 
making sure that these modules are being kept as compatible as
possible 
with the stock assembler.


Dave Philipsen


On , Dave Philipsen
wrote:
...
> However, the lwtools assembler (evidently) assembles in machine
code 
> as:
> 
> E6 00
> 
> which is the indexed addressing mode with a 5-bit
offset with the
> offset being zero.
> 

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