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From: ian@sibyl.eleceng.ua.oz.au
Newsgroups: comp.sys.nsc.32k
Subject: Monitor questions
Message-ID: <9005081634.2213@munnari.oz.au>
Date: 8 May 90 06:32:27 GMT
Sender: news@daver.bungi.com
Lines: 22
Approved: news@daver.bungi.com

Well, I have just been trying to compile Bruce's monitor using gcc/gas/gld.
Not too bad. I have written a sed script to convert between Bruce's assembler
syntax and gas. This is not too hard because the addressing modes syntax is
the same. I have a couple of questions about the semantics of the pseudo-ops
though. What does ".program" and ".static" do? I have assumed they are
the same as ".text" and ".data" is that right?

Gnu ld does not define _bdata. I am currently linking in a little
assembler first.s which defines _bdata to be the pc for the bottom of
the .data section. Does that sound right?

Bruce uses a -D option for your linker. The GNU ld also takes a -D
option but I suspect the semantics are different. The GNU loader used
-Tdata to specify the starting address of the data section and -D
specifies the *size* of the data section. I *think* -Tdata is the
one to use.

One thing I don't understand is what use a .data section is in the
context of a rom monitor. RAM will be uninitialized and ROM is
unalterable. Constant data can be put in the .text segment (and end up
in ROM) and any non constant data will have to be initialized and
might as well be in the .bss segment.