mirror of
https://github.com/cc65/cc65.git
synced 2024-11-17 09:07:32 +00:00
169 lines
5.2 KiB
Plaintext
169 lines
5.2 KiB
Plaintext
<!doctype linuxdoc system>
|
|
|
|
<article>
|
|
|
|
<title>Using VICE with cc65
|
|
<author>Ullrich von Bassewitz, <htmlurl url="mailto:uz@cc65.org" name="uz@cc65.org">
|
|
<date>03.12.2000
|
|
|
|
<abstract>
|
|
How to debug your code using the VICE emulator.
|
|
</abstract>
|
|
|
|
<!-- Table of contents -->
|
|
<toc>
|
|
|
|
<!-- Begin the document -->
|
|
|
|
<sect>Overview<p>
|
|
|
|
This document describes how to debug your programs using the cc65 development
|
|
tools and the VICE CBM emulator.
|
|
|
|
|
|
|
|
<sect>What is VICE?<p>
|
|
|
|
VICE is an emulator for many of the CBM machines. It runs on Unix, DOS and
|
|
Windows 95. It emulates the Commodore 64, 128, VIC20, PET and the 600/700
|
|
machines. For more information see the VICE home page:
|
|
|
|
<htmlurl url="http://www.cs.cmu.edu/~dsladic/vice/vice.html"
|
|
name="http://www.cs.cmu.edu/~dsladic/vice/vice.html">
|
|
|
|
VICE has a builtin machine language monitor that may be used for debugging
|
|
your programs. Using an emulator for debugging has some advantages:
|
|
|
|
<itemize>
|
|
|
|
<item>Since you're using a crossassembler/-compiler anyway, you don't need to
|
|
transfer the program to the real machine until it is done.
|
|
|
|
<item>An emulator allows many things that are almost impossible one of the
|
|
original machines. You may set watchpoints (detect read or write access to
|
|
arbitary addresses), debug interrupt handlers and even debug routines that run
|
|
inside the 1541 floppy.
|
|
|
|
<item>You may use the label file generated by the linker to make much more use
|
|
from the monitor.
|
|
|
|
</itemize>
|
|
|
|
Please note that you need at least VICE version 0.16 for the label file
|
|
feature to work. This version has still some problems (see <ref id="problems"
|
|
name="Problems and workarounds">), but older versions had even more problems
|
|
and do <em/not/ work correctly.
|
|
|
|
|
|
|
|
<sect>How to prepare your programs<p>
|
|
|
|
VICE support is mostly done via a label file that is generated by the linker
|
|
and that may be read by the VICE monitor, so it knows about your program.
|
|
Source level debugging is <tt/not/ available, you have to debug your programs
|
|
in the assembler view.
|
|
|
|
The first step is to generate object files that contain information about
|
|
<em/all/ labels in your sources, not just the exported ones. This can be done
|
|
by several means:
|
|
|
|
<itemize>
|
|
|
|
<item>Use the -g switch on the assembler command line.
|
|
|
|
<item>Use the
|
|
<tscreen><verb>
|
|
.debuginfo +
|
|
</verb></tscreen>
|
|
command in your source.
|
|
|
|
<item>Use the <tt/-g/ switch when invoking the compiler. The compiler will
|
|
then place a <tt/.debuginfo/ command into the generated assembler source.
|
|
|
|
</itemize>
|
|
|
|
So, if you have just C code, all you need is to invoke the compiler with
|
|
<tt/-g/. If you're using assembler code, you have to use <tt/-g/ for the
|
|
assembler, or add "<tt/.debuginfo on/" to your source files. Since the
|
|
generated debug info is not appended to the generated executables, it is a
|
|
good idea to always use <tt/-g/. It makes the object files and libraries
|
|
slightly larger (˜30%), but this is usually not a problem.
|
|
|
|
The second step is to tell the linker that it should generate a VICE label
|
|
file. This is done by the <tt/-L/ switch followed by the name of the label
|
|
file (I'm usually using a <tt/.lbl/ extension for these files). An example for
|
|
a linker command line would be:
|
|
|
|
<tscreen><verb>
|
|
ld65 -t c64 -L hello.lbl -m hello.map -o hello crt0 hello.o c64.lib
|
|
</verb></tscreen>
|
|
|
|
This will generate a file named hello.lbl that contains all symbols used in
|
|
your program.
|
|
|
|
<bf>Note</bf>: The runtime libraries and startup files were generated with
|
|
debug info, so you don't have to care about this.
|
|
|
|
|
|
|
|
<sect>How to use the label file<p>
|
|
|
|
Load your program, then enter the monitor and use the "<tt/ll/" command to
|
|
load your label file like this:
|
|
|
|
<tscreen><verb>
|
|
ll "hello.lbl"
|
|
</verb></tscreen>
|
|
|
|
You will get lots of warnings and even a few errors. You may ignore safely all
|
|
these warnings and errors as long as they reference any problems VICE thinks
|
|
it has with the labels.
|
|
|
|
After loading the labels, they are used by VICE in the disassembler listing,
|
|
and you may use them whereever you need to specify an address. Try
|
|
|
|
<tscreen><verb>
|
|
d ._main
|
|
</verb></tscreen>
|
|
|
|
as an example (note that VICE needs a leading dot before all labels, and that
|
|
the compiler prepends an underline under most named labels).
|
|
|
|
|
|
|
|
<sect>Problems and workarounds<label id="problems"><p>
|
|
|
|
Older versions of VICE had several problems with labels. However, even those
|
|
versions were still tremendously useful, and all known problems are gone in
|
|
current versions. So, here is a list of the problems known to me as of version
|
|
0.16.1:
|
|
|
|
<itemize>
|
|
|
|
<item>The "<tt/ll/" command does not work. Worse, it seems that internal
|
|
memory gets corrupted when using this command, so VICE will crash after use.
|
|
Use the "<tt/pb/" command to load the label file in this case.
|
|
|
|
<item>VICE will crash if you use a label that is undefined. This is probably
|
|
the worst problem of all, since it needs just one typo to kill VICE. So, watch
|
|
your steps:-)
|
|
|
|
<item>Cheap labels, that is, labels starting with '@' or '?' are not accepted.
|
|
|
|
<item>The disassembly output is somewhat suboptimal. However, most things are
|
|
just cosmetical, e.g. labels appended to the right side of the disassembled
|
|
code.
|
|
|
|
</itemize>
|
|
|
|
<bf>Note</bf>: All these problems are fixed in current (>= 1.0) VICE
|
|
versions. If you're really using such an old version, you should think about
|
|
an upgrade.
|
|
|
|
|
|
|
|
</article>
|
|
|
|
|
|
|