55 lines
2.3 KiB
Markdown
55 lines
2.3 KiB
Markdown
---
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layout: page
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title: PC Trace Utility
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permalink: /tests/pc/trace/
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---
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WARNING: This utility is obsolete. It has been superseded by [test386](/tests/pc/80386/),
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which, going forward, serves as our new model for instruction-level testing. As a result,
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the **traceLog()** functionality mentioned below has been removed from the PCjs source code
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(but you can always dig it back up if you really want it).
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Overview
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---
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TRACE.COM takes an instruction log, as recorded by the PCjs Debugger's traceLog() function, and
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"plays" the instructions back on another machine DOS-compatible 8086 machine, verifying that:
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1. Results match the recorded results;
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2. Any "modified" flags match the recorded flags; and
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3. Any "unmodified" flags remain unmodified
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The format of an instruction log entry is a series of lines (ASCII characters terminated by an LF),
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where each line looks like:
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F000:EEFF SHL(0480,0002,F006) 1200,F006
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specifically:
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address, space, instruction, parenthesis, dst operand, comma, src operand, comma,
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input flags, parenthesis, space, result, comma, and output flags
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WARNING: For the shift and rotate tests to pass on a real x86 CPU, we either have to distinguish
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between single-bit shifts and multi-bit shifts (because the latter leaves PS_OF in an "undefined"
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state), or we have to ignore PS_OF altogether. For now, I'm specifying PS_ALL_BUT_OF for those
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instructions, even though we'll be missing OVERFLOW validation for all single-bit shifts and rotates.
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Operation
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---
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To load TRACE.COM and TRACE.TXT onto a virtual disk image that PCjs can access, you can add an
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"automount" setting to your PCjs <fdc> configuration that will dynamically generate a fresh disk image
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every time the machine is loaded, via the DiskDump API. This is useful when you're constantly
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generating new test results:
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<fdc id="fdcNEC" automount='{B:{name:"Trace Tests",path:"/tests/pc/trace/trace.com;trace.txt"}}'/>
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Alternatively, if you want to run the tests in another virtual PC environment (eg, VMware Fusion),
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you can create an IMG disk image from a directory using DiskDump's command-line interface:
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cd ~/Sites/pcjs/tests/pc
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node ~/Sites/pcjs/modules/diskdump/bin/diskdump --dir=trace --format=img --output=trace.img
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OS X users can also create an ISO image like so:
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hdiutil makehybrid -o ~/Sites/pcjs/tests/pc/trace.iso ~/Sites/pcjs/tests/pc/trace -iso -joliet
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