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6502bench/SourceGen/RuntimeData
Andy McFadden 99cd0d3ac1 Improve handling of C64 PRG header
C64 PRG files are pretty common.  Their salient feature is that they
start with a 16-bit value that is used as the load address.  The
value is commonly generated by the assembler itself, rather than
explicitly added to the source file.

Not all assemblers know what a PRG file is, and some of them handle
it in ways that are difficult to guarantee in SourceGen.  ACME adds
the 16-bit header when the output file name ends in ".prg", cc65
uses a modified config file, 64tass uses a different command-line
option, and Merlin 32 has no idea what they are.

This change adds PRG file detection and handling to the 64tass code
generator.  Doing so required making a few changes to the gen/asm
interfaces, because we now need to have the generator pass additional
flags to the assembler, and sometimes we need code generation to
start somewhere other than offset zero.  Overall the changes were
pretty minor.

The 20042-address-changes test needed a 6502-only variant.  A new test
(20040-address-changes) has been added and given a PRG header.  As
part of this change the 65816 variant was changed to use addresses
in bank 2, which uncovered a code generation bug that this change
also fixes.

The 64tass --long-address flag doesn't appear to be necessary for
files <= 65536 bytes long, so we no longer emit it for those.

(issue #90)
2020-10-17 16:45:13 -07:00
..
Apple Update Apple /// SOS definitions 2020-08-22 18:41:24 -07:00
Atari Add simple SGEC reader 2020-04-13 17:33:34 -07:00
Commodore Various minor tweaks 2019-12-07 11:42:26 -08:00
Help Improve handling of C64 PRG header 2020-10-17 16:45:13 -07:00
Nintendo Add NES visualization generator 2020-05-14 15:34:05 -07:00
TestData Initial file commit 2018-09-28 10:05:11 -07:00
ExportTemplate.html Minor style change to "back" link 2020-09-04 18:17:01 -07:00
LegalStuff.txt Mention VS2017 icon library usage 2020-09-04 18:20:26 -07:00
README.md Updated the RuntimeData README 2020-01-01 18:06:59 -08:00
RuntimeData.csproj Initial file commit 2018-09-28 10:05:11 -07:00
SGStyle.css Add visualization sets to exported HTML 2019-12-13 17:15:38 -08:00
SystemDefs.json Add W65C02S support, part 2 2020-10-10 18:34:19 -07:00

Runtime Data

Symbol files and analyzer scripts are split into directories by platform manufacturer.

The Visual Studio project (RuntimeData.csproj) exists so you can edit scripts with IntelliSense and error highlighting. Everything here is distributed as source, not in compiled form; all compilation occurs at run time.

SystemDefs.json

This file defines the systems available in the "new project" screen. The following fields are mandatory:

  • Name - Short name that identifies the system.
  • GroupName - Short string used to group common items together in the UI.
  • CPU - Type of CPU used. The string must be part of the known set (see CpuDef.cs)
  • Speed - Clock rate, in MHz, of the CPU on the system. When multiple speeds are possible, use the most common, favoring NTSC over PAL.
  • SymbolFiles - List of platform symbol file identifiers (see below).
  • ExtensionScripts - List of extension script file identifiers (see below).
  • Parameters - List of optional parameters (see below).

The currently-supported parameters are:

  • load-address=<addr> - Specify the initial load address. The default is 0x1000.
  • entry-flags=<flag-set> - Specify the processor status flag values to use at entry points. This is intended for use on the 65802/65816, and may be one of "emulation", "native-short", and "native-long". The default is "emulation".
  • undocumented-opcodes={true|false} - Enable or disable undocumented opcodes. They are disabled by default.
  • first-word-is-load-addr={true|false} - If true, the first two bytes of the file contain the load address.
  • default-text-encoding=<mode> - Specify default character encoding. Use "c64-petscii" for PETSCII. The default is low/high ASCII.

All of these things can be changed after the project has begun, but it's nice to have them configured in advance.

SymbolFiles and ExtensionScripts use file identifiers, which look like "RT:Apple/ProDOS8.sym65". The "RT:" means that the file lives in the RuntimeData directory, and the rest is a partial pathname. Files that live in the same directory as the project file are prefixed with "PROJ:". All symbol files and extension scripts must live in the RuntimeData directory or project file directory, or they will not be loaded.

All "RT:" identifier paths are relative to the RuntimeData directory. The Group Name is not automatically added.

Platform Symbol Files and Extension Scripts

These are described in the "Advanced Topics" section of the manual (here).

Misc Files

ExportTemplate.html and SGStyle.css are used by SourceGen's HTML export feature.

LegalStuff.txt is displayed in the About box.