68000 CPU tests for CD-i

Based on the file MC68000_test_all_opcodes.X68 from MicroCoreLabs MC68000_Test_Code project.

The source code has been modified to work with the Microware OS-9 assembler.

It was also converted into a CD-i system ROM image suitable for running on a CD-i emulator or on actual CD-i hardware by downloading it into RAM using CD-i Link.

Versions

There are three versions of the test:

cputest is the basic 68000 cpu test, suitable for emulator testing. It loops on the first failed test.

cpudiag is the same test but modified for diagnostic output. It displays a START message, followed by the name of each failed test, ending with an ALL_DONE message. All output is sent to the 68070 on-chip serial port.

cpufull runs the full test, suitable for trace generation. It will ignore all test failures and end with a stop instruction.

Building

For each test, a Windows .bat batch file is included to build the binary output files.

1. For tests other then the basic cputest, the batch file starts with building the corresponding assembly .s source file from cputest.s using a GNU AWK .awk script file.
2. The Microware OS-9 Assembler r68 is then run to producate a relocatable .r object file and an assembly .lst listing file.
3. Next the Microware OS-9 Linker l68 is run to create .rom files based at addresses 0x180000 (usable on Mini/Maxi-MMC CD-i players) and 0x400000 (usable on Mono-based players). A symbol .map file is also produced.
4. For cpudiag a downloadable .mod file based at address 0x8000 is also produced. This file can be downloaded into a CD-i player with the following CD-i Link command:
   cdilink -w -n -a 8000 -d cpudiag.mod -x 8400 -t

Caveats

No CD-i hardware or emulator currently passes all of the tests; the failures are all in the verification of the condition code register contents. There are probably issues with both the test and the emulators, but it's hard to fix this as the failing tests run large numbers of test instructions combining the resulting condition codes and only verify the combined result.

The only way to get this fixed is verification of a full instruction trace (such as generated by the cpufull test) on actual hardware to find out which exact condition code bits on which instruction(s) fail the test.

Discussion

Discussion of these tests belongs in the #homebrow-and-dev channel of the Philips CD-i Community Discord server.