Write serial port IRQ tests

[dirkwhoffmann]

I've bought a loopback adapter for the serial port which can be exploited by a program to interrupt itself by sending out UART packages. If I understood the latest cputester code correctly, Toni is using this approach for verifying IPL timing.

TODO:

• Write test cases that visualise UART IRQ timing.
• Adjust timing in vAmiga to match the real machine.

Together with AmigaTestKit, the adapter has revealed that my favourite ECS machine has a broken serial port 😕. Luckily, the OCS machine is all fine. It only had a bended pin which was easy to fix.

[dirkwhoffmann]

A first chunk of UART interrupt tests has been uploaded to the test repo.

UART/txirq0:

Amiga 500 ECS: 🥰

vAmiga: 🙈

UART/txirq1:

Amiga 500 ECS: 🥰

vAmiga: 🙈

None of the tests utilise the RBF interrupt, yet. Hence, no loopback dongle needed.

[dirkwhoffmann]

Some UART tests were broken in v2.1b2. This has been been fixed. Now all tests are passing again:

Using the UART TBE interrupt, it's possible to write fine-grained IPL tests. This one tests the MOVE Rg,Rg instruction:

In each section IPL timing affects when a color change from grey to yellow moves over to a color change from grey to light red to yellow.

vAmiga:

BTW, no dongle for the serial port is required. Originally I though that I need to utilise the RBF interrupt, but the TBE interrupt is totally sufficient.

[dirkwhoffmann]

Fixed in v2.1b3.