Re: [hatari-devel] Wrong bus error stack frame with 68000 and JSR

[Toni Wilen <twilen@xxxxxxxxxx>]

>This instruction variant should have been detected by the tester (only situations that I

>can't test are absolute short addressing modes because external device can only generate

>bus errors in address range that does not include low and high 32k)

Could you check if all JSR addressing modes have same behavior? (PC not yet updated if prefetch causes bus error)

It is quite common that some addressing modes work totally differently.

(I'd like to have some details before testing, hopefully next weekend)

---

From: Toni Wilen <twilen@xxxxxxxxxx>
Sent: 20 March 2024 10:57
To: Nicolas Pomarède <npomarede@xxxxxxxxxxxx>; hatari-devel@xxxxxxxxxxxxxxxxxxx <hatari-devel@xxxxxxxxxxxxxxxxxxx>; Christian Zietz <czietz@xxxxxxx>
Subject: Re: [hatari-devel] Wrong bus error stack frame with 68000 and JSR

 

Hi

>thanks for your test, this look indeed like an error.
>
>Toni has written a rather extensive "cpu validator" program that runs on
>real amiga and on WinUAE and by comparing real HW vs emulation this
>helped in the past finding non correctly emulated features (such as
>undocumented behaviour for ZCNV bits, wrong value on the stack and so on)
>
>But as Amiga doesn't really use bus error (except for some external
>board), it's quite possible some cases were missed.

This instruction variant should have been detected by the tester (only situations that I can't test are absolute short addressing modes because external device can only generate bus errors in address range that does not include low and high 32k)

I'll retest soon.