Re: [hatari-devel] SCU/VME register access?

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 07/06/2024 à 14:51, Eero Tamminen a écrit :
> Hi,
>
> On 5.6.2024 12.46, Nicolas Pomarède wrote:
> > 4 years later, time to resurrect this old thread :)
> >
> > Are there any ready to use linux disk image I could use to check the 
> > boot process regarding SCU registers ?
>
> If you're using Debian, it's easy to build latest m68k Linux kernel.
>
> Just copy-paste the commands given in the "3. Building m68k kernel" 
> section of the Hatari "m68k-linux.txt" doc (with "/path/to/hatari" parts 
> replaced by path to your Hatari checkout).
>
> If you do not have Debian, I can mail you the kernel and its symbols 
> file (about 5MB uncompressed).

Hi

I don't have debian, so if you can send me a ready-to-use kernel and/or 
a bootable disk image (similar to the one for SystemV that was discussed 
on atari-forum) that would save me quite some time as I don't feel like 
building a kernel at the moment :)

> Example in "6. Running Hatari" section tells how to run that Linux 
> kernel with Hatari.
>
> As TT SCU is accessed already at Linux boot, you do not need a disk 
> image i.e. you can drop the "--ide-master" option (besides replacing 
> "falcon" with "tt"). [1]
>
>
> > I know there's also the SysV disk images at http://www.atariunix.com/ 
> > but it seems they also rely on the RTC's internal timer interrupt, 
> > which is not emulated so far
> >
> > Or some other programs that modify SCU registers ? (apart from the TOS 
> > used in MegaSTE / TT)
>
> This is shown by "--trace vme" on latest m68k Linux v6.9:

I see that ; just wondering if apart from TOS, SystemV and Linux there 
were other programs known for using SCU regs ?

Nicolas

> ---------------------------------------------------
> ...
> VME: SCU read  (0xff8e01): 0x00
> ...
> NR_IRQS: 141
> VME: SCU write (0xff8e01): 0x10 (system interrupt mask)
> VME: SCU write (0xff8e0d): 0x60 (VME interrupt mask)
> clocksource: mfp: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 
> 77769386670404 ns
> unexpected interrupt from 112
> Console: colour dummy device 80x25
> printk: legacy console [tty0] enabled
> unexpected interrupt from 112
> ...
> unexpected interrupt from 104
> ...
> ---------------------------------------------------
>
> (After which there are constant messages of both 104 & 112 interrupts.)
>
>
> Whereas with "--vme off", linux boots to user-space just fine under TT 
> emulation.
>
>
>      - Eero
>
> [1] Section "4. Building root file system" gives commands for building 
> two different root file systems from packages available on Debian, one 
> based one Busybox, and another based on klibc utilities.