Re: [PATCH 09/12] next-cube.c: move static old_scr2 variable to NeXTPC

[Mark Cave-Ayland]

On 16/12/2023 20:18, Thomas Huth wrote:

> Am Fri, 15 Dec 2023 20:00:06 +0000
> schrieb Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>:
>
> > Move the old_scr2 variable to NeXTPC so that the old SCR2 register state is
> > stored along with the current SCR2 state.
> >
> > Since the SCR2 register is 32-bits wide, convert old_scr2 to uint32_t and
> > update the SCR2 register access code to allow unaligned writes.
> >
> > Note that this is a migration break, but as nothing will currently boot then
> > we do not need to worry about this now.
> >
> > Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> > ---
> >   hw/m68k/next-cube.c | 12 +++++++++---
> >   1 file changed, 9 insertions(+), 3 deletions(-)
> >
> > diff --git a/hw/m68k/next-cube.c b/hw/m68k/next-cube.c
> > index 7ffd1c412e..fd707b4b54 100644
> > --- a/hw/m68k/next-cube.c
> > +++ b/hw/m68k/next-cube.c
> > @@ -91,6 +91,7 @@ struct NeXTPC {
> >   
> >       uint32_t scr1;
> >       uint32_t scr2;
> > +    uint32_t old_scr2;
> >       uint32_t int_mask;
> >       uint32_t int_status;
> >       uint32_t led;
> > @@ -137,8 +138,7 @@ static void next_scr2_led_update(NeXTPC *s)
> >   
> >   static void nextscr2_write(NeXTPC *s, uint32_t val, int size)
> >   {
> > -    static uint8_t old_scr2;
> > -    uint8_t scr2_2;
> > +    uint8_t old_scr2, scr2_2;
> >       NextRtc *rtc = &s->rtc;
> >   
> >       if (size == 4) {
> > @@ -147,6 +147,8 @@ static void nextscr2_write(NeXTPC *s, uint32_t val, int 
> > size)
> >           scr2_2 = val & 0xFF;
> >       }
> >   
> > +    old_scr2 = (s->old_scr2 >> 8) & 0xff;
> > +
> >       if (scr2_2 & 0x1) {
> >           /* DPRINTF("RTC %x phase %i\n", scr2_2, rtc->phase); */
> >           if (rtc->phase == -1) {
> > @@ -255,7 +257,6 @@ static void nextscr2_write(NeXTPC *s, uint32_t val, int 
> > size)
> >       }
> >       s->scr2 = val & 0xFFFF00FF;
> >       s->scr2 |= scr2_2 << 8;
> > -    old_scr2 = scr2_2;
> >   }
> >   
> >   static uint64_t next_mmio_read(void *opaque, hwaddr addr, unsigned size)
> > @@ -321,8 +322,11 @@ static void next_mmio_write(void *opaque, hwaddr addr, 
> > uint64_t val,
> >           break;
> >   
> >       case 0xd000 ... 0xd003:
> > +        s->scr2 = deposit32(s->scr2, (4 - (addr - 0xd000) - size) << 3,
> > +                            size << 3, val);
> >           next_scr2_led_update(s);
> >           nextscr2_write(s, val, size);
> > +        s->old_scr2 = s->scr2;
> >           break;
>
> Ah, I see, now you set s->scr2 here already ... I think you should swap the
> order of the patches 08 and 09...?

Yeah I think that would work, I'll give it a go.


ATB,

Mark.