diff mbox series

[10/36] next-cube: move SCSI 4020 logic from next-pc device to next-scsi device

Message ID 20241023085852.1061031-11-mark.cave-ayland@ilande.co.uk (mailing list archive)
State New
Headers show
Series next-cube: more tidy-ups and improvements | expand

Commit Message

Mark Cave-Ayland Oct. 23, 2024, 8:58 a.m. UTC 
The SCSI 4020 logic refers to the offset of the SCSI CSRs within the NeXTCube
address space. Due to the previously overlapping memory regions, there were
duplicate MMIO accessors in the next.scr memory region for these registers but
now this has been resolved. This allows us to move the more complex prototype
logic into the next-scsi MMIO accessors.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
---
 hw/m68k/next-cube.c | 139 ++++++++++++++++++++------------------------
 1 file changed, 62 insertions(+), 77 deletions(-)

Comments

Thomas Huth Oct. 28, 2024, 4:22 p.m. UTC | #1 
Am Wed, 23 Oct 2024 09:58:26 +0100
schrieb Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>:

> The SCSI 4020 logic refers to the offset of the SCSI CSRs within the NeXTCube
> address space. Due to the previously overlapping memory regions, there were
> duplicate MMIO accessors in the next.scr memory region for these registers but
> now this has been resolved. This allows us to move the more complex prototype
> logic into the next-scsi MMIO accessors.
> 
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> ---
>  hw/m68k/next-cube.c | 139 ++++++++++++++++++++------------------------
>  1 file changed, 62 insertions(+), 77 deletions(-)
> 
> diff --git a/hw/m68k/next-cube.c b/hw/m68k/next-cube.c
> index 32466a425f..22da777006 100644
> --- a/hw/m68k/next-cube.c
> +++ b/hw/m68k/next-cube.c
> @@ -365,8 +365,6 @@ static const MemoryRegionOps next_mmio_ops = {
>  
>  static uint64_t next_scr_readfn(void *opaque, hwaddr addr, unsigned size)
>  {
> -    NeXTPC *s = NEXT_PC(opaque);
> -    NeXTSCSI *ns = NEXT_SCSI(&s->next_scsi);
>      uint64_t val;
>  
>      switch (addr) {
> @@ -375,16 +373,6 @@ static uint64_t next_scr_readfn(void *opaque, hwaddr addr, unsigned size)
>          val = 0x40 | 0x04 | 0x2 | 0x1;
>          break;
>  
> -    case 0x14020:
> -        DPRINTF("SCSI 4020  STATUS READ %X\n", ns->scsi_csr_1);
> -        val = ns->scsi_csr_1;
> -        break;
> -
> -    case 0x14021:
> -        DPRINTF("SCSI 4021 STATUS READ %X\n", ns->scsi_csr_2);
> -        val = 0x40;

Where is that hard-coded 0x40 gone now? Please mention this in the commit
description, otherwise this looks like a mistake?

 Thomas


> -        break;
> -
>      /*
>       * These 4 registers are the hardware timer, not sure which register
>       * is the latch instead of data, but no problems so far.
> @@ -413,9 +401,6 @@ static uint64_t next_scr_readfn(void *opaque, hwaddr addr, unsigned size)
>  static void next_scr_writefn(void *opaque, hwaddr addr, uint64_t val,
>                               unsigned size)
>  {
> -    NeXTPC *s = NEXT_PC(opaque);
> -    NeXTSCSI *ns = NEXT_SCSI(&s->next_scsi);
> -
>      switch (addr) {
>      case 0x14108:
>          DPRINTF("FDCSR Write: %"PRIx64 "\n", val);
> @@ -424,68 +409,6 @@ static void next_scr_writefn(void *opaque, hwaddr addr, uint64_t val,
>          }
>          break;
>  
> -    case 0x14020: /* SCSI Control Register */
> -        if (val & SCSICSR_FIFOFL) {
> -            DPRINTF("SCSICSR FIFO Flush\n");
> -            /* will have to add another irq to the esp if this is needed */
> -            /* esp_puflush_fifo(esp_g); */
> -        }
> -
> -        if (val & SCSICSR_ENABLE) {
> -            DPRINTF("SCSICSR Enable\n");
> -            /*
> -             * qemu_irq_raise(s->scsi_dma);
> -             * s->scsi_csr_1 = 0xc0;
> -             * s->scsi_csr_1 |= 0x1;
> -             * qemu_irq_pulse(s->scsi_dma);
> -             */
> -        }
> -        /*
> -         * else
> -         *     s->scsi_csr_1 &= ~SCSICSR_ENABLE;
> -         */
> -
> -        if (val & SCSICSR_RESET) {
> -            DPRINTF("SCSICSR Reset\n");
> -            /* I think this should set DMADIR. CPUDMA and INTMASK to 0 */
> -            qemu_irq_raise(s->scsi_reset);
> -            ns->scsi_csr_1 &= ~(SCSICSR_INTMASK | 0x80 | 0x1);
> -            qemu_irq_lower(s->scsi_reset);
> -        }
> -        if (val & SCSICSR_DMADIR) {
> -            DPRINTF("SCSICSR DMAdir\n");
> -        }
> -        if (val & SCSICSR_CPUDMA) {
> -            DPRINTF("SCSICSR CPUDMA\n");
> -            /* qemu_irq_raise(s->scsi_dma); */
> -            s->int_status |= 0x4000000;
> -        } else {
> -            /* fprintf(stderr,"SCSICSR CPUDMA disabled\n"); */
> -            s->int_status &= ~(0x4000000);
> -            /* qemu_irq_lower(s->scsi_dma); */
> -        }
> -        if (val & SCSICSR_INTMASK) {
> -            DPRINTF("SCSICSR INTMASK\n");
> -            /*
> -             * int_mask &= ~0x1000;
> -             * s->scsi_csr_1 |= val;
> -             * s->scsi_csr_1 &= ~SCSICSR_INTMASK;
> -             * if (s->scsi_queued) {
> -             *     s->scsi_queued = 0;
> -             *     next_irq(s, NEXT_SCSI_I, level);
> -             * }
> -             */
> -        } else {
> -            /* int_mask |= 0x1000; */
> -        }
> -        if (val & 0x80) {
> -            /* int_mask |= 0x1000; */
> -            /* s->scsi_csr_1 |= 0x80; */
> -        }
> -        DPRINTF("SCSICSR Write: %"PRIx64 "\n", val);
> -        /* s->scsi_csr_1 = val; */
> -        break;
> -
>      /* Hardware timer latch - not implemented yet */
>      case 0x1a000:
>      default:
> @@ -846,13 +769,73 @@ static void next_scsi_csr_write(void *opaque, hwaddr addr, uint64_t val,
>                                  unsigned size)
>  {
>      NeXTSCSI *s = NEXT_SCSI(opaque);
> +    NeXTPC *pc = NEXT_PC(container_of(s, NeXTPC, next_scsi));
>  
>      switch (addr) {
>      case 0:
> +        if (val & SCSICSR_FIFOFL) {
> +            DPRINTF("SCSICSR FIFO Flush\n");
> +            /* will have to add another irq to the esp if this is needed */
> +            /* esp_puflush_fifo(esp_g); */
> +        }
> +
> +        if (val & SCSICSR_ENABLE) {
> +            DPRINTF("SCSICSR Enable\n");
> +            /*
> +             * qemu_irq_raise(s->scsi_dma);
> +             * s->scsi_csr_1 = 0xc0;
> +             * s->scsi_csr_1 |= 0x1;
> +             * qemu_irq_pulse(s->scsi_dma);
> +             */
> +        }
> +        /*
> +         * else
> +         *     s->scsi_csr_1 &= ~SCSICSR_ENABLE;
> +         */
> +
> +        if (val & SCSICSR_RESET) {
> +            DPRINTF("SCSICSR Reset\n");
> +            /* I think this should set DMADIR. CPUDMA and INTMASK to 0 */
> +            qemu_irq_raise(pc->scsi_reset);
> +            s->scsi_csr_1 &= ~(SCSICSR_INTMASK | 0x80 | 0x1);
> +            qemu_irq_lower(pc->scsi_reset);
> +        }
> +        if (val & SCSICSR_DMADIR) {
> +            DPRINTF("SCSICSR DMAdir\n");
> +        }
> +        if (val & SCSICSR_CPUDMA) {
> +            DPRINTF("SCSICSR CPUDMA\n");
> +            /* qemu_irq_raise(s->scsi_dma); */
> +            pc->int_status |= 0x4000000;
> +        } else {
> +            /* fprintf(stderr,"SCSICSR CPUDMA disabled\n"); */
> +            pc->int_status &= ~(0x4000000);
> +            /* qemu_irq_lower(s->scsi_dma); */
> +        }
> +        if (val & SCSICSR_INTMASK) {
> +            DPRINTF("SCSICSR INTMASK\n");
> +            /*
> +             * int_mask &= ~0x1000;
> +             * s->scsi_csr_1 |= val;
> +             * s->scsi_csr_1 &= ~SCSICSR_INTMASK;
> +             * if (s->scsi_queued) {
> +             *     s->scsi_queued = 0;
> +             *     next_irq(s, NEXT_SCSI_I, level);
> +             * }
> +             */
> +        } else {
> +            /* int_mask |= 0x1000; */
> +        }
> +        if (val & 0x80) {
> +            /* int_mask |= 0x1000; */
> +            /* s->scsi_csr_1 |= 0x80; */
> +        }
> +        DPRINTF("SCSICSR1 Write: %"PRIx64 "\n", val);
>          s->scsi_csr_1 = val;
>          break;
>  
>      case 1:
> +        DPRINTF("SCSICSR2 Write: %"PRIx64 "\n", val);
>          s->scsi_csr_2 = val;
>          break;
>  
> @@ -868,10 +851,12 @@ static uint64_t next_scsi_csr_read(void *opaque, hwaddr addr, unsigned size)
>  
>      switch (addr) {
>      case 0:
> +        DPRINTF("SCSI 4020  STATUS READ %X\n", s->scsi_csr_1);
>          val = s->scsi_csr_1;
>          break;
>  
>      case 1:
> +        DPRINTF("SCSI 4021 STATUS READ %X\n", s->scsi_csr_2);
>          val = s->scsi_csr_2;
>          break;
>
Mark Cave-Ayland Oct. 28, 2024, 10:23 p.m. UTC | #2 
On 28/10/2024 16:22, Thomas Huth wrote:

> Am Wed, 23 Oct 2024 09:58:26 +0100
> schrieb Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>:
> 
>> The SCSI 4020 logic refers to the offset of the SCSI CSRs within the NeXTCube
>> address space. Due to the previously overlapping memory regions, there were
>> duplicate MMIO accessors in the next.scr memory region for these registers but
>> now this has been resolved. This allows us to move the more complex prototype
>> logic into the next-scsi MMIO accessors.
>>
>> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
>> ---
>>   hw/m68k/next-cube.c | 139 ++++++++++++++++++++------------------------
>>   1 file changed, 62 insertions(+), 77 deletions(-)
>>
>> diff --git a/hw/m68k/next-cube.c b/hw/m68k/next-cube.c
>> index 32466a425f..22da777006 100644
>> --- a/hw/m68k/next-cube.c
>> +++ b/hw/m68k/next-cube.c
>> @@ -365,8 +365,6 @@ static const MemoryRegionOps next_mmio_ops = {
>>   
>>   static uint64_t next_scr_readfn(void *opaque, hwaddr addr, unsigned size)
>>   {
>> -    NeXTPC *s = NEXT_PC(opaque);
>> -    NeXTSCSI *ns = NEXT_SCSI(&s->next_scsi);
>>       uint64_t val;
>>   
>>       switch (addr) {
>> @@ -375,16 +373,6 @@ static uint64_t next_scr_readfn(void *opaque, hwaddr addr, unsigned size)
>>           val = 0x40 | 0x04 | 0x2 | 0x1;
>>           break;
>>   
>> -    case 0x14020:
>> -        DPRINTF("SCSI 4020  STATUS READ %X\n", ns->scsi_csr_1);
>> -        val = ns->scsi_csr_1;
>> -        break;
>> -
>> -    case 0x14021:
>> -        DPRINTF("SCSI 4021 STATUS READ %X\n", ns->scsi_csr_2);
>> -        val = 0x40;
> 
> Where is that hard-coded 0x40 gone now? Please mention this in the commit
> description, otherwise this looks like a mistake?

Heh I guess the part about the duplicate MMIO accessors was a little bit too cryptic? 
I'll have a think as to how to improve the commit message for v2.


ATB,

Mark.

>> -        break;
>> -
>>       /*
>>        * These 4 registers are the hardware timer, not sure which register
>>        * is the latch instead of data, but no problems so far.
>> @@ -413,9 +401,6 @@ static uint64_t next_scr_readfn(void *opaque, hwaddr addr, unsigned size)
>>   static void next_scr_writefn(void *opaque, hwaddr addr, uint64_t val,
>>                                unsigned size)
>>   {
>> -    NeXTPC *s = NEXT_PC(opaque);
>> -    NeXTSCSI *ns = NEXT_SCSI(&s->next_scsi);
>> -
>>       switch (addr) {
>>       case 0x14108:
>>           DPRINTF("FDCSR Write: %"PRIx64 "\n", val);
>> @@ -424,68 +409,6 @@ static void next_scr_writefn(void *opaque, hwaddr addr, uint64_t val,
>>           }
>>           break;
>>   
>> -    case 0x14020: /* SCSI Control Register */
>> -        if (val & SCSICSR_FIFOFL) {
>> -            DPRINTF("SCSICSR FIFO Flush\n");
>> -            /* will have to add another irq to the esp if this is needed */
>> -            /* esp_puflush_fifo(esp_g); */
>> -        }
>> -
>> -        if (val & SCSICSR_ENABLE) {
>> -            DPRINTF("SCSICSR Enable\n");
>> -            /*
>> -             * qemu_irq_raise(s->scsi_dma);
>> -             * s->scsi_csr_1 = 0xc0;
>> -             * s->scsi_csr_1 |= 0x1;
>> -             * qemu_irq_pulse(s->scsi_dma);
>> -             */
>> -        }
>> -        /*
>> -         * else
>> -         *     s->scsi_csr_1 &= ~SCSICSR_ENABLE;
>> -         */
>> -
>> -        if (val & SCSICSR_RESET) {
>> -            DPRINTF("SCSICSR Reset\n");
>> -            /* I think this should set DMADIR. CPUDMA and INTMASK to 0 */
>> -            qemu_irq_raise(s->scsi_reset);
>> -            ns->scsi_csr_1 &= ~(SCSICSR_INTMASK | 0x80 | 0x1);
>> -            qemu_irq_lower(s->scsi_reset);
>> -        }
>> -        if (val & SCSICSR_DMADIR) {
>> -            DPRINTF("SCSICSR DMAdir\n");
>> -        }
>> -        if (val & SCSICSR_CPUDMA) {
>> -            DPRINTF("SCSICSR CPUDMA\n");
>> -            /* qemu_irq_raise(s->scsi_dma); */
>> -            s->int_status |= 0x4000000;
>> -        } else {
>> -            /* fprintf(stderr,"SCSICSR CPUDMA disabled\n"); */
>> -            s->int_status &= ~(0x4000000);
>> -            /* qemu_irq_lower(s->scsi_dma); */
>> -        }
>> -        if (val & SCSICSR_INTMASK) {
>> -            DPRINTF("SCSICSR INTMASK\n");
>> -            /*
>> -             * int_mask &= ~0x1000;
>> -             * s->scsi_csr_1 |= val;
>> -             * s->scsi_csr_1 &= ~SCSICSR_INTMASK;
>> -             * if (s->scsi_queued) {
>> -             *     s->scsi_queued = 0;
>> -             *     next_irq(s, NEXT_SCSI_I, level);
>> -             * }
>> -             */
>> -        } else {
>> -            /* int_mask |= 0x1000; */
>> -        }
>> -        if (val & 0x80) {
>> -            /* int_mask |= 0x1000; */
>> -            /* s->scsi_csr_1 |= 0x80; */
>> -        }
>> -        DPRINTF("SCSICSR Write: %"PRIx64 "\n", val);
>> -        /* s->scsi_csr_1 = val; */
>> -        break;
>> -
>>       /* Hardware timer latch - not implemented yet */
>>       case 0x1a000:
>>       default:
>> @@ -846,13 +769,73 @@ static void next_scsi_csr_write(void *opaque, hwaddr addr, uint64_t val,
>>                                   unsigned size)
>>   {
>>       NeXTSCSI *s = NEXT_SCSI(opaque);
>> +    NeXTPC *pc = NEXT_PC(container_of(s, NeXTPC, next_scsi));
>>   
>>       switch (addr) {
>>       case 0:
>> +        if (val & SCSICSR_FIFOFL) {
>> +            DPRINTF("SCSICSR FIFO Flush\n");
>> +            /* will have to add another irq to the esp if this is needed */
>> +            /* esp_puflush_fifo(esp_g); */
>> +        }
>> +
>> +        if (val & SCSICSR_ENABLE) {
>> +            DPRINTF("SCSICSR Enable\n");
>> +            /*
>> +             * qemu_irq_raise(s->scsi_dma);
>> +             * s->scsi_csr_1 = 0xc0;
>> +             * s->scsi_csr_1 |= 0x1;
>> +             * qemu_irq_pulse(s->scsi_dma);
>> +             */
>> +        }
>> +        /*
>> +         * else
>> +         *     s->scsi_csr_1 &= ~SCSICSR_ENABLE;
>> +         */
>> +
>> +        if (val & SCSICSR_RESET) {
>> +            DPRINTF("SCSICSR Reset\n");
>> +            /* I think this should set DMADIR. CPUDMA and INTMASK to 0 */
>> +            qemu_irq_raise(pc->scsi_reset);
>> +            s->scsi_csr_1 &= ~(SCSICSR_INTMASK | 0x80 | 0x1);
>> +            qemu_irq_lower(pc->scsi_reset);
>> +        }
>> +        if (val & SCSICSR_DMADIR) {
>> +            DPRINTF("SCSICSR DMAdir\n");
>> +        }
>> +        if (val & SCSICSR_CPUDMA) {
>> +            DPRINTF("SCSICSR CPUDMA\n");
>> +            /* qemu_irq_raise(s->scsi_dma); */
>> +            pc->int_status |= 0x4000000;
>> +        } else {
>> +            /* fprintf(stderr,"SCSICSR CPUDMA disabled\n"); */
>> +            pc->int_status &= ~(0x4000000);
>> +            /* qemu_irq_lower(s->scsi_dma); */
>> +        }
>> +        if (val & SCSICSR_INTMASK) {
>> +            DPRINTF("SCSICSR INTMASK\n");
>> +            /*
>> +             * int_mask &= ~0x1000;
>> +             * s->scsi_csr_1 |= val;
>> +             * s->scsi_csr_1 &= ~SCSICSR_INTMASK;
>> +             * if (s->scsi_queued) {
>> +             *     s->scsi_queued = 0;
>> +             *     next_irq(s, NEXT_SCSI_I, level);
>> +             * }
>> +             */
>> +        } else {
>> +            /* int_mask |= 0x1000; */
>> +        }
>> +        if (val & 0x80) {
>> +            /* int_mask |= 0x1000; */
>> +            /* s->scsi_csr_1 |= 0x80; */
>> +        }
>> +        DPRINTF("SCSICSR1 Write: %"PRIx64 "\n", val);
>>           s->scsi_csr_1 = val;
>>           break;
>>   
>>       case 1:
>> +        DPRINTF("SCSICSR2 Write: %"PRIx64 "\n", val);
>>           s->scsi_csr_2 = val;
>>           break;
>>   
>> @@ -868,10 +851,12 @@ static uint64_t next_scsi_csr_read(void *opaque, hwaddr addr, unsigned size)
>>   
>>       switch (addr) {
>>       case 0:
>> +        DPRINTF("SCSI 4020  STATUS READ %X\n", s->scsi_csr_1);
>>           val = s->scsi_csr_1;
>>           break;
>>   
>>       case 1:
>> +        DPRINTF("SCSI 4021 STATUS READ %X\n", s->scsi_csr_2);
>>           val = s->scsi_csr_2;
>>           break;
>>
diff mbox series

Patch

diff --git a/hw/m68k/next-cube.c b/hw/m68k/next-cube.c
index 32466a425f..22da777006 100644
--- a/hw/m68k/next-cube.c
+++ b/hw/m68k/next-cube.c
@@ -365,8 +365,6 @@  static const MemoryRegionOps next_mmio_ops = {
 
 static uint64_t next_scr_readfn(void *opaque, hwaddr addr, unsigned size)
 {
-    NeXTPC *s = NEXT_PC(opaque);
-    NeXTSCSI *ns = NEXT_SCSI(&s->next_scsi);
     uint64_t val;
 
     switch (addr) {
@@ -375,16 +373,6 @@  static uint64_t next_scr_readfn(void *opaque, hwaddr addr, unsigned size)
         val = 0x40 | 0x04 | 0x2 | 0x1;
         break;
 
-    case 0x14020:
-        DPRINTF("SCSI 4020  STATUS READ %X\n", ns->scsi_csr_1);
-        val = ns->scsi_csr_1;
-        break;
-
-    case 0x14021:
-        DPRINTF("SCSI 4021 STATUS READ %X\n", ns->scsi_csr_2);
-        val = 0x40;
-        break;
-
     /*
      * These 4 registers are the hardware timer, not sure which register
      * is the latch instead of data, but no problems so far.
@@ -413,9 +401,6 @@  static uint64_t next_scr_readfn(void *opaque, hwaddr addr, unsigned size)
 static void next_scr_writefn(void *opaque, hwaddr addr, uint64_t val,
                              unsigned size)
 {
-    NeXTPC *s = NEXT_PC(opaque);
-    NeXTSCSI *ns = NEXT_SCSI(&s->next_scsi);
-
     switch (addr) {
     case 0x14108:
         DPRINTF("FDCSR Write: %"PRIx64 "\n", val);
@@ -424,68 +409,6 @@  static void next_scr_writefn(void *opaque, hwaddr addr, uint64_t val,
         }
         break;
 
-    case 0x14020: /* SCSI Control Register */
-        if (val & SCSICSR_FIFOFL) {
-            DPRINTF("SCSICSR FIFO Flush\n");
-            /* will have to add another irq to the esp if this is needed */
-            /* esp_puflush_fifo(esp_g); */
-        }
-
-        if (val & SCSICSR_ENABLE) {
-            DPRINTF("SCSICSR Enable\n");
-            /*
-             * qemu_irq_raise(s->scsi_dma);
-             * s->scsi_csr_1 = 0xc0;
-             * s->scsi_csr_1 |= 0x1;
-             * qemu_irq_pulse(s->scsi_dma);
-             */
-        }
-        /*
-         * else
-         *     s->scsi_csr_1 &= ~SCSICSR_ENABLE;
-         */
-
-        if (val & SCSICSR_RESET) {
-            DPRINTF("SCSICSR Reset\n");
-            /* I think this should set DMADIR. CPUDMA and INTMASK to 0 */
-            qemu_irq_raise(s->scsi_reset);
-            ns->scsi_csr_1 &= ~(SCSICSR_INTMASK | 0x80 | 0x1);
-            qemu_irq_lower(s->scsi_reset);
-        }
-        if (val & SCSICSR_DMADIR) {
-            DPRINTF("SCSICSR DMAdir\n");
-        }
-        if (val & SCSICSR_CPUDMA) {
-            DPRINTF("SCSICSR CPUDMA\n");
-            /* qemu_irq_raise(s->scsi_dma); */
-            s->int_status |= 0x4000000;
-        } else {
-            /* fprintf(stderr,"SCSICSR CPUDMA disabled\n"); */
-            s->int_status &= ~(0x4000000);
-            /* qemu_irq_lower(s->scsi_dma); */
-        }
-        if (val & SCSICSR_INTMASK) {
-            DPRINTF("SCSICSR INTMASK\n");
-            /*
-             * int_mask &= ~0x1000;
-             * s->scsi_csr_1 |= val;
-             * s->scsi_csr_1 &= ~SCSICSR_INTMASK;
-             * if (s->scsi_queued) {
-             *     s->scsi_queued = 0;
-             *     next_irq(s, NEXT_SCSI_I, level);
-             * }
-             */
-        } else {
-            /* int_mask |= 0x1000; */
-        }
-        if (val & 0x80) {
-            /* int_mask |= 0x1000; */
-            /* s->scsi_csr_1 |= 0x80; */
-        }
-        DPRINTF("SCSICSR Write: %"PRIx64 "\n", val);
-        /* s->scsi_csr_1 = val; */
-        break;
-
     /* Hardware timer latch - not implemented yet */
     case 0x1a000:
     default:
@@ -846,13 +769,73 @@  static void next_scsi_csr_write(void *opaque, hwaddr addr, uint64_t val,
                                 unsigned size)
 {
     NeXTSCSI *s = NEXT_SCSI(opaque);
+    NeXTPC *pc = NEXT_PC(container_of(s, NeXTPC, next_scsi));
 
     switch (addr) {
     case 0:
+        if (val & SCSICSR_FIFOFL) {
+            DPRINTF("SCSICSR FIFO Flush\n");
+            /* will have to add another irq to the esp if this is needed */
+            /* esp_puflush_fifo(esp_g); */
+        }
+
+        if (val & SCSICSR_ENABLE) {
+            DPRINTF("SCSICSR Enable\n");
+            /*
+             * qemu_irq_raise(s->scsi_dma);
+             * s->scsi_csr_1 = 0xc0;
+             * s->scsi_csr_1 |= 0x1;
+             * qemu_irq_pulse(s->scsi_dma);
+             */
+        }
+        /*
+         * else
+         *     s->scsi_csr_1 &= ~SCSICSR_ENABLE;
+         */
+
+        if (val & SCSICSR_RESET) {
+            DPRINTF("SCSICSR Reset\n");
+            /* I think this should set DMADIR. CPUDMA and INTMASK to 0 */
+            qemu_irq_raise(pc->scsi_reset);
+            s->scsi_csr_1 &= ~(SCSICSR_INTMASK | 0x80 | 0x1);
+            qemu_irq_lower(pc->scsi_reset);
+        }
+        if (val & SCSICSR_DMADIR) {
+            DPRINTF("SCSICSR DMAdir\n");
+        }
+        if (val & SCSICSR_CPUDMA) {
+            DPRINTF("SCSICSR CPUDMA\n");
+            /* qemu_irq_raise(s->scsi_dma); */
+            pc->int_status |= 0x4000000;
+        } else {
+            /* fprintf(stderr,"SCSICSR CPUDMA disabled\n"); */
+            pc->int_status &= ~(0x4000000);
+            /* qemu_irq_lower(s->scsi_dma); */
+        }
+        if (val & SCSICSR_INTMASK) {
+            DPRINTF("SCSICSR INTMASK\n");
+            /*
+             * int_mask &= ~0x1000;
+             * s->scsi_csr_1 |= val;
+             * s->scsi_csr_1 &= ~SCSICSR_INTMASK;
+             * if (s->scsi_queued) {
+             *     s->scsi_queued = 0;
+             *     next_irq(s, NEXT_SCSI_I, level);
+             * }
+             */
+        } else {
+            /* int_mask |= 0x1000; */
+        }
+        if (val & 0x80) {
+            /* int_mask |= 0x1000; */
+            /* s->scsi_csr_1 |= 0x80; */
+        }
+        DPRINTF("SCSICSR1 Write: %"PRIx64 "\n", val);
         s->scsi_csr_1 = val;
         break;
 
     case 1:
+        DPRINTF("SCSICSR2 Write: %"PRIx64 "\n", val);
         s->scsi_csr_2 = val;
         break;
 
@@ -868,10 +851,12 @@  static uint64_t next_scsi_csr_read(void *opaque, hwaddr addr, unsigned size)
 
     switch (addr) {
     case 0:
+        DPRINTF("SCSI 4020  STATUS READ %X\n", s->scsi_csr_1);
         val = s->scsi_csr_1;
         break;
 
     case 1:
+        DPRINTF("SCSI 4021 STATUS READ %X\n", s->scsi_csr_2);
         val = s->scsi_csr_2;
         break;