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From: deller@kernel.org
To: qemu-devel@nongnu.org, Richard Henderson <richard.henderson@linaro.org>
Cc: Helge Deller <deller@gmx.de>,
	Soumyajyotii Ssarkar <soumyajyotisarkar23@gmail.com>
Subject: [PATCH 02/10] ncr710: Add driver for the NCR 53c710 SCSI chip
Date: Fri, 17 Oct 2025 22:06:45 +0200	[thread overview]
Message-ID: <20251017200653.23337-3-deller@kernel.org> (raw)
In-Reply-To: <20251017200653.23337-1-deller@kernel.org>

From: Soumyajyotii Ssarkar <soumyajyotisarkar23@gmail.com>

Add an emulation for the NCR 53c710 SCSI chip.
This SCSI chip was used widely in historic machines, e.g. as SCSI core
in the LASI controller in HP PA-RISC machines.

This driver was developed during the Google Summer of Code 2025 program.

Signed-off-by: Soumyajyotii Ssarkar <soumyajyotisarkar23@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
---
 hw/scsi/lasi_ncr710.c |  303 +++++
 hw/scsi/lasi_ncr710.h |   53 +
 hw/scsi/ncr53c710.c   | 2477 +++++++++++++++++++++++++++++++++++++++++
 hw/scsi/ncr53c710.h   |  270 +++++
 hw/scsi/trace-events  |   33 +
 5 files changed, 3136 insertions(+)
 create mode 100644 hw/scsi/lasi_ncr710.c
 create mode 100644 hw/scsi/lasi_ncr710.h
 create mode 100644 hw/scsi/ncr53c710.c
 create mode 100644 hw/scsi/ncr53c710.h

diff --git a/hw/scsi/lasi_ncr710.c b/hw/scsi/lasi_ncr710.c
new file mode 100644
index 0000000000..1ca98dd72f
--- /dev/null
+++ b/hw/scsi/lasi_ncr710.c
@@ -0,0 +1,303 @@
+/*
+ * LASI Wrapper for NCR710 SCSI I/O Processor
+ *
+ * Copyright (c) 2025 Soumyajyotii Ssarkar <soumyajyotisarkar23@gmail.com>
+ * This driver was developed during the Google Summer of Code 2025 program.
+ * Mentored by Helge Deller <deller@gmx.de>
+ *
+ * NCR710 SCSI I/O Processor implementation
+ * Based on the NCR53C710 Technical Manual Version 3.2, December 2000
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/scsi/lasi_ncr710.h"
+#include "hw/scsi/ncr53c710.h"
+#include "hw/sysbus.h"
+#include "qemu/timer.h"
+#include "qemu/log.h"
+#include "trace.h"
+#include "system/blockdev.h"
+#include "migration/vmstate.h"
+#include "qapi/error.h"
+#include "system/dma.h"
+
+#define HPHW_FIO    5           /* Fixed I/O module */
+#define LASI_710_SVERSION    0x00082
+#define SCNR                 0xBEEFBABE
+#define LASI_710_HVERSION       0x3D
+
+static uint64_t lasi_ncr710_reg_read(void *opaque, hwaddr addr,
+                                    unsigned size)
+{
+    LasiNCR710State *s = LASI_NCR710(opaque);
+    uint64_t val = 0;
+
+    trace_lasi_ncr710_reg_read(addr, 0, size);
+
+    if (addr == 0x00) {  /* Device ID */
+        val = (HPHW_FIO << 24) | LASI_710_SVERSION;
+        trace_lasi_ncr710_reg_read_id(HPHW_FIO, LASI_710_SVERSION, val);
+        return val;
+    }
+
+    if (addr == 0x08) {  /* HVersion */
+        val = LASI_710_HVERSION;
+        trace_lasi_ncr710_reg_read_hversion(val);
+        return val;
+    }
+
+    if (addr >= 0x100) {
+        hwaddr ncr_addr = addr - 0x100;
+        if (size == 1) {
+            ncr_addr ^= 3;
+             NCR710_DPRINTF("Reading value to LASI WRAPPER == 0x%lx%s, val=0x%lx, size=%u\n",
+                   addr - 0x100, size == 1 ? " (XORed)" : "", val, size);
+            val = ncr710_reg_read(&s->ncr710, ncr_addr, size);
+        } else {
+            val = 0;
+            for (unsigned i = 0; i < size; i++) {
+                uint8_t byte_val = ncr710_reg_read(&s->ncr710, ncr_addr + i, 1);
+                val |= ((uint64_t)byte_val) << (i * 8);
+                 NCR710_DPRINTF("  Read byte %u from NCR addr 0x%lx: 0x%02x\n",
+                       i, ncr_addr + i, byte_val);
+            }
+             NCR710_DPRINTF("  Reconstructed %u-byte value: 0x%lx\n", size, val);
+        }
+
+        trace_lasi_ncr710_reg_forward_read(addr, val);
+    } else {
+        val = 0;
+        trace_lasi_ncr710_reg_read(addr, val, size);
+    }
+    return val;
+}
+
+static void lasi_ncr710_reg_write(void *opaque, hwaddr addr, uint64_t val, unsigned size)
+{
+    LasiNCR710State *s = LASI_NCR710(opaque);
+
+    trace_lasi_ncr710_reg_write(addr, val, size);
+
+    if (addr <= 0x0F) {
+        return;
+    }
+
+    if (addr >= 0x100) {
+        hwaddr ncr_addr = addr - 0x100;
+
+        if (size == 1) {
+            ncr_addr ^= 3;
+             NCR710_DPRINTF("Writing value to LASI WRAPPER == 0x%lx%s, val=0x%lx, size=%u\n",
+                   addr - 0x100, size == 1 ? " (XORed)" : "", val, size);
+            ncr710_reg_write(&s->ncr710, ncr_addr, val, size);
+        } else {
+            for (unsigned i = 0; i < size; i++) {
+                uint8_t byte_val = (val >> (i * 8)) & 0xff;
+                 NCR710_DPRINTF("  Writing byte %u to NCR addr 0x%lx: 0x%02x\n",
+                       i, ncr_addr + i, byte_val);
+                ncr710_reg_write(&s->ncr710, ncr_addr + i, byte_val, 1);
+            }
+        }
+
+        trace_lasi_ncr710_reg_forward_write(addr, val);
+    } else {
+        trace_lasi_ncr710_reg_write(addr, val, size);
+    }
+}
+
+/* req_cancelled, command_complete, transfer data forward to its
+ * core coutner part
+ */
+static void lasi_ncr710_request_cancelled(SCSIRequest *req)
+{
+    trace_lasi_ncr710_request_cancelled(req);
+    ncr710_request_cancelled(req);
+}
+
+static void lasi_ncr710_command_complete(SCSIRequest *req, size_t resid)
+{
+    const char *status_name = "UNKNOWN";
+    switch (req->status) {
+        case 0x00: status_name = "GOOD"; break;
+        case 0x02: status_name = "CHECK_CONDITION"; break;
+        case 0x04: status_name = "CONDITION_MET"; break;
+        case 0x08: status_name = "BUSY"; break;
+        case 0x10: status_name = "INTERMEDIATE"; break;
+        case 0x14: status_name = "INTERMEDIATE_CONDITION_MET"; break;
+        case 0x18: status_name = "RESERVATION_CONFLICT"; break;
+        case 0x22: status_name = "COMMAND_TERMINATED"; break;
+        case 0x28: status_name = "TASK_SET_FULL"; break;
+        default: break;
+    }
+
+    trace_lasi_ncr710_command_complete(req->status, status_name, resid);
+    ncr710_command_complete(req, resid);
+}
+
+ static void lasi_ncr710_transfer_data(SCSIRequest *req, uint32_t len)
+{
+    trace_lasi_ncr710_transfer_data(len);
+    ncr710_transfer_data(req, len);
+}
+
+static const struct SCSIBusInfo lasi_ncr710_scsi_info = {
+    .tcq = true,
+    .max_target = 8,
+    .max_lun = 0,  /* LUN support buggy, eh? */
+
+    .transfer_data = lasi_ncr710_transfer_data,
+    .complete = lasi_ncr710_command_complete,
+    .cancel = lasi_ncr710_request_cancelled,
+};
+
+static const MemoryRegionOps lasi_ncr710_mmio_ops = {
+    .read = lasi_ncr710_reg_read,
+    .write = lasi_ncr710_reg_write,
+    .endianness = DEVICE_BIG_ENDIAN,
+    .valid = {
+        .min_access_size = 1,
+        .max_access_size = 4,
+    },
+};
+
+static const VMStateDescription vmstate_lasi_ncr710 = {
+    .name = "lasi-ncr710",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (const VMStateField[]) {
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void lasi_ncr710_realize(DeviceState *dev, Error **errp)
+{
+    LasiNCR710State *s = LASI_NCR710(dev);
+    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
+
+    trace_lasi_ncr710_device_realize();
+
+    memset(&s->ncr710, 0, sizeof(s->ncr710));
+    scsi_bus_init(&s->ncr710.bus, sizeof(s->ncr710.bus), dev, &lasi_ncr710_scsi_info);
+    s->ncr710.as = &address_space_memory;
+
+    /* Set up NCR710 default register values */
+    s->ncr710.scntl0 = 0xc0;
+    s->ncr710.scid = 0x80;
+    s->ncr710.dstat = NCR710_DSTAT_DFE;
+    s->ncr710.dien = 0x04;
+    s->ncr710.ctest2 = NCR710_CTEST2_DACK;
+    s->ncr710.irq = s->lasi_irq;
+
+    s->ncr710.script_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
+                                         ncr710_script_timer_callback,
+                                         &s->ncr710);
+    s->ncr710.completion_irq_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
+                                                  ncr710_completion_irq_callback,
+                                                  &s->ncr710);
+    s->ncr710.reselection_retry_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
+                                                     ncr710_reselection_retry_callback,
+                                                     &s->ncr710);
+
+    trace_lasi_ncr710_timers_initialized((uint64_t)s->ncr710.script_timer,
+                                        (uint64_t)s->ncr710.completion_irq_timer,
+                                        (uint64_t)s->ncr710.reselection_retry_timer);
+
+    /* Initialize memory region */
+    memory_region_init_io(&s->mmio, OBJECT(dev), &lasi_ncr710_mmio_ops, s, "lasi-ncr710", 0x200);
+    sysbus_init_mmio(sbd, &s->mmio);
+}
+
+void lasi_ncr710_handle_legacy_cmdline(DeviceState *lasi_dev)
+{
+    LasiNCR710State *s = LASI_NCR710(lasi_dev);
+    SCSIBus *bus = &s->ncr710.bus;
+    int found_drives = 0;
+
+    if (!bus) {
+        return;
+    }
+
+    for (int unit = 0; unit <= 7; unit++) {
+        DriveInfo *dinfo = drive_get(IF_SCSI, bus->busnr, unit);
+        if (dinfo) {
+            trace_lasi_ncr710_legacy_drive_found(bus->busnr, unit);
+            found_drives++;
+        }
+    }
+
+    trace_lasi_ncr710_handle_legacy_cmdline(bus->busnr, found_drives);
+
+    scsi_bus_legacy_handle_cmdline(bus);
+    BusChild *kid;
+    QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) {
+        trace_lasi_ncr710_scsi_device_created(object_get_typename(OBJECT(kid->child)));
+    }
+}
+
+DeviceState *lasi_ncr710_init(MemoryRegion *addr_space, hwaddr hpa, qemu_irq irq)
+{
+    DeviceState *dev;
+    LasiNCR710State *s;
+    SysBusDevice *sbd;
+
+    dev = qdev_new(TYPE_LASI_NCR710);
+    s = LASI_NCR710(dev);
+    sbd = SYS_BUS_DEVICE(dev);
+    s->lasi_irq = irq;
+    sysbus_realize_and_unref(sbd, &error_fatal);
+    memory_region_add_subregion(addr_space, hpa,
+                               sysbus_mmio_get_region(sbd, 0));
+    return dev;
+}
+
+static void lasi_ncr710_reset(DeviceState *dev)
+{
+    LasiNCR710State *s = LASI_NCR710(dev);
+    trace_lasi_ncr710_device_reset();
+    ncr710_soft_reset(&s->ncr710);
+}
+
+static void lasi_ncr710_instance_init(Object *obj)
+{
+    LasiNCR710State *s = LASI_NCR710(obj);
+
+    s->hw_type = HPHW_FIO;
+    s->sversion = LASI_710_SVERSION;
+    s->hversion = LASI_710_HVERSION;
+
+    memset(&s->ncr710, 0, sizeof(s->ncr710));
+}
+
+static void lasi_ncr710_class_init(ObjectClass *klass, const void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = lasi_ncr710_realize;
+    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
+    dc->fw_name = "scsi";
+    dc->desc = "HP-PARISC LASI NCR710 SCSI adapter";
+    device_class_set_legacy_reset(dc, lasi_ncr710_reset);
+    dc->vmsd = &vmstate_lasi_ncr710;
+    dc->user_creatable = false;
+}
+
+static const TypeInfo lasi_ncr710_info = {
+    .name          = TYPE_LASI_NCR710,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(LasiNCR710State),
+    .instance_init = lasi_ncr710_instance_init,
+    .class_init    = lasi_ncr710_class_init,
+};
+
+static void lasi_ncr710_register_types(void)
+{
+    type_register_static(&lasi_ncr710_info);
+}
+
+type_init(lasi_ncr710_register_types)
diff --git a/hw/scsi/lasi_ncr710.h b/hw/scsi/lasi_ncr710.h
new file mode 100644
index 0000000000..7565bb1480
--- /dev/null
+++ b/hw/scsi/lasi_ncr710.h
@@ -0,0 +1,53 @@
+/*
+ * LASI NCR53C710 SCSI Host Adapter
+ */
+
+#ifndef HW_LASI_NCR710_H
+#define HW_LASI_NCR710_H
+
+#include "hw/sysbus.h"
+#include "qemu/osdep.h"
+#include "exec/memattrs.h"
+#include "hw/scsi/scsi.h"
+#include "hw/scsi/ncr53c710.h"
+
+#define TYPE_LASI_NCR710 "lasi-ncr710"
+OBJECT_DECLARE_SIMPLE_TYPE(LasiNCR710State, LASI_NCR710)
+
+/* LASI-specific constants */
+#define LASI_SCSI_RESET         0x000   /* SCSI Reset Register */
+#define LASI_SCSI_NCR710_BASE   0x100   /* NCR53C710 registers start here */
+
+/* PA-RISC device identification register offsets */
+#define PARISC_DEVICE_ID_OFF    0x00    /* HW type, HVERSION, SVERSION */
+#define PARISC_DEVICE_CONFIG_OFF 0x04   /* Configuration data */
+
+/* NCR710 register constants needed by LASI wrapper */
+#define PHASE_MASK              7       /* Mask for phase bits */
+#define PHASE_DO                0       /* Data out phase */
+
+/* NCR710 register bit definitions needed by LASI wrapper */
+#define NCR710_SCNTL1_RST       0x08    /* SCSI Reset */
+#define NCR710_ISTAT_RST        0x40    /* Device Reset */
+#define NCR710_ISTAT_ABRT       0x80    /* Script Abort */
+#define NCR710_ISTAT_CON        0x08    /* Connected */
+#define NCR710_DSTAT_DFE        0x80    /* DMA FIFO Empty */
+#define NCR710_CTEST2_DACK      0x01    /* DMA Acknowledge */
+
+/* LASI NCR53C710 state */
+typedef struct LasiNCR710State {
+    SysBusDevice parent_obj;
+    MemoryRegion mmio;
+    qemu_irq lasi_irq;       /* IRQ line to LASI controller */
+    uint32_t hw_type;        /* Hardware type (HPHW_*) */
+    uint32_t sversion;       /* Software version */
+    uint32_t hversion;       /* Hardware version */
+    SCSIBus bus;
+    NCR710State ncr710;
+} LasiNCR710State;
+
+/* Create and initialize a LASI NCR710 device */
+DeviceState *lasi_ncr710_init(MemoryRegion *addr_space, hwaddr hpa, qemu_irq irq);
+void lasi_ncr710_handle_legacy_cmdline(DeviceState *lasi_dev);
+
+#endif
diff --git a/hw/scsi/ncr53c710.c b/hw/scsi/ncr53c710.c
new file mode 100644
index 0000000000..1384cc3057
--- /dev/null
+++ b/hw/scsi/ncr53c710.c
@@ -0,0 +1,2477 @@
+/*
+ * LASI NCR710 SCSI I/O Processor
+ *
+ * Copyright (c) 2025 Soumyajyotii Ssarkar <soumyajyotisarkar23@gmail.com>
+ * This driver was developed during the Google Summer of Code 2025 program.
+ *
+ * NCR710 SCSI I/O Processor implementation
+ * Based on the NCR53C710 Technical Manual Version 3.2, December 2000
+ *
+ * Developed from an implementation of NCR53C710 by Helge Deller
+ * which was interim based on the implementation by Toni Wilen for UAE.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * Contents:
+ * 1. Register Definitions
+ * 2. Register name functions
+ * 3. Parity functions
+ * 4. SCSI FIFO Structures
+ * 5. Scripts Misc functions
+ * 6. DMA functions
+ * 7. Scripts functions
+ * 8. Read and Write functions
+ * 9. QEMU Device model functions
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/timer.h"
+#include "hw/irq.h"
+#include "hw/sysbus.h"
+#include "hw/scsi/scsi.h"
+#include "hw/scsi/ncr53c710.h"
+#include "migration/vmstate.h"
+#include "system/dma.h"
+#include "qemu/log.h"
+#include "qemu/module.h"
+#include "trace.h"
+#include "qom/object.h"
+
+#define NCR710_MAX_DEVS 7
+
+/* SCNTL0 (0x00) - SCSI Control Register 0 */
+#define NCR710_SCNTL0_TRG    0x01
+#define NCR710_SCNTL0_AAP    0x02
+#define NCR710_SCNTL0_EPG    0x04
+#define NCR710_SCNTL0_EPC    0x08
+#define NCR710_SCNTL0_WATN   0x10
+#define NCR710_SCNTL0_START  0x20
+#define NCR710_SCNTL0_ARB0   0x40
+#define NCR710_SCNTL0_ARB1   0x80
+
+/* SCNTL1 (0x01) - SCSI Control Register 1 */
+#define NCR710_SCNTL1_RES0   0x01
+#define NCR710_SCNTL1_RES1   0x02
+#define NCR710_SCNTL1_AESP   0x04
+#define NCR710_SCNTL1_RST    0x08
+#define NCR710_SCNTL1_CON    0x10
+#define NCR710_SCNTL1_ESR    0x20
+#define NCR710_SCNTL1_ADB    0x40
+#define NCR710_SCNTL1_EXC    0x80
+
+/* ISTAT (0x21) - Interrupt Status Register */
+#define NCR710_ISTAT_DIP    0x01
+#define NCR710_ISTAT_SIP    0x02
+#define NCR710_ISTAT_CON    0x08
+#define NCR710_ISTAT_SIGP   0x20
+#define NCR710_ISTAT_RST    0x40
+#define NCR710_ISTAT_ABRT   0x80
+
+/* SSTAT0 (0x0D) - SCSI Status Register 0 */
+#define NCR710_SSTAT0_PAR    0x01
+#define NCR710_SSTAT0_RST    0x02
+#define NCR710_SSTAT0_UDC    0x04
+#define NCR710_SSTAT0_SGE    0x08
+#define NCR710_SSTAT0_SEL    0x10
+#define NCR710_SSTAT0_STO    0x20
+#define NCR710_SSTAT0_FCMP   0x40
+#define NCR710_SSTAT0_MA     0x80
+
+/* SSTAT1 (0x0E) - SCSI Status Register 1 */
+#define NCR710_SSTAT1_ORF    0x02
+#define NCR710_SSTAT1_ILF    0x04
+
+/* SSTAT2 (0x0F) - SCSI Status Register 2 */
+#define NCR710_SSTAT2_FF0    0x01
+#define NCR710_SSTAT2_FF1    0x02
+#define NCR710_SSTAT2_FF2    0x04
+#define NCR710_SSTAT2_FF3    0x08
+
+/* SOCL (0x07) / SBCL (0x0B) - SCSI Output/Bus Control Lines */
+#define NCR710_SOCL_IO       0x01
+#define NCR710_SOCL_CD       0x02
+#define NCR710_SOCL_MSG      0x04
+#define NCR710_SOCL_ATN      0x08
+#define NCR710_SOCL_SEL      0x10
+#define NCR710_SOCL_BSY      0x20
+#define NCR710_SOCL_ACK      0x40
+#define NCR710_SOCL_REQ      0x80
+
+/* SBCL bits same as SOCL */
+#define NCR710_SBCL_IO       0x01
+#define NCR710_SBCL_CD       0x02
+#define NCR710_SBCL_MSG      0x04
+#define NCR710_SBCL_ATN      0x08
+#define NCR710_SBCL_SEL      0x10
+#define NCR710_SBCL_BSY      0x20
+#define NCR710_SBCL_ACK      0x40
+#define NCR710_SBCL_REQ      0x80
+
+/* DSTAT (0x0C) - DMA Status Register */
+#define NCR710_DSTAT_IID     0x01
+#define NCR710_DSTAT_SIR     0x04
+#define NCR710_DSTAT_SSI     0x08
+#define NCR710_DSTAT_ABRT    0x10
+#define NCR710_DSTAT_BF      0x20
+#define NCR710_DSTAT_MDPE    0x40
+#define NCR710_DSTAT_DFE     0x80
+
+/* DCNTL (0x3B) - DMA Control Register */
+#define NCR710_DCNTL_COM     0x01
+#define NCR710_DCNTL_IRQD    0x02
+#define NCR710_DCNTL_STD     0x04
+#define NCR710_DCNTL_IRQM    0x08
+#define NCR710_DCNTL_SSM     0x10
+#define NCR710_DCNTL_PFEN    0x20
+#define NCR710_DCNTL_PFF     0x40
+
+/* DMODE (0x38) - DMA Mode Register */
+#define NCR710_DMODE_MAN     0x01
+#define NCR710_DMODE_BOF     0x02
+#define NCR710_DMODE_ERMP    0x04
+#define NCR710_DMODE_ERL     0x08
+#define NCR710_DMODE_DIOM    0x10
+#define NCR710_DMODE_SIOM    0x20
+#define NCR710_DMODE_BL_MASK 0xC0
+#define NCR710_DMODE_BL_1    0x00
+#define NCR710_DMODE_BL_2    0x40
+#define NCR710_DMODE_BL_4    0x80
+#define NCR710_DMODE_BL_8    0xC0
+
+/* CTEST2 (0x16) - Chip Test Register 2 */
+#define NCR710_CTEST2_DACK   0x01
+#define NCR710_CTEST2_DREQ   0x02
+#define NCR710_CTEST2_TEOP   0x04
+#define NCR710_CTEST2_PCICIE 0x08
+#define NCR710_CTEST2_CM     0x10
+#define NCR710_CTEST2_CIO    0x20
+#define NCR710_CTEST2_SIGP   0x40
+#define NCR710_CTEST2_DDIR   0x80
+
+/* CTEST5 (0x19) - Chip Test Register 5 */
+#define NCR710_CTEST5_BL2    0x04
+#define NCR710_CTEST5_DDIR   0x08
+#define NCR710_CTEST5_MASR   0x10
+#define NCR710_CTEST5_DFSN   0x20
+#define NCR710_CTEST5_BBCK   0x40
+#define NCR710_CTEST5_ADCK   0x80
+
+/* SCID (0x04) - SCSI Chip ID Register */
+#define NCR710_SCID_RRE      0x60
+#define NCR710_SCID_ID_MASK  0x07
+
+#define NCR710_HOST_ID       7
+
+/* NCR53C710 has 8-byte SCSI FIFO */
+#define NCR710_MAX_MSGIN_LEN 8
+#define NCR710_BUF_SIZE         4096
+
+/* Standard SCSI Message Byte Constants */
+#define SCSI_MSG_ABORT                  0x06
+#define SCSI_MSG_BUS_DEVICE_RESET       0x0c
+#define SCSI_MSG_COMMAND_COMPLETE       0x00
+#define SCSI_MSG_DISCONNECT             0x04
+#define SCSI_MSG_EXTENDED_MESSAGE       0x01
+#define SCSI_MSG_IDENTIFY               0x80
+#define SCSI_MSG_IGNORE_WIDE_RESIDUE    0x23
+#define SCSI_MSG_MESSAGE_PARITY_ERROR   0x09
+#define SCSI_MSG_MESSAGE_REJECT         0x07
+#define SCSI_MSG_NO_OPERATION           0x08
+#define SCSI_MSG_RELEASE_RECOVERY       0x10
+#define SCSI_MSG_RESTORE_POINTERS       0x03
+#define SCSI_MSG_SAVE_DATA_POINTER      0x02
+#define SCSI_MSG_SYNCHRONOUS_DATA_TRANSFER  0x01
+#define SCSI_MSG_WIDE_DATA_TRANSFER     0x03
+
+/* Script interrupt codes */
+#define A_GOOD_STATUS_AFTER_STATUS          0x401
+#define A_DISCONNECT_AFTER_CMD              0x380
+#define A_DISCONNECT_AFTER_DATA             0x580
+#define A_DISCONNECT_DURING_DATA            0x780
+#define A_RESELECTION_IDENTIFIED            0x1003
+#define A_UNEXPECTED_PHASE                  0x20
+#define A_FATAL                             0x2000
+#define A_DEBUG_INTERRUPT                   0x3000
+
+/* SCSI Script execution states */
+#define SCRIPT_STATE_IDLE                  0
+#define SCRIPT_STATE_SELECTING             1
+#define SCRIPT_STATE_COMMAND               2
+#define SCRIPT_STATE_DATA                  3
+#define SCRIPT_STATE_STATUS                4
+#define SCRIPT_STATE_MESSAGE               5
+#define SCRIPT_STATE_DISCONNECTED          6
+
+#define AFTER_SELECTION 	0x100
+#define BEFORE_CMD 		    0x200
+#define AFTER_CMD 		    0x300
+#define AFTER_STATUS 		0x400
+#define AFTER_DATA_IN		0x500
+#define AFTER_DATA_OUT		0x600
+#define DURING_DATA_IN		0x700
+
+#define NOT_MSG_OUT 		0x10
+#define UNEXPECTED_PHASE 	0x20
+#define NOT_MSG_IN 		    0x30
+#define UNEXPECTED_MSG		0x40
+#define MSG_IN			    0x50
+#define SDTR_MSG_R		    0x60
+#define REJECT_MSG_R		0x70
+#define DISCONNECT		    0x80
+#define MSG_OUT			    0x90
+#define WDTR_MSG_R		    0xA0
+
+#define GOOD_STATUS     0x1
+
+#define NOT_MSG_OUT_AFTER_SELECTION         0x110
+#define UNEXPECTED_PHASE_BEFORE_CMD         0x220
+#define UNEXPECTED_PHASE_AFTER_CMD          0x320
+#define NOT_MSG_IN_AFTER_STATUS             0x430
+#define GOOD_STATUS_AFTER_STATUS            0x401
+#define UNEXPECTED_PHASE_AFTER_DATA_IN      0x520
+#define UNEXPECTED_PHASE_AFTER_DATA_OUT     0x620
+#define UNEXPECTED_MSG_BEFORE_CMD           0x240
+#define MSG_IN_BEFORE_CMD                   0x250
+#define MSG_IN_AFTER_CMD                    0x350
+#define SDTR_MSG_BEFORE_CMD                 0x260
+#define REJECT_MSG_BEFORE_CMD               0x270
+#define DISCONNECT_AFTER_CMD                0x380
+#define SDTR_MSG_AFTER_CMD                  0x360
+#define WDTR_MSG_AFTER_CMD                  0x3A0
+#define MSG_IN_AFTER_STATUS                 0x440
+#define DISCONNECT_AFTER_DATA               0x580
+#define MSG_IN_AFTER_DATA_IN                0x550
+#define MSG_IN_AFTER_DATA_OUT               0x650
+#define MSG_OUT_AFTER_DATA_IN               0x590
+#define DATA_IN_AFTER_DATA_IN               0x5a0
+#define MSG_IN_DURING_DATA_IN               0x750
+#define DISCONNECT_DURING_DATA              0x780
+
+#define RESELECTED_DURING_SELECTION      0x1000
+#define COMPLETED_SELECTION_AS_TARGET    0x1001
+#define RESELECTION_IDENTIFIED           0x1003
+
+#define FATAL                   0x2000
+#define FATAL_UNEXPECTED_RESELECTION_MSG 0x2000
+#define FATAL_SEND_MSG          0x2001
+#define FATAL_NOT_MSG_IN_AFTER_SELECTION 0x2002
+#define FATAL_ILLEGAL_MSG_LENGTH 0x2003
+
+#define DEBUG_INTERRUPT     0x3000
+#define DEBUG_INTERRUPT1    0x3001
+#define DEBUG_INTERRUPT2    0x3002
+#define DEBUG_INTERRUPT3    0x3003
+#define DEBUG_INTERRUPT4    0x3004
+#define DEBUG_INTERRUPT5    0x3005
+#define DEBUG_INTERRUPT6    0x3006
+
+#define COMMAND_COMPLETE_MSG    0x00
+#define EXTENDED_MSG		    0x01
+#define SDTR_MSG		        0x01
+#define SAVE_DATA_PTRS_MSG	    0x02
+#define RESTORE_DATA_PTRS_MSG	0x03
+#define WDTR_MSG		        0x03
+#define DISCONNECT_MSG		    0x04
+#define REJECT_MSG		        0x07
+#define PARITY_ERROR_MSG	    0x09
+#define SIMPLE_TAG_MSG		    0x20
+#define IDENTIFY_MSG		    0x80
+#define IDENTIFY_MSG_MASK	    0x7F
+#define TWO_BYTE_MSG		    0x20
+#define TWO_BYTE_MSG_MASK	    0x0F
+
+
+
+/* SCSI phases */
+#define PHASE_DO   0  /* Data out phase */
+#define PHASE_DI   1  /* Data in phase */
+#define PHASE_CO   2  /* Command phase */
+#define PHASE_SI   3  /* Status phase */
+#define PHASE_ST   3  /* Status phase (alias) */
+#define PHASE_MO   6  /* Message out phase */
+#define PHASE_MI   7  /* Message in phase */
+#define PHASE_MASK 7  /* Mask for phase bits */
+
+
+#define NCR710_TAG_VALID     (1 << 16)
+
+static void ncr710_scsi_fifo_init(NCR710_SCSI_FIFO *fifo);
+const char *ncr710_reg_name(int offset);
+static void ncr710_script_scsi_interrupt(NCR710State *s, int stat0);
+static void ncr710_update_irq(NCR710State *s);
+static void ncr710_script_dma_interrupt(NCR710State *s, int stat);
+static void ncr710_request_free(NCR710State *s, NCR710Request *p);
+static inline void ncr710_dma_read(NCR710State *s, uint32_t addr, void *buf, uint32_t len);
+static inline void ncr710_dma_write(NCR710State *s, uint32_t addr, const void *buf, uint32_t len);
+
+static inline int ncr710_irq_on_rsl(NCR710State *s)
+{
+    return (s->sien0 & NCR710_SSTAT0_SEL) != 0;
+}
+
+static void ncr710_clear_pending_irq(NCR710State *s)
+{
+    if (s->current) {
+        if (s->current->req) {
+            s->current->req->hba_private = NULL;
+        }
+        ncr710_request_free(s, s->current);
+        s->current = NULL;
+    }
+}
+
+void ncr710_soft_reset(NCR710State *s)
+{
+    s->carry = 0;
+    s->msg_action = NCR710_MSG_ACTION_NONE;
+    s->msg_len = 0;
+    s->waiting = NCR710_WAIT_NONE;
+    s->wait_reselect = false;
+    s->reselection_id = 0;
+    s->dsa = 0;
+    s->dnad = 0;
+    s->dbc = 0;
+    s->temp = 0;
+	s->scratch = 0;
+    s->istat &= 0x40;
+    s->dcmd = 0x40;
+    s->dstat = NCR710_DSTAT_DFE;
+    s->dien = 0x04;
+    s->sien0 = 0;
+    s->ctest2 = NCR710_CTEST2_DACK;
+    s->ctest3 = 0;
+    s->ctest4 = 0;
+    s->ctest5 = 0;
+    s->dsp = 0;
+    s->dsps = 0;
+    s->dmode = 0;
+    s->dcntl = 0;
+    s->scntl0 = 0xc0;
+    s->scntl1 = 0;
+    s->sstat0 = 0;
+    s->sstat1 = 0;
+	s->sstat2 = 0;
+    s->scid = 0x80;
+    s->sxfer = 0;
+    s->socl = 0;
+    s->sdid = 0;
+    s->sbcl = 0;
+    s->sidl = 0;
+    s->sfbr = 0;
+    qemu_set_irq(s->irq, 0);
+    ncr710_clear_pending_irq(s);
+    ncr710_scsi_fifo_init(&s->scsi_fifo);
+}
+
+const char *ncr710_reg_name(int offset)
+{
+    switch (offset) {
+    case NCR710_SCNTL0_REG:  return "SCNTL0";
+    case NCR710_SCNTL1_REG:  return "SCNTL1";
+    case NCR710_SDID_REG:    return "SDID";
+    case NCR710_SIEN_REG:    return "SIEN";
+    case NCR710_SCID_REG:    return "SCID";
+    case NCR710_SXFER_REG:   return "SXFER";
+    case NCR710_SODL_REG:    return "SODL";
+    case NCR710_SOCL_REG:    return "SOCL";
+    case NCR710_SFBR_REG:    return "SFBR";
+    case NCR710_SIDL_REG:    return "SIDL";
+    case NCR710_SBDL_REG:    return "SBDL";
+    case NCR710_SBCL_REG:    return "SBCL";
+    case NCR710_DSTAT_REG:   return "DSTAT";
+    case NCR710_SSTAT0_REG:  return "SSTAT0";
+    case NCR710_SSTAT1_REG:  return "SSTAT1";
+    case NCR710_SSTAT2_REG:  return "SSTAT2";
+    case NCR710_DSA_REG:     return "DSA";
+    case NCR710_DSA_REG+1:   return "DSA+1";
+    case NCR710_DSA_REG+2:   return "DSA+2";
+    case NCR710_DSA_REG+3:   return "DSA+3";
+    case NCR710_CTEST0_REG:  return "CTEST0";
+    case NCR710_CTEST1_REG:  return "CTEST1";
+    case NCR710_CTEST2_REG:  return "CTEST2";
+    case NCR710_CTEST3_REG:  return "CTEST3";
+    case NCR710_CTEST4_REG:  return "CTEST4";
+    case NCR710_CTEST5_REG:  return "CTEST5";
+    case NCR710_CTEST6_REG:  return "CTEST6";
+    case NCR710_CTEST7_REG:  return "CTEST7";
+    case NCR710_TEMP_REG:    return "TEMP";
+    case NCR710_TEMP_REG+1:  return "TEMP+1";
+    case NCR710_TEMP_REG+2:  return "TEMP+2";
+    case NCR710_TEMP_REG+3:  return "TEMP+3";
+    case NCR710_DFIFO_REG:   return "DFIFO";
+    case NCR710_ISTAT_REG:   return "ISTAT";
+    case NCR710_CTEST8_REG:  return "CTEST8";
+    case NCR710_LCRC_REG:    return "LCRC";
+    case NCR710_DBC_REG:     return "DBC";
+    case NCR710_DBC_REG+1:   return "DBC+1";
+    case NCR710_DBC_REG+2:   return "DBC+2";
+    case NCR710_DCMD_REG:    return "DCMD";
+    case NCR710_DNAD_REG:    return "DNAD";
+    case NCR710_DNAD_REG+1:  return "DNAD+1";
+    case NCR710_DNAD_REG+2:  return "DNAD+2";
+    case NCR710_DNAD_REG+3:  return "DNAD+3";
+    case NCR710_DSP_REG:     return "DSP";
+    case NCR710_DSP_REG+1:   return "DSP+1";
+    case NCR710_DSP_REG+2:   return "DSP+2";
+    case NCR710_DSP_REG+3:   return "DSP+3";
+    case NCR710_DSPS_REG:    return "DSPS";
+    case NCR710_DSPS_REG+1:  return "DSPS+1";
+    case NCR710_DSPS_REG+2:  return "DSPS+2";
+    case NCR710_DSPS_REG+3:  return "DSPS+3";
+    case NCR710_SCRATCH_REG: return "SCRATCH";
+    case NCR710_SCRATCH_REG+1: return "SCRATCH+1";
+    case NCR710_SCRATCH_REG+2: return "SCRATCH+2";
+    case NCR710_SCRATCH_REG+3: return "SCRATCH+3";
+    case NCR710_DMODE_REG:   return "DMODE";
+    case NCR710_DIEN_REG:    return "DIEN";
+    case NCR710_DWT_REG:     return "DWT";
+    case NCR710_DCNTL_REG:   return "DCNTL";
+    case NCR710_ADDER_REG:   return "ADDER";
+    case NCR710_ADDER_REG+1: return "ADDER+1";
+    case NCR710_ADDER_REG+2: return "ADDER+2";
+    case NCR710_ADDER_REG+3: return "ADDER+3";
+    default:                 return "UNKNOWN";
+    }
+}
+
+/*
+ * Parity is not insightful in the emulation env.
+ * however we keep a basic form of parity just for consistency
+ */
+static uint8_t ncr710_generate_scsi_parity(NCR710State *s, uint8_t data)
+{
+    uint8_t parity = parity8(data);
+
+    if (s->scntl1 & NCR710_SCNTL1_AESP) {
+        parity = !parity;
+    }
+
+    return parity;
+}
+
+static bool ncr710_check_scsi_parity(NCR710State *s, uint8_t data, uint8_t parity)
+{
+    if (!(s->scntl0 & NCR710_SCNTL0_EPC)) {
+        return true;
+    }
+
+    uint8_t expected_parity = ncr710_generate_scsi_parity(s, data);
+    return parity == expected_parity;
+}
+
+static void ncr710_handle_parity_error(NCR710State *s)
+{
+    s->sstat0 |= NCR710_SSTAT0_PAR;
+
+    if (s->scntl0 & NCR710_SCNTL0_AAP) {
+        s->socl |= NCR710_SOCL_ATN;
+    }
+
+    ncr710_script_scsi_interrupt(s, NCR710_SSTAT0_PAR);
+}
+
+/*
+ * NCR710 SCSI FIFO IMPLEMENTATION
+ *
+ * NCR710 SCSI FIFO Specifications:
+ * - Width: 9 bits (8 data bits + 1 parity bit per byte lane)
+ * - Data Width: 1 byte (8 bits) per transfer
+ * - Depth: 8 transfers deep
+ * - Total Capacity: 8-byte FIFO
+ *
+ * SCSI FIFO Data Flow:
+ * - Enqueue: Add byte at tail position (head + count)
+ * - Dequeue: Remove byte from head position
+ * - Status: Empty when count=0, Full when count=8
+ */
+
+/* SCSI FIFO Operations:
+ * - ncr710_scsi_fifo_init() - Initialize 8-deep FIFO
+ * - ncr710_scsi_fifo_enqueue() - Add byte to FIFO tail
+ * - ncr710_scsi_fifo_dequeue() - Remove byte from FIFO head
+ * - ncr710_scsi_fifo_empty/full() - Check FIFO status
+ *
+ * Our FIFO Implementation is a bit flimsy but works for now.
+ * TODO: Improve FIFO implementation.
+ */
+
+static void ncr710_scsi_fifo_init(NCR710_SCSI_FIFO *fifo)
+{
+    memset(fifo->data, 0, NCR710_SCSI_FIFO_SIZE);
+    memset(fifo->parity, 0, NCR710_SCSI_FIFO_SIZE);
+    fifo->head = 0;
+    fifo->count = 0;
+}
+
+static inline bool ncr710_scsi_fifo_empty(NCR710_SCSI_FIFO *fifo)
+{
+    return fifo->count == 0;
+}
+
+static inline bool ncr710_scsi_fifo_full(NCR710_SCSI_FIFO *fifo)
+{
+    return fifo->count == NCR710_SCSI_FIFO_SIZE;
+}
+
+static inline int ncr710_scsi_fifo_enqueue(NCR710_SCSI_FIFO *fifo, uint8_t data, uint8_t parity)
+{
+    if (ncr710_scsi_fifo_full(fifo)) {
+        return -1; /* FIFO full - 8 transfers deep */
+    }
+
+    /* Add data at the tail position (head + count) */
+    int tail_pos = (fifo->head + fifo->count) % NCR710_SCSI_FIFO_SIZE;
+    fifo->data[tail_pos] = data;
+    fifo->parity[tail_pos] = parity;
+    fifo->count++;
+
+    return 0;
+}
+
+static inline uint8_t ncr710_scsi_fifo_dequeue(NCR710_SCSI_FIFO *fifo, uint8_t *parity)
+{
+    uint8_t data;
+
+    if (ncr710_scsi_fifo_empty(fifo)) {
+        *parity = 0;
+        return 0;
+    }
+
+    /* Take data from the head position */
+    data = fifo->data[fifo->head];
+    *parity = fifo->parity[fifo->head];
+    fifo->head = (fifo->head + 1) % NCR710_SCSI_FIFO_SIZE;
+    fifo->count--;
+
+    return data;
+}
+
+static uint8_t ncr710_reg_readb(NCR710State *s, int offset);
+static void ncr710_reg_writeb(NCR710State *s, int offset, uint8_t val);
+
+static inline uint32_t ncr710_read_dword(NCR710State *s, uint32_t addr)
+{
+    uint32_t buf;
+    address_space_read(&address_space_memory, addr, MEMTXATTRS_UNSPECIFIED,
+                      (uint8_t *)&buf, 4);
+    /* The NCR710 datasheet saying "operates internally in LE mode"
+     * refers to its internal register organization,
+     * not how it reads SCRIPTS from host memory.
+     * This was initially confusing.
+    */
+    buf = be32_to_cpu(buf);
+    NCR710_DPRINTF("Read dword %08x from %08x\n", buf, addr);
+    return buf;
+}
+
+static inline void ncr710_dma_read(NCR710State *s, uint32_t addr, void *buf, uint32_t len)
+{
+    address_space_read(&address_space_memory, addr, MEMTXATTRS_UNSPECIFIED,
+        buf, len);
+    NCR710_DPRINTF("Read %d bytes from %08x: ", len, addr);
+    for (int i = 0; i < len && i < 16; i++) {
+         NCR710_DPRINTF("%02x ", ((uint8_t*)buf)[i]);
+    }
+     NCR710_DPRINTF("\n");
+}
+
+static inline void ncr710_dma_write(NCR710State *s, uint32_t addr, const void *buf, uint32_t len)
+{
+    address_space_write(&address_space_memory, addr, MEMTXATTRS_UNSPECIFIED,
+                       buf, len);
+    NCR710_DPRINTF("Wrote %d bytes to %08x\n", len, addr);
+}
+
+static void ncr710_stop_script(NCR710State *s)
+{
+    s->script_active = 0;
+    s->scntl1 &= ~NCR710_SCNTL1_CON;
+    s->istat &= ~NCR710_ISTAT_CON;
+}
+
+static void ncr710_update_irq(NCR710State *s)
+{
+    int level = 0;
+
+    if (s->dstat) {
+        if (s->dstat & s->dien) {
+            level = 1;
+        }
+        s->istat |= NCR710_ISTAT_DIP;
+    } else {
+        s->istat &= ~NCR710_ISTAT_DIP;
+    }
+
+    if (s->sstat0) {
+        if ((s->sstat0 & s->sien0)) {
+            level = 1;
+        }
+        s->istat |= NCR710_ISTAT_SIP;
+    } else {
+        s->istat &= ~NCR710_ISTAT_SIP;
+    }
+
+    qemu_set_irq(s->irq, level);
+}
+
+static void ncr710_script_scsi_interrupt(NCR710State *s, int stat0)
+{
+    uint32_t mask0;
+
+    trace_ncr710_script_scsi_interrupt(stat0, s->sstat0);
+    s->sstat0 |= stat0;
+    mask0 = stat0 & s->sien0;
+    if (mask0) {
+        ncr710_stop_script(s);
+        s->istat |= NCR710_ISTAT_SIP;
+        ncr710_update_irq(s);
+    }
+}
+
+void ncr710_completion_irq_callback(void *opaque)
+{
+    NCR710State *s = (NCR710State *)opaque;
+
+    s->dsps = s->saved_dsps;
+    if (s->dstat & NCR710_DSTAT_DFE) {
+        s->dstat &= ~NCR710_DSTAT_DFE;
+    }
+    s->dstat |= NCR710_DSTAT_SIR;
+    ncr710_update_irq(s);
+    ncr710_stop_script(s);
+}
+
+static void ncr710_script_dma_interrupt(NCR710State *s, int stat)
+{
+    trace_ncr710_script_dma_interrupt(stat, s->dstat);
+    if (stat == NCR710_DSTAT_SIR && (s->dstat & NCR710_DSTAT_DFE)) {
+        s->dstat &= ~NCR710_DSTAT_DFE;
+    }
+
+    s->dstat |= stat;
+    s->istat |= NCR710_ISTAT_DIP;
+    ncr710_update_irq(s);
+    ncr710_stop_script(s);
+}
+
+inline void ncr710_set_phase(NCR710State *s, int phase)
+{
+    s->sstat2 = (s->sstat2 & ~PHASE_MASK) | phase;
+	s->ctest0 &= ~1;
+	if (phase == PHASE_DI)
+		s->ctest0 |= 1;
+	s->sbcl &= ~NCR710_SBCL_REQ;
+}
+
+static void ncr710_disconnect(NCR710State *s)
+{
+    trace_ncr710_disconnect(s->waiting);
+    if (s->waiting == NCR710_WAIT_NONE) {
+        s->scntl1 &= ~NCR710_SCNTL1_CON;
+        s->istat &= ~NCR710_ISTAT_CON;
+    }
+    s->sstat2 &= ~PHASE_MASK;
+}
+
+static void ncr710_bad_selection(NCR710State *s, uint32_t id)
+{
+    trace_ncr710_bad_selection(id);
+    s->dstat = 0;
+    s->dsps = 0;
+    ncr710_script_scsi_interrupt(s, NCR710_SSTAT0_STO);
+    ncr710_disconnect(s);
+}
+
+static void ncr710_clear_selection_timeout(NCR710State *s)
+{
+    if (s->sstat0 & NCR710_SSTAT0_STO) {
+        s->sstat0 &= ~NCR710_SSTAT0_STO;
+        ncr710_clear_pending_irq(s);
+        if (s->sstat0 == 0) {
+            s->istat &= ~NCR710_ISTAT_SIP;
+        }
+        ncr710_update_irq(s);
+    }
+}
+
+/* Initiate a SCSI layer data transfer using FIFOs.  */
+static void ncr710_do_dma(NCR710State *s, int out)
+{
+    uint32_t count;
+    uint32_t addr;
+    SCSIDevice *dev;
+    assert(s->current);
+    if (!s->current->dma_len) {
+        /* Wait until data is available.  */
+        return;
+    }
+
+    dev = s->current->req->dev;
+    assert(dev);
+
+    count = s->dbc;
+    if (count > s->current->dma_len)
+        count = s->current->dma_len;
+
+    addr = s->dnad;
+
+    s->dnad += count;
+    s->dbc -= count;
+     if (s->current->dma_buf == NULL) {
+		 s->current->dma_buf = scsi_req_get_buf(s->current->req);
+    }
+    /* ??? Set SFBR to first data byte.  */
+    if (out) {
+		ncr710_dma_read(s, addr, s->current->dma_buf, count);
+    } else {
+		ncr710_dma_write(s, addr, s->current->dma_buf, count);
+    }
+    s->current->dma_len -= count;
+    if (s->current->dma_len == 0) {
+        s->current->dma_buf = NULL;
+        s->current->pending = 0;  /* Clear pending flag when transfer completes */
+        scsi_req_continue(s->current->req);
+    } else {
+        s->current->dma_buf += count;
+        s->waiting = NCR710_WAIT_NONE;
+        ncr710_execute_script(s);
+    }
+}
+
+static void ncr710_add_msg_byte(NCR710State *s, uint8_t data)
+{
+    if (s->msg_len >= NCR710_MAX_MSGIN_LEN) {
+        BADF("MSG IN data too long\n");
+    } else {
+        s->msg[s->msg_len++] = data;
+    }
+}
+
+static void ncr710_request_free(NCR710State *s, NCR710Request *p)
+{
+    if (p == s->current) {
+        s->current = NULL;
+    }
+    g_free(p);
+}
+
+void ncr710_request_cancelled(SCSIRequest *req)
+{
+    NCR710State *s = ncr710_from_scsi_bus(req->bus);
+    NCR710Request *p = (NCR710Request*)req->hba_private;
+    req->hba_private = NULL;
+    ncr710_request_free(s, p);
+	scsi_req_unref(req);
+}
+
+static int ncr710_queue_req(NCR710State *s, SCSIRequest *req, uint32_t len)
+{
+    NCR710Request *p = (NCR710Request*)req->hba_private;
+
+    if (p->pending) {
+        BADF("Multiple IO pending for request %p\n", p);
+    }
+    p->pending = len;
+    if ((s->waiting == NCR710_WAIT_RESELECT && !(s->istat & (NCR710_ISTAT_SIP | NCR710_ISTAT_DIP))) ||
+        (ncr710_irq_on_rsl(s) && !(s->scntl1 & NCR710_SCNTL1_CON) &&
+         !(s->istat & (NCR710_ISTAT_SIP | NCR710_ISTAT_DIP)))) {
+        s->current = p;
+        return 0;
+    } else {
+        p->pending = len;
+        s->current = p;
+        return 1;
+    }
+}
+
+ /* Callback to indicate that the SCSI layer has completed a command.  */
+void ncr710_command_complete(SCSIRequest *req, size_t resid)
+{
+    NCR710State *s = ncr710_from_scsi_bus(req->bus);
+    NCR710Request *p = (NCR710Request*)req->hba_private;
+
+    trace_ncr710_command_complete(req->tag, req->status);
+
+    s->lcrc = 0;
+    s->status = req->status;
+    s->command_complete = NCR710_CMD_COMPLETE;
+
+    if (p) {
+        p->pending = 0;
+    }
+
+    ncr710_set_phase(s, PHASE_ST);
+
+    if (req->hba_private == s->current) {
+        scsi_req_unref(req);
+    }
+
+    if (s->waiting == NCR710_WAIT_RESELECT) {
+        s->waiting = NCR710_WAIT_NONE;
+        ncr710_execute_script(s);
+    } else if (s->waiting == NCR710_WAIT_DMA) {
+        s->waiting = NCR710_WAIT_NONE;
+        ncr710_execute_script(s);
+    }
+}
+
+ /* Callback to indicate that the SCSI layer has completed a transfer.  */
+void ncr710_transfer_data(SCSIRequest *req, uint32_t len)
+{
+    NCR710State *s = ncr710_from_scsi_bus(req->bus);
+
+    assert(req->hba_private);
+
+    if (s->waiting == NCR710_WAIT_DMA) {
+
+        /* Update current request with data length */
+        NCR710Request *p = (NCR710Request *)req->hba_private;
+        if (p) {
+            p->dma_len = len;
+        }
+        s->dsp -= 8;  /* Back up to the DO_DMA instruction (8 bytes: opcode + address) */
+
+        s->waiting = NCR710_WAIT_NONE;
+
+        ncr710_execute_script(s);
+        return;
+    }
+
+    if (s->wait_reselect) {
+
+        s->current = (NCR710Request *)req->hba_private;
+        s->current->dma_len = len;
+
+        s->waiting = NCR710_WAIT_RESELECT;  /* Mark as reselection in progress */
+    }
+
+    if (req->hba_private != s->current ||
+        (ncr710_irq_on_rsl(s) && !(s->scntl1 & NCR710_SCNTL1_CON))|| s->waiting == NCR710_WAIT_RESELECT) {
+        if (ncr710_queue_req(s, req, len) != 0) {
+            return;
+        }
+    }
+
+    /* host adapter (re)connected */
+    s->current->dma_len = len;
+    s->command_complete = NCR710_CMD_DATA_READY;
+    if (!s->current) {
+        return;
+    }
+    if (s->waiting) {
+        s->scntl1 |= NCR710_SCNTL1_CON;
+        s->istat |= NCR710_ISTAT_CON;
+        s->sbcl = NCR710_SBCL_IO | NCR710_SBCL_CD | NCR710_SBCL_MSG |
+                  NCR710_SBCL_BSY | NCR710_SBCL_SEL | NCR710_SBCL_REQ;
+        uint8_t host_id = (s->scid & 0x07);  /* Extract host ID from SCID register (bits 2-0) */
+
+        /* Special case: both target and host are ID 0
+         * So, linux expects 0x00 for target 0
+         */
+        if (req->dev->id == 0 && host_id == 0) {
+            s->sfbr = 0x00;
+        } else {
+            /* For non-zero IDs, we use standard bit positions */
+            s->sfbr = (req->dev->id == 0 ? 0 : (1 << req->dev->id)) |
+                      (host_id == 0 ? 0 : (1 << host_id));
+        }
+
+        /* Set phase to MESSAGE IN for GetReselectionData SCRIPTS */
+        ncr710_set_phase(s, PHASE_MI);
+
+        /* Prepare reselection message for GetReselectionData to read:
+         * - Byte 0: IDENTIFY message (0x80 | LUN)
+         * - Bytes 1-2: Tag message if tagged (0x20 = SIMPLE_TAG, then tag number)
+         *
+         * The GetReselectionData SCRIPTS will read 1 byte (for untagged) or
+         * 3 bytes (for tagged) using MOVE instructions in MESSAGE IN phase.
+         */
+        if (s->current) {
+            uint8_t identify_msg = 0x80 | (req->lun & 0x07);  /* IDENTIFY + LUN */
+            ncr710_add_msg_byte(s, identify_msg);
+
+            /* If this is a tagged command, add tag bytes */
+            if (s->current->tag) {
+                ncr710_add_msg_byte(s, 0x20);  /* SIMPLE_TAG_MSG */
+                ncr710_add_msg_byte(s, s->current->tag & 0xff);
+            }
+        }
+
+
+        s->sstat0 |= NCR710_SSTAT0_SEL;  /* Set SELECTED bit */
+        s->istat |= NCR710_ISTAT_SIP;    /* Set SCSI interrupt pending */
+        s->dsps = RESELECTED_DURING_SELECTION;  /* Set DSPS to 0x1000 */
+        ncr710_update_irq(s);
+
+
+        /* Clear waiting flag - reselection now driver's responsibility */
+        s->waiting = NCR710_WAIT_NONE;
+        return;
+    }
+}
+
+static int idbitstonum(uint8_t id)
+{
+	return 7 - clz8(id);
+}
+
+static void ncr710_do_command(NCR710State *s)
+{
+    SCSIDevice *dev;
+    uint8_t buf[16];
+    uint32_t id;
+    int n;
+    int bytes_read;
+    if (s->dbc > 16)
+        s->dbc = 16;
+
+    /* Read command data directly from memory
+     * NOTE: SCSI commands can be up to 16 bytes (e.g., READ_CAPACITY_10 is 10 bytes)
+     * but the NCR710 SCSI FIFO is only 8 bytes deep. For command phase, we bypass
+     * the FIFO and read directly from memory since commands don't need FIFO buffering.
+     */
+    bytes_read = MIN(s->dbc, sizeof(buf));
+    ncr710_dma_read(s, s->dnad, buf, bytes_read);
+
+    s->dnad += bytes_read;
+    s->dbc -= bytes_read;
+    s->sfbr = buf[0];
+
+
+    s->command_complete = NCR710_CMD_PENDING;
+    id = (s->select_tag >> 8) & 0xff;
+    s->lcrc = id;
+
+    dev = scsi_device_find(&s->bus, 0, idbitstonum(id), s->current_lun);
+
+    if (!dev) {
+        ncr710_bad_selection(s, id);
+        return;
+    }
+
+    if (s->current) {
+        ncr710_request_free(s, s->current);
+        s->current = NULL;
+    }
+
+    s->current = g_new0(NCR710Request, 1);
+    s->current->tag = s->select_tag;
+    s->current->resume_offset = 0;
+
+    s->current->req = scsi_req_new(dev, s->current->tag, s->current_lun, buf, bytes_read, s->current);
+    n = scsi_req_enqueue(s->current->req);
+    if (n) {
+        if (n > 0) {
+            ncr710_set_phase(s, PHASE_DI);
+        } else if (n < 0) {
+            ncr710_set_phase(s, PHASE_DO);
+        }
+        scsi_req_continue(s->current->req);
+    }
+    if (!s->command_complete) {
+        if (n) {
+        } else {
+            ncr710_set_phase(s, PHASE_SI);
+        }
+    }
+}
+
+static void ncr710_do_status(NCR710State *s)
+{
+    uint8_t status = s->status;
+    uint8_t parity = 0;
+
+    if (s->dbc != 1)
+        BADF("Bad Status move\n");
+    s->dbc = 1;
+    s->sfbr = status;
+
+    if (s->scntl0 & NCR710_SCNTL0_EPG) {
+        parity = ncr710_generate_scsi_parity(s, status);
+    }
+    ncr710_scsi_fifo_enqueue(&s->scsi_fifo, status, parity);
+
+    status = ncr710_scsi_fifo_dequeue(&s->scsi_fifo, &parity);
+    if (s->scntl0 & NCR710_SCNTL0_EPC) {
+        if (!ncr710_check_scsi_parity(s, status, parity)) {
+            ncr710_handle_parity_error(s);
+        }
+    }
+    ncr710_dma_write(s, s->dnad, &status, 1);
+
+    s->dnad += 1;
+    s->dbc  -= 1;
+
+    ncr710_set_phase(s, PHASE_MI);
+    s->msg_action = NCR710_MSG_ACTION_DISCONNECT;
+    ncr710_add_msg_byte(s, 0); /* COMMAND COMPLETE */
+}
+
+static void ncr710_do_msgin(NCR710State *s)
+{
+    int len;
+    len = s->msg_len;
+    if (len > s->dbc) {
+        len = s->dbc;
+    }
+    s->sfbr = s->msg[0];
+
+    for (int i = 0; i < len; i++) {
+        uint8_t parity = 0;
+        if (s->scntl0 & NCR710_SCNTL0_EPG) {
+            parity = ncr710_generate_scsi_parity(s, s->msg[i]);
+        }
+        ncr710_scsi_fifo_enqueue(&s->scsi_fifo, s->msg[i], parity);
+    }
+
+    uint8_t buf[NCR710_MAX_MSGIN_LEN];
+    for (int i = 0; i < len; i++) {
+        uint8_t parity;
+        buf[i] = ncr710_scsi_fifo_dequeue(&s->scsi_fifo, &parity);
+        if (s->scntl0 & NCR710_SCNTL0_EPC) {
+            if (!ncr710_check_scsi_parity(s, buf[i], parity)) {
+                ncr710_handle_parity_error(s);
+            }
+        }
+    }
+    ncr710_dma_write(s, s->dnad, buf, len);
+
+    s->dnad += len;
+    s->dbc  -= len;
+    s->sidl = s->msg[len - 1];
+    s->msg_len -= len;
+    if (s->msg_len) {
+        memmove(s->msg, s->msg + len, s->msg_len);
+        return;
+    }
+    switch (s->msg_action) {
+    case NCR710_MSG_ACTION_NONE:
+        ncr710_set_phase(s, PHASE_CO);
+        break;
+    case NCR710_MSG_ACTION_DISCONNECT:
+        ncr710_disconnect(s);
+        break;
+    case NCR710_MSG_ACTION_DATA_OUT:
+        ncr710_set_phase(s, PHASE_DO);
+        break;
+    case NCR710_MSG_ACTION_DATA_IN:
+        ncr710_set_phase(s, PHASE_DI);
+        break;
+    default:
+        abort();
+    }
+}
+
+static void ncr710_do_msgout(NCR710State *s)
+{
+    NCR710Request *current_req = s->current;
+
+    while (s->dbc > 0) {
+        int to_move = MIN((int)s->dbc, NCR710_SCSI_FIFO_SIZE);
+        uint8_t temp_buf[NCR710_SCSI_FIFO_SIZE];
+
+        ncr710_dma_read(s, s->dnad, temp_buf, to_move);
+
+        int filled = 0;
+        for (int j = 0; j < to_move && !ncr710_scsi_fifo_full(&s->scsi_fifo); j++) {
+            uint8_t parity = 0;
+            if (s->scntl0 & NCR710_SCNTL0_EPG) {
+                parity = ncr710_generate_scsi_parity(s, temp_buf[j]);
+            }
+            if (ncr710_scsi_fifo_enqueue(&s->scsi_fifo, temp_buf[j], parity) == 0) {
+                filled++;
+            } else {
+                break;
+            }
+        }
+
+        if (filled <= 0) {
+            break;
+        }
+
+        uint8_t buf[NCR710_SCSI_FIFO_SIZE];
+        int bytes = 0;
+        for (int j = 0; j < filled && !ncr710_scsi_fifo_empty(&s->scsi_fifo); j++) {
+            uint8_t parity;
+            buf[bytes] = ncr710_scsi_fifo_dequeue(&s->scsi_fifo, &parity);
+            if (s->scntl0 & NCR710_SCNTL0_EPC) {
+                if (!ncr710_check_scsi_parity(s, buf[bytes], parity)) {
+                    ncr710_handle_parity_error(s);
+                }
+            }
+            bytes++;
+        }
+
+        s->dnad += bytes;
+        s->dbc  -= bytes;
+
+        int i = 0;
+        while (i < bytes) {
+            uint8_t msg = buf[i++];
+            s->sfbr = msg;
+
+            switch (msg) {
+            case SCSI_MSG_COMMAND_COMPLETE:
+                /* 0x00 - NOP / padding byte / Command Complete
+                 * Just ignore padding bytes, continue processing
+                 */
+                break;
+
+            case SCSI_MSG_DISCONNECT: /* 0x04 - Disconnect */
+                ncr710_disconnect(s);
+                break;
+
+            case SCSI_MSG_MESSAGE_REJECT: /* 0x07 - Message Reject */
+                /* Target is rejecting our last message */
+                ncr710_set_phase(s, PHASE_CO);
+                break;
+
+            case SCSI_MSG_NO_OPERATION: /* 0x08 - NOP */
+                ncr710_set_phase(s, PHASE_CO);
+                break;
+
+            case SCSI_MSG_SAVE_DATA_POINTER: /* 0x02 - Save Data Pointer */
+                break;
+
+            case SCSI_MSG_RESTORE_POINTERS: /* 0x03 - Restore Pointers */
+                break;
+
+            case SCSI_MSG_EXTENDED_MESSAGE: { /* 0x01 - Extended message */
+                if (i >= bytes) {
+                    i--;
+                    goto out_chunk;
+                }
+#if ENABLE_DEBUG
+                int ext_len = buf[i++];
+#else
+                i++;
+#endif
+
+                if (i >= bytes) {
+                    i -= 2; /* rewind msg + ext_len for next chunk */
+                    goto out_chunk;
+                }
+                uint8_t ext_code = buf[i++];
+
+
+                switch (ext_code) {
+                case 1: /* SDTR (ignore body) */
+                    /* Body has 2 bytes, may span chunks: skip what we have */
+                    int skip = MIN(2, bytes - i);
+                    i += skip;
+                        /* If not all skipped this chunk, rest will arrive in next loop */
+                    break;
+                case 3: /* WDTR (ignore body) */
+                    if (i < bytes) {
+                        i++; /* skip one param byte if present this chunk */
+                    }
+                    break;
+                default:
+                    goto bad;
+                }
+                break;
+            }
+
+            /* TODO FIX QUEUE */
+            case 0x20: /* SIMPLE queue */
+                if (i < bytes) {
+                    s->select_tag |= buf[i++] | NCR710_TAG_VALID;
+                } else {
+                    /* Tag byte not in this chunk; rewind and reparse next loop */
+                    i--; /* put back msg */
+                    goto out_chunk;
+                }
+                break;
+
+            case 0x21: /* HEAD of queue (not implemented) */
+                BADF("HEAD queue not implemented\n");
+                if (i < bytes) {
+                    s->select_tag |= buf[i++] | NCR710_TAG_VALID;
+                } else {
+                    i--;
+                    goto out_chunk;
+                }
+                break;
+
+            case 0x22: /* ORDERED queue (not implemented) */
+                BADF("ORDERED queue not implemented\n");
+                if (i < bytes) {
+                    s->select_tag |= buf[i++] | NCR710_TAG_VALID;
+                } else {
+                    i--;
+                    goto out_chunk;
+                }
+                break;
+
+            case 0x0d: /* ABORT TAG */
+                if (current_req) {
+                    scsi_req_cancel(current_req->req);
+                }
+                ncr710_disconnect(s);
+                break;
+
+            case SCSI_MSG_ABORT: /* 0x06 - ABORT */
+            case 0x0e: /* CLEAR QUEUE */
+            case SCSI_MSG_BUS_DEVICE_RESET: /* 0x0c - BUS DEVICE RESET */
+
+                if (s->current) {
+                    scsi_req_cancel(s->current->req);
+                }
+                ncr710_disconnect(s);
+                break;
+
+            default:
+                if (msg & SCSI_MSG_IDENTIFY) {
+#if ENABLE_DEBUG
+                    bool disconnect_allowed = (msg & 0x40) != 0;
+#endif
+                    uint8_t lun = msg & 0x07;
+                    s->current_lun = lun;
+                    ncr710_set_phase(s, PHASE_CO);
+                    break;
+                }
+
+                goto bad;
+            }
+        }
+
+    out_chunk:
+        continue;
+    }
+
+    return;
+
+bad:
+    BADF("Unimplemented/Invalid message 0x%02x\n", s->sfbr);
+    ncr710_set_phase(s, PHASE_MI);
+    ncr710_add_msg_byte(s, 7); /* MESSAGE REJECT */
+    s->msg_action = NCR710_MSG_ACTION_NONE;
+}
+
+static void ncr710_memcpy(NCR710State *s, uint32_t dest, uint32_t src, int count)
+{
+
+    /* Direct memory to memory transfer using temporary buffer */
+    uint8_t buf[NCR710_BUF_SIZE];
+
+    while (count) {
+        int chunk = MIN(count, NCR710_BUF_SIZE);
+
+        /* Read from source */
+        ncr710_dma_read(s, src, buf, chunk);
+
+        /* Write to destination */
+        ncr710_dma_write(s, dest, buf, chunk);
+
+
+        src += chunk;
+        dest += chunk;
+        count -= chunk;
+    }
+}
+
+static void ncr710_wait_reselect(NCR710State *s)
+{
+
+    s->wait_reselect = true;
+    s->waiting = NCR710_WAIT_RESELECT;
+    s->script_active = false;  /* Pause SCRIPTS execution */
+
+    s->scntl1 &= ~NCR710_SCNTL1_CON;
+    s->istat &= ~NCR710_ISTAT_CON;
+
+}
+
+/* Timer callback to continue script execution */
+void ncr710_script_timer_callback(void *opaque)
+{
+    NCR710State *s = opaque;
+
+
+    if (s->script_active) {
+        ncr710_execute_script(s);
+    }
+}
+
+void ncr710_reselection_retry_callback(void *opaque)
+{
+    NCR710State *s = opaque;
+
+
+    if (!s->current || s->current->pending == 0) {
+        return;
+    }
+
+    if (s->waiting != NCR710_WAIT_RESELECT) {
+        return;
+    }
+
+    if (s->istat & (NCR710_ISTAT_SIP | NCR710_ISTAT_DIP)) {
+        timer_mod(s->reselection_retry_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
+        return;
+    }
+
+
+    NCR710Request *p = s->current;
+    uint32_t len = p->pending;
+    p->pending = 0;  /* Clear pending flag */
+
+    SCSIRequest *req = p->req;
+    s->command_complete = NCR710_CMD_PENDING;
+    p->dma_len = len;
+
+    s->scntl1 |= NCR710_SCNTL1_CON;
+    s->istat |= NCR710_ISTAT_CON;
+
+    s->sbcl = NCR710_SBCL_IO | NCR710_SBCL_CD | NCR710_SBCL_MSG |
+              NCR710_SBCL_BSY | NCR710_SBCL_SEL | NCR710_SBCL_REQ;
+
+    uint8_t host_id = (s->scid & 0x07);
+    if (req->dev->id == 0 && host_id == 0) {
+        s->sfbr = 0x00;
+    } else {
+        s->sfbr = (req->dev->id == 0 ? 0 : (1 << req->dev->id)) |
+                  (host_id == 0 ? 0 : (1 << host_id));
+    }
+
+    ncr710_set_phase(s, PHASE_MI);
+
+    uint8_t identify_msg = 0x80 | (req->lun & 0x07);
+    ncr710_add_msg_byte(s, identify_msg);
+
+    if (p->tag) {
+        ncr710_add_msg_byte(s, 0x20);  /* SIMPLE_TAG_MSG */
+        ncr710_add_msg_byte(s, p->tag & 0xff);
+    }
+
+    s->dsp = p->resume_offset - 8;
+
+    s->dsps = RESELECTED_DURING_SELECTION;  /* Set DSPS to 0x1000 */
+    s->sstat0 |= NCR710_SSTAT0_SEL;         /* Set SELECTED bit */
+    s->istat |= NCR710_ISTAT_SIP;           /* Set SCSI interrupt pending */
+    ncr710_update_irq(s);
+    s->waiting = NCR710_WAIT_NONE;
+}
+
+void ncr710_execute_script(NCR710State *s)
+{
+    uint32_t insn;
+    uint32_t addr;
+    int opcode;
+
+
+    s->script_active = 1;
+
+again:
+    insn = ncr710_read_dword(s, s->dsp);
+    if (!insn) {
+        /* If we receive an empty opcode increment the DSP by 4 bytes
+         * and execute the next opcode at that location */
+        s->dsp += 4;
+        goto again;
+    }
+    addr = ncr710_read_dword(s, s->dsp + 4);
+    s->dsps = addr;
+    s->dcmd = insn >> 24;
+    s->dsp += 8;
+    switch (insn >> 30) {
+    case 0: /* Block move.  */
+        if (s->sstat0 & NCR710_SSTAT0_STO) {
+            NCR710_DPRINTF("Delayed select timeout\n");
+            ncr710_stop_script(s);
+            ncr710_update_irq(s);
+            break;
+        }
+        s->dbc = insn & 0xffffff;
+        if (insn & (1 << 29)) {
+            /* Indirect addressing.  */
+            addr = ncr710_read_dword(s, addr);
+        } else if (insn & (1 << 28)) {
+            uint32_t buf[2];
+            int32_t offset;
+
+            /* 32-bit Table indirect */
+            offset = sextract32(addr, 0, 24);
+			ncr710_dma_read(s, s->dsa + offset, buf, 8);
+            /* byte count is stored in bits 0:23 only */
+            s->dbc = cpu_to_le32(buf[0]) & 0xffffff;
+            addr = cpu_to_le32(buf[1]);
+
+        }
+        /* Check phase match for block move instructions */
+        if ((s->sstat2 & PHASE_MASK) != ((insn >> 24) & 7)) {
+            uint8_t current_phase = s->sstat2 & PHASE_MASK;
+
+            ncr710_set_phase(s, current_phase);
+            s->sbcl |= NCR710_SBCL_REQ;
+            ncr710_script_scsi_interrupt(s, NCR710_SSTAT0_MA);
+            ncr710_stop_script(s);
+            break;
+        }
+
+        s->dnad = addr;
+        switch (s->sstat2 & 0x7) {
+        case PHASE_DO:
+            s->waiting = NCR710_WAIT_DMA;
+            ncr710_do_dma(s, 1);
+            break;
+        case PHASE_DI:
+            s->waiting = NCR710_WAIT_DMA;
+            ncr710_do_dma(s, 0);
+            if (s->waiting != NCR710_WAIT_NONE) {
+                /* Async - stop and wait */
+                break;
+            }
+            /* Sync - continue execution */
+            break;
+        case PHASE_CO:
+            ncr710_do_command(s);
+            break;
+        case PHASE_SI:
+            ncr710_do_status(s);
+            break;
+        case PHASE_MO:
+            ncr710_do_msgout(s);
+            break;
+        case PHASE_MI:
+            ncr710_do_msgin(s);
+            break;
+        default:
+            BADF("Unimplemented phase %d\n", s->sstat2 & PHASE_MASK);
+        }
+        s->ctest5 = (s->ctest5 & 0xfc) | ((s->dbc >> 8) & 3);
+        s->sbcl = s->dbc;
+        break;
+
+    case 1: /* IO or Read/Write instruction.  */
+        opcode = (insn >> 27) & 7;
+        if (opcode < 5) {
+            uint32_t id;
+
+            if (insn & (1 << 25)) {
+                id = ncr710_read_dword(s, s->dsa + sextract32(insn, 0, 24));
+            } else {
+                id = insn;
+            }
+            id = (id >> 16) & 0xff;
+            if (insn & (1 << 26)) {
+                addr = s->dsp + sextract32(addr, 0, 24);
+            }
+            s->dnad = addr;
+            switch (opcode) {
+            case 0: /* Select */
+                s->sdid = id;
+                if (s->scntl1 & NCR710_SCNTL1_CON) {
+                    if (insn & (1 << 24)) {
+                    } else {
+                        s->dsp = s->dnad;
+                        break;
+                    }
+                } else if (!scsi_device_find(&s->bus, 0, idbitstonum(id), 0)) {
+                    ncr710_bad_selection(s, id);
+                    break;
+                } else {
+
+                    /* ??? Linux drivers compain when this is set.  Maybe
+                     * it only applies in low-level mode (unimplemented).
+                     */
+                    s->select_tag = id << 8;
+                    s->scntl1 |= NCR710_SCNTL1_CON;
+
+                    if (insn & (1 << 24)) {
+                        s->socl |= NCR710_SOCL_ATN;
+                        ncr710_set_phase(s, PHASE_MO);
+                    } else {
+                        ncr710_set_phase(s, PHASE_CO);
+                    }
+                }
+                break;
+            case 1: /* Disconnect */
+
+                if (s->command_complete != NCR710_CMD_PENDING) {
+                    s->scntl1 &= ~NCR710_SCNTL1_CON;
+                    s->istat &= ~NCR710_ISTAT_CON;
+                    if (s->waiting == NCR710_WAIT_RESELECT) {
+                        s->waiting = NCR710_WAIT_NONE;
+                    }
+                } else {
+                    if (s->current) {
+                        s->current->resume_offset = s->dsp;
+                    }
+
+                    s->waiting = NCR710_WAIT_RESELECT;
+                    ncr710_stop_script(s);
+                    NCR710_DPRINTF("SCRIPTS paused at WAIT DISCONNECT\n");
+                }
+                break;
+            case 2: /* Wait Reselect */
+                if (!ncr710_irq_on_rsl(s)) {
+                    ncr710_wait_reselect(s);
+                }
+                break;
+            case 3: /* Set */
+                if (insn & (1 << 3)) {
+                    s->socl |= NCR710_SOCL_ATN;
+                    ncr710_set_phase(s, PHASE_MO);
+                }
+                if (insn & (1 << 9)) {
+                }
+                if (insn & (1 << 10))
+                    s->carry = 1;
+                break;
+            case 4: /* Clear */
+                if (insn & (1 << 3)) {
+                    s->socl &= ~NCR710_SOCL_ATN;
+                }
+                if (insn & (1 << 10))
+                    s->carry = 0;
+                break;
+            }
+        } else {
+            uint8_t op0;
+            uint8_t op1;
+            uint8_t data8;
+            int reg;
+            int xoperator;
+#if ENABLE_DEBUG
+            static const char *opcode_names[3] =
+                {"Write", "Read", "Read-Modify-Write"};
+            static const char *operator_names[8] =
+                {"MOV", "SHL", "OR", "XOR", "AND", "SHR", "ADD", "ADC"};
+#endif
+
+            reg = ((insn >> 16) & 0x7f) | (insn & 0x80);
+            data8 = (insn >> 8) & 0xff;
+            opcode = (insn >> 27) & 7;
+            xoperator = (insn >> 24) & 7;
+            op0 = op1 = 0;
+            switch (opcode) {
+            case 5: /* From SFBR */
+                op0 = s->sfbr;
+                op1 = data8;
+                break;
+            case 6: /* To SFBR */
+                if (xoperator)
+                    op0 = ncr710_reg_readb(s, reg);
+                op1 = data8;
+                break;
+            case 7: /* Read-modify-write */
+                if (xoperator)
+                    op0 = ncr710_reg_readb(s, reg);
+                if (insn & (1 << 23)) {
+                    op1 = s->sfbr;
+                } else {
+                    op1 = data8;
+                }
+                break;
+            }
+
+            switch (xoperator) {
+            case 0: /* move */
+                op0 = op1;
+                break;
+            case 1: /* Shift left */
+                op1 = op0 >> 7;
+                op0 = (op0 << 1) | s->carry;
+                s->carry = op1;
+                break;
+            case 2: /* OR */
+                op0 |= op1;
+                break;
+            case 3: /* XOR */
+                op0 ^= op1;
+                break;
+            case 4: /* AND */
+                op0 &= op1;
+                break;
+            case 5: /* SHR */
+                op1 = op0 & 1;
+                op0 = (op0 >> 1) | (s->carry << 7);
+                s->carry = op1;
+                break;
+            case 6: /* ADD */
+                op0 += op1;
+                s->carry = op0 < op1;
+                break;
+            case 7: /* ADC */
+                op0 += op1 + s->carry;
+                if (s->carry)
+                    s->carry = op0 <= op1;
+                else
+                    s->carry = op0 < op1;
+                break;
+            }
+
+            switch (opcode) {
+            case 5: /* From SFBR */
+            case 7: /* Read-modify-write */
+                ncr710_reg_writeb(s, reg, op0);
+                break;
+            case 6: /* To SFBR */
+                s->sfbr = op0;
+                break;
+            }
+        }
+        break;
+
+    case 2: /* Transfer Control.  */
+        {
+            int cond;
+            int jmp;
+
+            if ((insn & 0x002e0000) != 0) {
+            }
+            if (s->sstat0 & NCR710_SSTAT0_STO) {
+                break;
+            }
+            cond = jmp = (insn & (1 << 19)) != 0;
+            if (cond == jmp && (insn & (1 << 21))) {
+                cond = s->carry != 0;
+            }
+            if (cond == jmp && (insn & (1 << 17))) {
+                cond = (s->sstat2 & PHASE_MASK) == ((insn >> 24) & 7);
+            }
+            if (cond == jmp && (insn & (1 << 18))) {
+                uint8_t mask;
+
+                mask = (~insn >> 8) & 0xff;
+                cond = (s->sfbr & mask) == (insn & mask);
+            }
+            if (cond == jmp) {
+                if (insn & (1 << 23)) {
+                    /* Relative address.  */
+                    addr = s->dsp + sextract32(addr, 0, 24);
+                }
+                switch ((insn >> 27) & 7) {
+                case 0: /* Jump */
+                    s->dsp = addr;
+                    break;
+                case 1: /* Call */
+                    s->temp = s->dsp;
+                    s->dsp = addr;
+                    break;
+                case 2: /* Return */
+                    if (s->temp == 0) {
+                        ncr710_script_dma_interrupt(s, NCR710_DSTAT_IID);
+                        break;
+                    }
+                    s->dsp = s->temp;
+                    break;
+                case 3: /* Interrupt */
+                    if ((insn & (1 << 20)) != 0) {
+                        ncr710_update_irq(s);
+                    } else {
+                        if (s->dsps == GOOD_STATUS_AFTER_STATUS) {
+                            ncr710_script_dma_interrupt(s, NCR710_DSTAT_SIR);
+                            s->command_complete = NCR710_CMD_PENDING;
+                        } else {
+                            ncr710_script_dma_interrupt(s, NCR710_DSTAT_SIR);
+                        }
+                    }
+                    break;
+                default:
+                    ncr710_script_dma_interrupt(s, NCR710_DSTAT_IID);
+                    break;
+                }
+            } else {
+            }
+        }
+        break;
+
+    case 3:
+        if ((insn & (1 << 29)) == 0) {
+            /* Memory move.  */
+            uint32_t dest;
+            /* ??? The docs imply the destination address is loaded into
+               the TEMP register.  However the Linux drivers rely on
+               the value being presrved.  */
+            dest = ncr710_read_dword(s, s->dsp);
+            s->dsp += 4;
+            ncr710_memcpy(s, dest, addr, insn & 0xffffff);
+        } else {
+            uint8_t data[8];  /* Max 8 bytes for DSA/DSP registers */
+            int reg;
+            int n;
+            int i;
+#if ENABLE_DEBUG
+            uint32_t original_addr = addr;
+#endif
+            bool dsa_relative = (insn & (1 << 28)) != 0;
+            bool is_load = (insn & (1 << 24)) != 0;
+
+            if (dsa_relative) {
+                addr = s->dsa + sextract32(addr, 0, 24);
+            }
+
+            n = (insn & 7);
+            if (n == 0) n = 8;  /* 0 means 8 bytes */
+
+            reg = (insn >> 16) & 0xff;
+
+            if (is_load) {
+                ncr710_dma_read(s, addr, data, n);
+                for (i = 0; i < n; i++) {
+                }
+
+                for (i = 0; i < n; i++) {
+                    ncr710_reg_writeb(s, reg + i, data[i]);
+                }
+
+                if (reg == NCR710_DSA_REG && n == 4) {
+#if ENABLE_DEBUG
+                    uint32_t new_dsa = data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
+#endif
+                }
+            } else {
+                for (i = 0; i < n; i++) {
+                    data[i] = ncr710_reg_readb(s, reg + i);
+                }
+                ncr710_dma_write(s, addr, data, n);
+            }
+        }
+    }
+
+    if (s->script_active && s->waiting == NCR710_WAIT_NONE) {
+        if (s->dcntl & NCR710_DCNTL_SSM) {
+            ncr710_script_dma_interrupt(s, NCR710_DSTAT_SSI);
+            return;
+        } else {
+            goto again;
+        }
+    } else if (s->waiting == NCR710_WAIT_RESELECT) {
+        return;
+    } else if (s->waiting == NCR710_WAIT_DMA || s->waiting == NCR710_WAIT_RESERVED) {
+        if (s->command_complete == NCR710_CMD_COMPLETE) {
+            s->waiting = NCR710_WAIT_NONE;
+            goto again;
+        }
+        return;
+    }
+}
+
+static uint8_t ncr710_reg_readb(NCR710State *s, int offset)
+{
+    uint8_t ret = 0;
+
+#define CASE_GET_REG24(name, addr) \
+    case addr: ret = s->name & 0xff; break; \
+    case addr + 1: ret = (s->name >> 8) & 0xff; break; \
+    case addr + 2: ret = (s->name >> 16) & 0xff; break;
+
+#define CASE_GET_REG32(name, addr) \
+    case addr: ret = s->name & 0xff; break; \
+    case addr + 1: ret = (s->name >> 8) & 0xff; break; \
+    case addr + 2: ret = (s->name >> 16) & 0xff; break; \
+    case addr + 3: ret = (s->name >> 24) & 0xff; break;
+
+    switch (offset) {
+        case NCR710_SCNTL0_REG: /* SCNTL0 */
+            ret = s->scntl0;
+            break;
+        case NCR710_SCNTL1_REG: /* SCNTL1 */
+            ret = s->scntl1;
+            break;
+        case NCR710_SDID_REG: /* SDID */
+            ret = s->sdid;
+            break;
+        case NCR710_SIEN_REG: /* SIEN */
+            ret = s->sien0;
+            break;
+        case NCR710_SCID_REG:
+            ret = s->scid;
+            if ((ret & 0x7F) == 0) {
+                ret = 0x80 | NCR710_HOST_ID;
+            } else {
+                ret |= 0x80;
+            }
+            break;
+        case NCR710_SXFER_REG: /* SXFER */
+            ret = s->sxfer;
+            break;
+        case NCR710_SODL_REG: /* SODL */
+            ret = s->sodl;
+            break;
+        case NCR710_SOCL_REG: /* SOCL */
+            ret = s->socl;
+            break;
+        case NCR710_SFBR_REG: /* SFBR */
+            ret = s->sfbr;
+            break;
+        case NCR710_SIDL_REG: /* SIDL */
+            ret = s->sidl;
+            break;
+        case NCR710_SBDL_REG: /* SBDL */
+            ret = s->sbdl;
+            break;
+        case NCR710_SBCL_REG: /* SBCL */
+            ret = 0;
+            if (s->scntl1 & NCR710_SCNTL1_CON) {
+                ret = s->sstat2 & PHASE_MASK;
+                ret |= s->sbcl;
+                if (s->socl & NCR710_SOCL_ATN)
+                    ret |= NCR710_SBCL_ATN;
+            }
+            break;
+        case NCR710_DSTAT_REG: /* DSTAT */
+            ret = s->dstat;
+
+
+            /* We are not freeing s->current here:: driver needs it for completion processing.
+             * It will be freed when the next command starts.
+             */
+            if (s->dstat & NCR710_DSTAT_SIR) {
+            }
+            s->dstat = 0;  /* Clear all DMA interrupt status bits */
+            s->dstat |= NCR710_DSTAT_DFE;  /* Set DFE back after clearing (always "ready") */
+            s->istat &= ~NCR710_ISTAT_DIP;
+            ncr710_update_irq(s);
+
+            if (s->waiting == NCR710_WAIT_RESELECT && s->current && s->current->pending > 0) {
+                timer_mod(s->reselection_retry_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
+            }
+
+            if (!s->script_active && s->current && s->current->pending > 0 && s->command_complete == NCR710_CMD_COMPLETE) {
+                s->current->pending = 0;
+                s->waiting = NCR710_WAIT_NONE;
+                ncr710_execute_script(s);
+            }
+
+            if (s->waiting && s->current && s->current->pending > 0 && s->command_complete == NCR710_CMD_COMPLETE) {
+                s->current->pending = 0;
+                s->waiting = NCR710_WAIT_NONE;
+                ncr710_execute_script(s);
+            }
+
+            return ret;
+        case NCR710_SSTAT0_REG: /* SSTAT0 */
+            ret = s->sstat0;
+            if (s->sstat0 != 0 && !(s->sstat0 & NCR710_SSTAT0_STO)) {
+                s->sstat0 = 0;
+                s->istat &= ~NCR710_ISTAT_SIP;
+                ncr710_update_irq(s);
+                if (s->sbcl != 0) {
+                    s->sbcl = 0;
+                }
+            }
+            break;
+        case NCR710_SSTAT1_REG: /* SSTAT1 */
+            ret = s->sstat0;
+            break;
+        case NCR710_SSTAT2_REG: /* SSTAT2 */
+            ret = s->dstat;
+
+            if (s->dstat & NCR710_DSTAT_SIR) {
+            }
+            s->dstat = 0;
+            s->istat &= ~NCR710_ISTAT_DIP;
+            ncr710_update_irq(s);
+            break;
+        CASE_GET_REG32(dsa, NCR710_DSA_REG)
+            break;
+        case NCR710_CTEST0_REG: /* CTEST0 */
+            ret = s->ctest0;
+            break;
+        case NCR710_CTEST1_REG: /* CTEST1 */
+            ret = s->ctest1;
+            break;
+        case NCR710_CTEST2_REG: /* CTEST2 */
+            ret = s->ctest2;
+            s->ctest2 |= 0x04;
+            break;
+        case NCR710_CTEST3_REG: /* CTEST3 */
+            ret = s->ctest3;
+            if (!ncr710_scsi_fifo_empty(&s->scsi_fifo)) {
+                uint8_t parity;
+                ret = ncr710_scsi_fifo_dequeue(&s->scsi_fifo, &parity);
+                if (parity) {
+                    s->ctest2 |= 0x10;
+                } else {
+                    s->ctest2 &= ~0x10;
+                }
+            }
+            break;
+        case NCR710_CTEST4_REG: /* CTEST4 */
+            ret = s->ctest4;
+            break;
+        case NCR710_CTEST5_REG: /* CTEST5 */
+            ret = s->ctest5;
+            break;
+        case NCR710_CTEST6_REG: /* CTEST6 */
+            ret = s->ctest6;
+            break;
+        case NCR710_CTEST7_REG: /* CTEST7 */
+            ret = s->ctest7;
+            break;
+        CASE_GET_REG32(temp, NCR710_TEMP_REG)
+        case NCR710_DFIFO_REG: /* DFIFO */
+            ret = s->dfifo;
+            s->dfifo = 0;  /* DMA FIFO count is always 0 */
+            ret = s->dfifo;
+            break;
+        case NCR710_ISTAT_REG: /* ISTAT */
+            ret = s->istat;
+            break;
+        case NCR710_CTEST8_REG: /* CTEST8 */
+            ret = s->istat;
+            break;
+        case NCR710_LCRC_REG: /* LCRC */
+            ret = s->lcrc;
+            break;
+        CASE_GET_REG24(dbc, NCR710_DBC_REG)
+        case NCR710_DCMD_REG: /* DCMD */
+            ret = s->dcmd;
+            break;
+        CASE_GET_REG32(dnad, NCR710_DNAD_REG)
+        case NCR710_DSP_REG:
+            ret = s->dsp & 0xff;
+            break;
+        case NCR710_DSP_REG + 1:
+            ret = (s->dsp >> 8) & 0xff;
+            break;
+        case NCR710_DSP_REG + 2:
+            ret = (s->dsp >> 16) & 0xff;
+            break;
+        case NCR710_DSP_REG + 3:
+            ret = (s->dsp >> 24) & 0xff;
+            if (s->dsps == GOOD_STATUS_AFTER_STATUS && (s->dstat & NCR710_DSTAT_SIR)) {
+                s->dstat &= ~NCR710_DSTAT_SIR;
+                s->istat &= ~NCR710_ISTAT_DIP;
+                ncr710_update_irq(s);
+            }
+            break;
+        case NCR710_DSPS_REG:
+            ret = s->dsps & 0xff;
+            break;
+        case NCR710_DSPS_REG + 1:
+            ret = (s->dsps >> 8) & 0xff;
+            break;
+        case NCR710_DSPS_REG + 2:
+            ret = (s->dsps >> 16) & 0xff;
+            break;
+        case NCR710_DSPS_REG + 3:
+            ret = (s->dsps >> 24) & 0xff;
+            if (!(s->dstat & NCR710_DSTAT_SIR) && s->dsps != 0) {
+                s->dsps = 0;
+            }
+            break;
+        CASE_GET_REG32(scratch, NCR710_SCRATCH_REG)
+            break;
+        case NCR710_DMODE_REG: /* DMODE */
+            ret = s->dmode;
+            break;
+        case NCR710_DIEN_REG: /* DIEN */
+            ret = s->dien;
+            break;
+        case NCR710_DWT_REG: /* DWT */
+            ret = s->dwt;
+            break;
+        case NCR710_DCNTL_REG: /* DCNTL */
+            ret = s->dcntl;
+            return ret;
+        CASE_GET_REG32(adder, NCR710_ADDER_REG)
+            break;
+        default:
+            ret = 0;
+            break;
+    }
+
+#undef CASE_GET_REG24
+#undef CASE_GET_REG32
+    return ret;
+}
+
+static void ncr710_reg_writeb(NCR710State *s, int offset, uint8_t val)
+{
+    uint8_t old_val;
+
+#define CASE_SET_REG24(name, addr) \
+    case addr    : s->name &= 0xffffff00; s->name |= val;       break; \
+    case addr + 1: s->name &= 0xffff00ff; s->name |= val << 8;  break; \
+    case addr + 2: s->name &= 0xff00ffff; s->name |= val << 16; break;
+
+#define CASE_SET_REG32(name, addr) \
+    case addr    : s->name &= 0xffffff00; s->name |= val;       break; \
+    case addr + 1: s->name &= 0xffff00ff; s->name |= val << 8;  break; \
+    case addr + 2: s->name &= 0xff00ffff; s->name |= val << 16; break; \
+    case addr + 3: s->name &= 0x00ffffff; s->name |= val << 24; break;
+
+    trace_ncr710_reg_write(ncr710_reg_name(offset), offset, val);
+
+    switch (offset) {
+    case NCR710_SCNTL0_REG: /* SCNTL0 */
+        old_val = s->scntl0;
+        s->scntl0 = val;
+        break;
+
+    case NCR710_SCNTL1_REG: /* SCNTL1 */
+        old_val = s->scntl1;
+        s->scntl1 = val;
+
+        /* Handle Assert Even SCSI Parity (AESP) bit changes */
+        if ((val & NCR710_SCNTL1_AESP) != (old_val & NCR710_SCNTL1_AESP)) {
+            /* trace_ncr710_parity_sense_changed((val & NCR710_SCNTL1_AESP) != 0 ? "even" : "odd"); */
+        }
+
+        if (val & NCR710_SCNTL1_RST) {
+            if (!(s->sstat0 & NCR710_SSTAT0_RST)) {
+                s->sstat0 |= NCR710_SSTAT0_RST;
+                ncr710_script_scsi_interrupt(s, NCR710_SSTAT0_RST);
+            }
+            if (!(old_val & NCR710_SCNTL1_RST)) {
+                NCR710_DPRINTF("NCR710: SCNTL1: SCSI bus reset initiated\n");
+                ncr710_soft_reset(s);
+            }
+        } else {
+            s->sstat0 &= ~NCR710_SSTAT0_RST;
+        }
+        break;
+
+    case NCR710_SDID_REG: /* SDID */
+        s->sdid = val & 0x0F; /* Only lower 4 bits are valid */
+        break;
+
+    case NCR710_SIEN_REG: /* SIEN */
+        s->sien0 = val;
+        NCR710_DPRINTF("SIEN: interrupt mask=0x%02x\n", val);
+        ncr710_update_irq(s);
+        break;
+
+    case NCR710_SCID_REG: /* SCID */
+        s->scid = val;
+        break;
+
+    case NCR710_SXFER_REG: /* SXFER */
+        s->sxfer = val;
+        break;
+
+    case NCR710_SODL_REG: /* SODL */
+        s->sodl = val;
+        s->sstat1 |= NCR710_SSTAT1_ORF;
+        break;
+
+    case NCR710_SOCL_REG: /* SOCL */
+        s->socl = val;
+        break;
+
+    case NCR710_SFBR_REG: /* SFBR */
+        s->sfbr = val;
+        break;
+
+    case NCR710_SIDL_REG: /* SIDL */
+    case NCR710_SBDL_REG: /* SBDL */
+        break;
+
+    case NCR710_SBCL_REG: /* SBCL */
+        s->sbcl = val;
+        ncr710_set_phase(s, val & PHASE_MASK);
+        break;
+
+    case NCR710_DSTAT_REG:
+    case NCR710_SSTAT0_REG:
+    case NCR710_SSTAT1_REG:
+    case NCR710_SSTAT2_REG:
+        /* Linux writes to these read-only registers on startup */
+        return;
+
+    CASE_SET_REG32(dsa, NCR710_DSA_REG)
+        break;
+
+    case NCR710_CTEST0_REG: /* CTEST0 */
+        s->ctest0 = val;
+        break;
+
+    case NCR710_CTEST1_REG: /* CTEST1, read-only */
+        s->ctest1 = val;
+        break;
+
+    case NCR710_CTEST2_REG: /* CTEST2, read-only */
+        s->ctest2 = val;
+        break;
+
+    case NCR710_CTEST3_REG: /* CTEST3 */
+        s->ctest3 = val;
+        break;
+
+    case NCR710_CTEST4_REG: /* CTEST4 */
+        s->ctest4 = val;
+        break;
+
+    case NCR710_CTEST5_REG: /* CTEST5 */
+        s->ctest5 = val;
+        break;
+
+    case NCR710_CTEST6_REG: /* CTEST6 */
+        s->ctest6 = val;
+        /* No DMA FIFO to push to with direct transfers */
+        break;
+
+    case NCR710_CTEST7_REG: /* CTEST7 */
+        s->ctest7 = val;
+        break;
+
+    CASE_SET_REG32(temp, NCR710_TEMP_REG)
+
+    case NCR710_DFIFO_REG: /* DFIFO, read-only */
+        break;
+
+    case NCR710_ISTAT_REG: /* ISTAT */
+        old_val = s->istat;
+
+        if ((old_val & NCR710_ISTAT_DIP) && !(val & NCR710_ISTAT_DIP)) {
+            s->dstat = 0;
+            s->dsps = 0;
+        }
+
+        if ((old_val & NCR710_ISTAT_SIP) && !(val & NCR710_ISTAT_SIP)) {
+            s->sstat0 = 0;
+        }
+
+        s->istat = (val & ~(NCR710_ISTAT_DIP | NCR710_ISTAT_SIP)) |
+                  (s->istat & (NCR710_ISTAT_DIP | NCR710_ISTAT_SIP));
+        ncr710_update_irq(s);
+
+        if (val & NCR710_ISTAT_ABRT) {
+            ncr710_script_dma_interrupt(s, NCR710_DSTAT_ABRT);
+        }
+        break;
+
+    case NCR710_CTEST8_REG: /* CTEST8 */
+
+        if (val & 0x08) {
+            /* No DMA FIFO to flush with direct transfers */
+            s->dstat |= NCR710_DSTAT_DFE;  /* Set DMA FIFO Empty */
+        }
+        if (val & 0x04) {
+            ncr710_scsi_fifo_init(&s->scsi_fifo);
+            s->dstat |= NCR710_DSTAT_DFE;  /* Set DMA FIFO Empty */
+        }
+        break;
+    case NCR710_LCRC_REG: /* LCRC */
+        s->lcrc = val;
+        break;
+
+    CASE_SET_REG24(dbc, NCR710_DBC_REG)
+
+    case NCR710_DCMD_REG: /* DCMD */
+        s->dcmd = val;
+        break;
+
+    CASE_SET_REG32(dnad, NCR710_DNAD_REG)
+    case 0x2c: /* DSP[0:7] */
+        {
+            s->dsp &= 0xffffff00;
+            s->dsp |= val;
+        }
+        break;
+    case 0x2d: /* DSP[8:15] */
+        {
+            s->dsp &= 0xffff00ff;
+            s->dsp |= val << 8;
+        }
+        break;
+    case 0x2e: /* DSP[16:23] */
+        {
+            s->dsp &= 0xff00ffff;
+            s->dsp |= val << 16;
+        }
+        break;
+    case 0x2f: /* DSP[24:31] */
+        {
+            s->dsp &= 0x00ffffff;
+            s->dsp |= val << 24;
+
+            if (s->current && s->current->resume_offset != 0) {
+                if (s->dsp == s->current->resume_offset) {
+                } else {
+                }
+            }
+
+            s->waiting = NCR710_WAIT_NONE;
+            s->script_active = 1;
+            s->istat |= NCR710_ISTAT_CON;
+            ncr710_clear_selection_timeout(s);
+            ncr710_execute_script(s);
+        }
+        break;
+    CASE_SET_REG32(dsps, NCR710_DSPS_REG)
+    CASE_SET_REG32(scratch, NCR710_SCRATCH_REG)
+        break;
+
+    case NCR710_DMODE_REG: /* DMODE */
+        s->dmode = val;
+        break;
+
+    case NCR710_DIEN_REG: /* DIEN */
+        s->dien = val;
+        NCR710_DPRINTF("DIEN: interrupt enable=0x%02x\n", val);
+        ncr710_update_irq(s);
+        break;
+
+    case NCR710_DWT_REG: /* DWT */
+        s->dwt = val;
+        break;
+
+    case NCR710_DCNTL_REG: /* DCNTL */
+        s->dcntl = val & ~(NCR710_DCNTL_PFF);
+        if (val & NCR710_DCNTL_STD) {
+            s->waiting = NCR710_WAIT_NONE;
+            ncr710_execute_script(s);
+            s->dcntl &= ~NCR710_DCNTL_STD;
+        }
+        break;
+
+    CASE_SET_REG32(adder, NCR710_ADDER_REG)
+        break;
+
+    default:
+        break;
+    }
+
+#undef CASE_SET_REG24
+#undef CASE_SET_REG32
+}
+
+/* Memory region wrapper for NCR710 registers */
+uint64_t ncr710_reg_read(void *opaque, hwaddr addr, unsigned size)
+{
+    NCR710State *s = opaque;
+    uint8_t offset = addr & 0xff;
+    uint8_t val = ncr710_reg_readb(s, offset);
+    trace_ncr710_reg_read(ncr710_reg_name(offset), offset, val);
+    return val;
+}
+
+void ncr710_reg_write(void *opaque, hwaddr addr, uint64_t val, unsigned size)
+{
+    NCR710State *s = opaque;
+    uint8_t offset = addr & 0xff;
+    uint8_t val8 = val & 0xff;
+    ncr710_reg_writeb(s, offset, val8);
+}
+
+/* Device reset */
+static void ncr710_device_reset(DeviceState *dev)
+{
+    SysBusNCR710State *sysbus_dev = SYSBUS_NCR710_SCSI(dev);
+    NCR710State *s = &sysbus_dev->ncr710;
+
+    ncr710_soft_reset(s);
+}
+
+static const struct SCSIBusInfo ncr710_scsi_info = {
+    .tcq = true,
+    .max_target = 8,
+    .max_lun = 8,  /* LUN support buggy on linux? */
+
+    .transfer_data = ncr710_transfer_data,
+    .complete = ncr710_command_complete,
+    .cancel = ncr710_request_cancelled,
+};
+
+static const MemoryRegionOps ncr710_mmio_ops = {
+    .read = ncr710_reg_read,
+    .write = ncr710_reg_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+    .valid = {
+        .min_access_size = 1,
+        .max_access_size = 4,
+    },
+};
+
+static const VMStateDescription vmstate_ncr710_scsi_fifo = {
+    .name = "ncr710_scsi_fifo",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8_ARRAY(data, NCR710_SCSI_FIFO, NCR710_SCSI_FIFO_SIZE),
+        VMSTATE_UINT8_ARRAY(parity, NCR710_SCSI_FIFO, NCR710_SCSI_FIFO_SIZE),
+        VMSTATE_INT32(count, NCR710_SCSI_FIFO),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription vmstate_ncr710 = {
+    .name = "ncr710",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8(scntl0, NCR710State),
+        VMSTATE_UINT8(scntl1, NCR710State),
+        VMSTATE_UINT8(sdid, NCR710State),
+        VMSTATE_UINT8(sien0, NCR710State),
+        VMSTATE_UINT8(scid, NCR710State),
+        VMSTATE_UINT8(sxfer, NCR710State),
+        VMSTATE_UINT8(sodl, NCR710State),
+        VMSTATE_UINT8(socl, NCR710State),
+        VMSTATE_UINT8(sfbr, NCR710State),
+        VMSTATE_UINT8(sidl, NCR710State),
+        VMSTATE_UINT8(sbdl, NCR710State),
+        VMSTATE_UINT8(sbcl, NCR710State),
+        VMSTATE_UINT8(dstat, NCR710State),
+        VMSTATE_UINT8(sstat0, NCR710State),
+        VMSTATE_UINT8(sstat1, NCR710State),
+        VMSTATE_UINT8(sstat2, NCR710State),
+        VMSTATE_UINT8(ctest0, NCR710State),
+        VMSTATE_UINT8(ctest1, NCR710State),
+        VMSTATE_UINT8(ctest2, NCR710State),
+        VMSTATE_UINT8(ctest3, NCR710State),
+        VMSTATE_UINT8(ctest4, NCR710State),
+        VMSTATE_UINT8(ctest5, NCR710State),
+        VMSTATE_UINT8(ctest6, NCR710State),
+        VMSTATE_UINT8(ctest7, NCR710State),
+        VMSTATE_UINT8(ctest8, NCR710State),
+        VMSTATE_UINT32(temp, NCR710State),
+        VMSTATE_UINT8(dfifo, NCR710State),
+        VMSTATE_UINT8(istat, NCR710State),
+        VMSTATE_UINT8(lcrc, NCR710State),
+        VMSTATE_UINT8(dcmd, NCR710State),
+        VMSTATE_UINT8(dmode, NCR710State),
+        VMSTATE_UINT8(dien, NCR710State),
+        VMSTATE_UINT8(dwt, NCR710State),
+        VMSTATE_UINT8(dcntl, NCR710State),
+        VMSTATE_UINT32(dsa, NCR710State),
+        VMSTATE_UINT32(dbc, NCR710State),
+        VMSTATE_UINT32(dnad, NCR710State),
+        VMSTATE_UINT32(dsp, NCR710State),
+        VMSTATE_UINT32(dsps, NCR710State),
+        VMSTATE_UINT32(scratch, NCR710State),
+        VMSTATE_UINT32(adder, NCR710State),
+        VMSTATE_STRUCT(scsi_fifo, NCR710State, 1,
+            vmstate_ncr710_scsi_fifo, NCR710_SCSI_FIFO),
+        VMSTATE_UINT8(status, NCR710State),
+        VMSTATE_UINT8_ARRAY(msg, NCR710State,
+            NCR710_MAX_MSGIN_LEN),
+        VMSTATE_UINT8(msg_len, NCR710State),
+        VMSTATE_UINT8(msg_action, NCR710State),
+        VMSTATE_INT32(carry, NCR710State),
+        VMSTATE_BOOL(script_active, NCR710State),
+        VMSTATE_INT32(waiting, NCR710State),
+        VMSTATE_UINT8(command_complete, NCR710State),
+        VMSTATE_UINT32(select_tag, NCR710State),
+        VMSTATE_UINT8(current_lun, NCR710State),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription vmstate_sysbus_ncr710 = {
+    .name = "sysbus_ncr710",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_STRUCT(ncr710, SysBusNCR710State, 1, vmstate_ncr710, NCR710State),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+DeviceState *ncr710_device_create_sysbus(hwaddr addr, qemu_irq irq)
+{
+    DeviceState *dev;
+    SysBusDevice *sysbus;
+
+    dev = qdev_new(TYPE_SYSBUS_NCR710_SCSI);
+    sysbus = SYS_BUS_DEVICE(dev);
+
+    qdev_realize_and_unref(dev, NULL, &error_abort);
+    sysbus_mmio_map(sysbus, 0, addr);
+    sysbus_connect_irq(sysbus, 0, irq);
+    return dev;
+}
+
+DeviceState *ncr53c710_init(MemoryRegion *address_space, hwaddr addr, qemu_irq irq)
+{
+    DeviceState *dev;
+    SysBusDevice *sysbus;
+    SysBusNCR710State *s;
+
+    /* trace_ncr710_device_init(addr); */
+
+    dev = qdev_new(TYPE_SYSBUS_NCR710_SCSI);
+    sysbus = SYS_BUS_DEVICE(dev);
+
+    qdev_realize_and_unref(dev, NULL, &error_abort);
+    sysbus_mmio_map(sysbus, 0, addr);
+    sysbus_connect_irq(sysbus, 0, irq);
+
+    s = SYSBUS_NCR710_SCSI(dev);
+    if (!s->ncr710.as) {
+        s->ncr710.as = &address_space_memory;
+    }
+
+    return dev;
+}
+
+static void sysbus_ncr710_realize(DeviceState *dev, Error **errp)
+{
+    SysBusNCR710State *s = SYSBUS_NCR710_SCSI(dev);
+
+    trace_ncr710_device_realize();
+    scsi_bus_init(&s->ncr710.bus, sizeof(s->ncr710.bus), dev, &ncr710_scsi_info);
+    s->ncr710.as = &address_space_memory;
+
+    ncr710_scsi_fifo_init(&s->ncr710.scsi_fifo);
+    s->ncr710.dcntl &= ~NCR710_DCNTL_COM;
+    s->ncr710.scid = 0x80 | NCR710_HOST_ID;
+
+    s->ncr710.script_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
+                                         ncr710_script_timer_callback,
+                                         &s->ncr710);
+
+    s->ncr710.completion_irq_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
+                                                   ncr710_completion_irq_callback,
+                                                   &s->ncr710);
+
+    s->ncr710.reselection_retry_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
+                                                     ncr710_reselection_retry_callback,
+                                                     &s->ncr710);
+
+
+    memset(s->ncr710.msg, 0, sizeof(s->ncr710.msg));
+
+    memory_region_init_io(&s->iomem, OBJECT(s), &ncr710_mmio_ops, &s->ncr710,
+                          "ncr710", 0x100);
+    sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
+    sysbus_init_irq(SYS_BUS_DEVICE(s), &s->ncr710.irq);
+
+}
+
+static void sysbus_ncr710_init(Object *obj)
+{
+    SysBusNCR710State *s = SYSBUS_NCR710_SCSI(obj);
+    memset(&s->ncr710, 0, sizeof(NCR710State));
+    s->ncr710.ctest0 = 0x01;
+    s->ncr710.scid = 0x80 | NCR710_HOST_ID;
+    s->ncr710.dstat = NCR710_DSTAT_DFE;
+}
+
+static void sysbus_ncr710_class_init(ObjectClass *oc, const void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+
+    dc->realize = sysbus_ncr710_realize;
+    device_class_set_legacy_reset(dc, ncr710_device_reset);
+    dc->bus_type = NULL;
+    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
+    dc->desc = "NCR53C710 SCSI I/O Processor (SysBus)";
+    dc->vmsd = &vmstate_sysbus_ncr710;
+}
+
+static const TypeInfo sysbus_ncr710_info = {
+    .name = TYPE_SYSBUS_NCR710_SCSI,
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(SysBusNCR710State),
+    .instance_init = sysbus_ncr710_init,
+    .class_init = sysbus_ncr710_class_init,
+};
+
+/* Type registration */
+static void ncr710_register_types(void)
+{
+    type_register_static(&sysbus_ncr710_info);
+}
+
+type_init(ncr710_register_types)
diff --git a/hw/scsi/ncr53c710.h b/hw/scsi/ncr53c710.h
new file mode 100644
index 0000000000..6abb2dbd30
--- /dev/null
+++ b/hw/scsi/ncr53c710.h
@@ -0,0 +1,270 @@
+/*
+ * LASI NCR710 SCSI I/O Processor
+ *
+ * Copyright (c) 2025 Soumyajyotii Ssarkar <soumyajyotisarkar23@gmail.com>
+ *
+ * NCR710 SCSI I/O Processor implementation
+ * Based on the NCR53C710 Technical Manual Version 3.2, December 2000
+ *
+ * Developed from the hackish implementation of NCR53C710 by Helge Deller
+ * which was interim based on the hackish implementation by Toni Wilen for UAE
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef HW_NCR53C710_H
+#define HW_NCR53C710_H
+
+#include "qemu/osdep.h"
+#include "hw/sysbus.h"
+#include "hw/scsi/scsi.h"
+#include "qemu/fifo8.h"
+#include "qom/object.h"
+#include "system/memory.h"
+#include "hw/irq.h"
+#include "qemu/timer.h"
+
+#define TYPE_NCR710_SCSI "ncr710-scsi"
+#define TYPE_SYSBUS_NCR710_SCSI "sysbus-ncr710-scsi"
+
+#define SYSBUS_NCR710_SCSI(obj) \
+    OBJECT_CHECK(SysBusNCR710State, (obj), TYPE_SYSBUS_NCR710_SCSI)
+
+#define ENABLE_DEBUG 0
+#if ENABLE_DEBUG
+#define DBG(x)          x
+#define NCR710_DPRINTF(fmt, ...) \
+    fprintf(stderr, "QEMU: " fmt, ## __VA_ARGS__)
+#define BADF(fmt, ...) \
+    fprintf(stderr, "QEMU: error: " fmt, ## __VA_ARGS__)
+#else
+#define DBG(x)          do { } while (0)
+#define NCR710_DPRINTF(fmt, ...) do { } while (0)
+#define BADF(fmt, ...) do { } while (0)
+#endif
+
+/* NCR710 - Little Endian register Ordering */
+#define NCR710_SCNTL0_REG       0x00    /* SCSI Control Zero */
+#define NCR710_SCNTL1_REG       0x01    /* SCSI Control One */
+#define NCR710_SDID_REG         0x02    /* SCSI Destination ID */
+#define NCR710_SIEN_REG         0x03    /* SCSI Interrupt Enable */
+#define NCR710_SCID_REG         0x04    /* SCSI Chip ID */
+#define NCR710_SXFER_REG        0x05    /* SCSI Transfer */
+#define NCR710_SODL_REG         0x06    /* SCSI Output Data Latch */
+#define NCR710_SOCL_REG         0x07    /* SCSI Output Control Latch */
+#define NCR710_SFBR_REG         0x08    /* SCSI First Byte Received */
+#define NCR710_SIDL_REG         0x09    /* SCSI Input Data Latch */
+#define NCR710_SBDL_REG         0x0A    /* SCSI Bus Data Lines */
+#define NCR710_SBCL_REG         0x0B    /* SCSI Bus Control Lines */
+#define NCR710_DSTAT_REG        0x0C    /* DMA Status */
+#define NCR710_SSTAT0_REG       0x0D    /* SCSI Status Zero */
+#define NCR710_SSTAT1_REG       0x0E    /* SCSI Status One */
+#define NCR710_SSTAT2_REG       0x0F    /* SCSI Status Two */
+#define NCR710_DSA_REG          0x10    /* Data Structure Address */
+#define NCR710_CTEST0_REG       0x14    /* Chip Test Zero */
+#define NCR710_CTEST1_REG       0x15    /* Chip Test One */
+#define NCR710_CTEST2_REG       0x16    /* Chip Test Two */
+#define NCR710_CTEST3_REG       0x17    /* Chip Test Three */
+#define NCR710_CTEST4_REG       0x18    /* Chip Test Four */
+#define NCR710_CTEST5_REG       0x19    /* Chip Test Five */
+#define NCR710_CTEST6_REG       0x1A    /* Chip Test Six */
+#define NCR710_CTEST7_REG       0x1B    /* Chip Test Seven */
+#define NCR710_TEMP_REG         0x1C    /* Temporary Stack */
+#define NCR710_DFIFO_REG        0x20    /* DMA FIFO */
+#define NCR710_ISTAT_REG        0x21    /* Interrupt Status */
+#define NCR710_CTEST8_REG       0x22    /* Chip Test Eight */
+#define NCR710_LCRC_REG         0x23    /* Longitudinal Parity */
+#define NCR710_DBC_REG          0x24    /* DMA Byte Counter (24-bit, LE) */
+#define NCR710_DCMD_REG         0x27    /* DMA Command */
+#define NCR710_DNAD_REG         0x28    /* DMA Next Data Address (32-bit, LE) */
+#define NCR710_DSP_REG          0x2C    /* DMA SCRIPTS Pointer (32-bit, LE) */
+#define NCR710_DSPS_REG         0x30    /* DMA SCRIPTS Pointer Save (32-bit, LE) */
+#define NCR710_SCRATCH_REG      0x34    /* Scratch (32-bit, LE) */
+#define NCR710_DMODE_REG        0x38    /* DMA Mode */
+#define NCR710_DIEN_REG         0x39    /* DMA Interrupt Enable */
+#define NCR710_DWT_REG          0x3A    /* DMA Watchdog Timer */
+#define NCR710_DCNTL_REG        0x3B    /* DMA Control */
+#define NCR710_ADDER_REG        0x3C    /* Adder Sum Output (32-bit, LE) */
+
+/* NCR710 register size */
+#define NCR710_REG_SIZE         0x100
+
+/* Other constants */
+#define NCR710_BUF_SIZE         4096
+#define NCR710_HOST_ID          7
+#define NCR710_MAX_MSGIN_LEN    8
+#define NCR710_SCSI_FIFO_SIZE   8
+
+/* State enumerations for clearer code */
+typedef enum {
+    NCR710_WAIT_NONE = 0,           /* Not waiting, actively executing */
+    NCR710_WAIT_RESELECT = 1,       /* Waiting for reselection or disconnect */
+    NCR710_WAIT_DMA = 2,            /* Waiting for DMA operation to complete */
+    NCR710_WAIT_RESERVED = 3        /* Reserved state (currently unused) */
+} NCR710WaitState;
+
+typedef enum {
+    NCR710_CMD_PENDING = 0,         /* Command not yet complete */
+    NCR710_CMD_DATA_READY = 1,      /* Transfer data ready */
+    NCR710_CMD_COMPLETE = 2         /* Command fully complete */
+} NCR710CommandState;
+
+typedef enum {
+    NCR710_MSG_ACTION_NONE = 0,     /* No action, continue to command phase */
+    NCR710_MSG_ACTION_DISCONNECT = 1, /* Disconnect after message */
+    NCR710_MSG_ACTION_DATA_OUT = 2, /* Switch to data out phase */
+    NCR710_MSG_ACTION_DATA_IN = 3   /* Switch to data in phase */
+} NCR710MessageAction;
+
+/* Forward declarations */
+typedef struct NCR710State NCR710State;
+typedef struct NCR710Request NCR710Request;
+
+/* SCSI FIFO structure - 8 transfers deep, 1 byte per transfer (9-bit wide with parity) */
+typedef struct {
+    uint8_t data[NCR710_SCSI_FIFO_SIZE];    /* SCSI FIFO buffer (8 bytes deep) */
+    uint8_t parity[NCR710_SCSI_FIFO_SIZE];  /* Parity bits for each byte (9th bit) */
+    int head;                                /* Head pointer for dequeue (0-7) */
+    int count;                               /* Number of valid entries (0-8) */
+} NCR710_SCSI_FIFO;
+
+/* Request structure */
+struct NCR710Request {
+    SCSIRequest *req;
+    uint32_t tag;
+    uint32_t dma_len;
+    uint32_t pending;
+    uint8_t status;
+    bool active;
+    uint8_t *dma_buf;          /* DMA buffer pointer */
+    bool out;                  /* Direction flag: true for output, false for input */
+    uint32_t resume_offset;    /* SCRIPTS resume point after reselection */
+    uint32_t saved_dnad;       /* Saved DMA address for immediate reselection */
+};
+
+/* NCR710 State structure */
+struct NCR710State {
+    SysBusDevice parent_obj;
+
+    /* Memory and IRQ resources */
+    MemoryRegion mmio;
+    qemu_irq irq;
+
+    /* SCSI bus */
+    SCSIBus bus;
+    AddressSpace *as;
+
+    /* Registers */
+    uint8_t scntl0;
+    uint8_t scntl1;
+    uint8_t sdid;
+    uint8_t sien0;  /* Changed from sien */
+    uint8_t scid;
+    uint8_t sxfer;
+    uint8_t sodl;
+    uint8_t socl;
+    uint8_t sfbr;
+    uint8_t sidl;
+    uint8_t sbdl;
+    uint8_t sbcl;
+    uint8_t dstat;
+    uint8_t sstat0;
+    uint8_t sstat1;
+    uint8_t sstat2;
+    uint32_t dsa;
+    uint8_t ctest0;
+    uint8_t ctest1;
+    uint8_t ctest2;
+    uint8_t ctest3;
+    uint8_t ctest4;
+    uint8_t ctest5;
+    uint8_t ctest6;
+    uint8_t ctest7;
+    uint8_t ctest8;
+    uint32_t temp;
+    uint8_t dfifo;
+    uint8_t istat;
+    uint8_t lcrc;
+    uint32_t dbc;
+    uint8_t dcmd;
+    uint32_t dnad;
+    uint32_t dsp;
+    uint32_t dsps;
+    uint32_t scratch;
+    uint8_t dmode;
+    uint8_t dien;
+    uint8_t dwt;
+    uint8_t dcntl;
+    uint32_t adder;
+
+    /* FIFO */
+    NCR710_SCSI_FIFO scsi_fifo;
+
+    /* Current SCSI command state */
+    NCR710Request *current;
+    uint8_t status;
+    uint8_t msg[NCR710_MAX_MSGIN_LEN];
+    uint8_t msg_len;
+    uint8_t msg_action;         /* NCR710MessageAction values */
+    int carry;
+    bool script_active;
+    int32_t waiting;            /* NCR710WaitState values */
+    uint8_t command_complete;   /* NCR710CommandState values */
+
+    /* Script execution timer */
+    QEMUTimer *script_timer;
+    QEMUTimer *completion_irq_timer;
+    QEMUTimer *reselection_retry_timer;  /* Timer for deferred reselection retry */
+    uint32_t saved_dsps;
+
+
+    /* Additional required fields */
+    uint32_t select_tag;       /* Select tag for SCSI device selection */
+    uint8_t current_lun;       /* Current logical unit number */
+    uint8_t reselection_id;
+    bool wait_reselect;
+};
+
+/* Define SysBusNCR710State */
+typedef struct SysBusNCR710State {
+    SysBusDevice parent_obj;
+    MemoryRegion mmio;
+    MemoryRegion iomem;
+    qemu_irq irq;
+    NCR710State ncr710;
+} SysBusNCR710State;
+
+#define NCR710_REG_SIZE         0x100
+
+static inline NCR710State *ncr710_from_scsi_bus(SCSIBus *bus)
+{
+    return container_of(bus, NCR710State, bus);
+}
+
+static inline SysBusNCR710State *sysbus_from_ncr710(NCR710State *s)
+{
+    return container_of(s, SysBusNCR710State, ncr710);
+}
+
+DeviceState *ncr53c710_init(MemoryRegion *address_space, hwaddr addr, qemu_irq irq);
+DeviceState *ncr710_device_create_sysbus(hwaddr addr, qemu_irq irq);
+void ncr710_reg_write(void *opaque, hwaddr addr, uint64_t val, unsigned size);
+uint64_t ncr710_reg_read(void *opaque, hwaddr addr, unsigned size);
+void ncr710_soft_reset(NCR710State *s);
+
+/* NCR710 core SCSI callback functions */
+void ncr710_request_cancelled(SCSIRequest *req);
+void ncr710_command_complete(SCSIRequest *req, size_t resid);
+void ncr710_transfer_data(SCSIRequest *req, uint32_t len);
+void ncr710_execute_script(NCR710State *s);
+void ncr710_set_phase(NCR710State *s, int phase);
+
+/* NCR710 timer callbacks */
+void ncr710_script_timer_callback(void *opaque);
+void ncr710_completion_irq_callback(void *opaque);
+void ncr710_reselection_retry_callback(void *opaque);
+
+#endif /* HW_NCR53C710_H */
diff --git a/hw/scsi/trace-events b/hw/scsi/trace-events
index 6c2788e202..8cd6da6dae 100644
--- a/hw/scsi/trace-events
+++ b/hw/scsi/trace-events
@@ -306,6 +306,39 @@ lsi_reg_write(const char *name, int offset, uint8_t val) "Write reg %s 0x%x = 0x
 lsi_scripts_timer_triggered(void) "SCRIPTS timer triggered"
 lsi_scripts_timer_start(void) "SCRIPTS timer started"
 
+# ncr53c710.c
+ncr710_reset(void) "Reset"
+ncr710_reg_read(const char *name, int offset, uint8_t ret) "Read %s [0x%02x] = 0x%02x"
+ncr710_reg_write(const char *name, int offset, uint8_t val) "Write %s [0x%02x] = 0x%02x"
+ncr710_execute_script(uint32_t dsp, uint32_t insn, uint8_t opcode) "SCRIPTS pc=0x%08x insn=0x%08x op=0x%02x"
+ncr710_script_scsi_interrupt(uint8_t stat0, uint8_t sstat0) "SCSI interrupt stat=0x%02x sstat=0x%02x"
+ncr710_script_dma_interrupt(uint8_t stat, uint8_t dstat) "DMA interrupt stat=0x%02x dstat=0x%02x"
+ncr710_command_complete(uint32_t tag, uint8_t status) "tag=0x%x status=0x%02x"
+ncr710_transfer_data(uint32_t tag, uint32_t len, int waiting) "tag=0x%x len=%d waiting=%d"
+ncr710_disconnect(uint8_t waiting) "waiting=%d"
+ncr710_reselect(int target, uint32_t tag) "target=%d tag=0x%x"
+ncr710_bad_selection(uint32_t target) "target=%d"
+ncr710_wait_reselect(void) "Waiting for reselection"
+ncr710_device_realize(void) "Device realized"
+
+# lasi_ncr710.c
+lasi_ncr710_device_realize(void) "Device realized"
+lasi_ncr710_device_reset(void) "Device reset"
+lasi_ncr710_reg_read(uint32_t addr, uint32_t val, unsigned size) "addr=0x%03x val=0x%08x size=%u"
+lasi_ncr710_reg_write(uint32_t addr, uint32_t val, unsigned size) "addr=0x%03x val=0x%08x size=%u"
+lasi_ncr710_reg_read_id(uint32_t hw_type, uint32_t sversion, uint32_t val) "hw_type=%u sversion=0x%04x val=0x%08x"
+lasi_ncr710_timers_initialized(uint64_t script, uint64_t completion, uint64_t reselection) "Timers: script=0x%"PRIx64" completion=0x%"PRIx64" reselection=0x%"PRIx64
+lasi_ncr710_reg_read_hversion(uint32_t hversion) "LASI NCR710: HVersion read -> 0x%02x"
+lasi_ncr710_reg_read_scsi_id(uint32_t scsi_id) "LASI NCR710: SCSI ID read -> 0x%08x"
+lasi_ncr710_reg_forward_read(uint32_t addr, uint32_t val) "LASI NCR710: Forward read to NCR710 core addr=0x%03x val=0x%08x"
+lasi_ncr710_reg_forward_write(uint32_t addr, uint32_t val) "LASI NCR710: Forward write to NCR710 core addr=0x%03x val=0x%08x"
+lasi_ncr710_command_complete(uint32_t status, const char *status_name, size_t resid) "LASI NCR710: Command complete status=0x%02x (%s) resid=%zu"
+lasi_ncr710_transfer_data(uint32_t len) "LASI NCR710: Transfer data len=%u"
+lasi_ncr710_request_cancelled(void *req) "LASI NCR710: Request cancelled req=%p"
+lasi_ncr710_handle_legacy_cmdline(int busnr, int found_drives) "LASI NCR710: Handle legacy cmdline busnr=%d found_drives=%d"
+lasi_ncr710_legacy_drive_found(int busnr, int unit) "LASI NCR710: Found legacy drive at bus=%d unit=%d"
+lasi_ncr710_scsi_device_created(const char *type) "LASI NCR710: SCSI device created: %s"
+
 # virtio-scsi.c
 virtio_scsi_cmd_req(int lun, uint32_t tag, uint8_t cmd) "virtio_scsi_cmd_req lun=%u tag=0x%x cmd=0x%x"
 virtio_scsi_cmd_resp(int lun, uint32_t tag, int response, uint8_t status) "virtio_scsi_cmd_resp lun=%u tag=0x%x response=%d status=0x%x"
-- 
2.51.0



  reply	other threads:[~2025-10-17 20:09 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-17 20:06 [PATCH 00/10] HP-PARISC 715 machine with NCR710 SCSI chip deller
2025-10-17 20:06 ` deller [this message]
2025-10-22 10:57   ` [PATCH v3 #2a/10] Adding LASI's NCR710 SCSI Controller Wrapper Soumyajyotii Ssarkar
2025-10-22 10:57   ` [PATCH v3 #2b/10] Adding NCR710 SCSI Controller Core logic Soumyajyotii Ssarkar
2025-10-22 19:20   ` [PATCH 02/10] ncr710: Add driver for the NCR 53c710 SCSI chip Philippe Mathieu-Daudé
2025-10-22 20:00     ` Soumyajyotii Ssarkar
2025-10-17 20:06 ` [PATCH 03/10] lasi: Forward LASI SCSI ports to NCR 53c710 driver deller
2025-10-17 20:06 ` [PATCH 04/10] hw/scsi: Add config option for new ncr710 driver deller
2025-10-22 18:49   ` Richard Henderson
2025-10-17 20:06 ` [PATCH 05/10] hw/hppa: Fix firmware end address for LASI chip deller
2025-10-22 18:50   ` Richard Henderson
2025-10-17 20:06 ` [PATCH 06/10] hw/hppa: Fix interrupt of LASI parallel port deller
2025-10-22 18:50   ` Richard Henderson
2025-10-17 20:06 ` [PATCH 07/10] hw/hppa: Add the NCR 710 SCSI driver to hppa machines deller
2025-10-22 18:52   ` Richard Henderson
2025-10-17 20:06 ` [PATCH 08/10] hw/hppa: PCI devices depend on availability of PCI bus deller
2025-10-22 18:59   ` Richard Henderson
2025-10-17 20:06 ` [PATCH 09/10] hw/hppa: Require SeaBIOS version 19 for 715 machine deller
2025-10-22 19:00   ` Richard Henderson
2025-10-17 20:06 ` [PATCH 10/10] hw/hppa: Add 715 machine type including NCR710 SCSI deller
2025-10-22 19:10   ` Richard Henderson

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