hw/arm/armv7m.c - qemu - Git at Google

 /*
  * ARMV7M System emulation.
  *
  * Copyright (c) 2006-2007 CodeSourcery.
  * Written by Paul Brook
  *
  * This code is licensed under the GPL.
  */

 #include "qemu/osdep.h"
 #include "hw/arm/armv7m.h"
 #include "qapi/error.h"
 #include "hw/sysbus.h"
 #include "hw/arm/boot.h"
 #include "hw/loader.h"
 #include "hw/qdev-properties.h"
 #include "hw/qdev-clock.h"
 #include "elf.h"
 #include "sysemu/reset.h"
 #include "qemu/error-report.h"
 #include "qemu/module.h"
 #include "qemu/log.h"
 #include "target/arm/idau.h"
 #include "migration/vmstate.h"

 /* Bitbanded IO.  Each word corresponds to a single bit.  */

 /* Get the byte address of the real memory for a bitband access.  */
 static inline hwaddr bitband_addr(BitBandState *s, hwaddr offset)
 {
     return s->base | (offset & 0x1ffffff) >> 5;
 }

 static MemTxResult bitband_read(void *opaque, hwaddr offset,
                                 uint64_t *data, unsigned size, MemTxAttrs attrs)
 {
     BitBandState *s = opaque;
     uint8_t buf[4];
     MemTxResult res;
     int bitpos, bit;
     hwaddr addr;

     assert(size <= 4);

     /* Find address in underlying memory and round down to multiple of size */
     addr = bitband_addr(s, offset) & (-size);
     res = address_space_read(&s->source_as, addr, attrs, buf, size);
     if (res) {
         return res;
     }
     /* Bit position in the N bytes read... */
     bitpos = (offset >> 2) & ((size * 8) - 1);
     /* ...converted to byte in buffer and bit in byte */
     bit = (buf[bitpos >> 3] >> (bitpos & 7)) & 1;
     *data = bit;
     return MEMTX_OK;
 }

 static MemTxResult bitband_write(void *opaque, hwaddr offset, uint64_t value,
                                  unsigned size, MemTxAttrs attrs)
 {
     BitBandState *s = opaque;
     uint8_t buf[4];
     MemTxResult res;
     int bitpos, bit;
     hwaddr addr;

     assert(size <= 4);

     /* Find address in underlying memory and round down to multiple of size */
     addr = bitband_addr(s, offset) & (-size);
     res = address_space_read(&s->source_as, addr, attrs, buf, size);
     if (res) {
         return res;
     }
     /* Bit position in the N bytes read... */
     bitpos = (offset >> 2) & ((size * 8) - 1);
     /* ...converted to byte in buffer and bit in byte */
     bit = 1 << (bitpos & 7);
     if (value & 1) {
         buf[bitpos >> 3] |= bit;
     } else {
         buf[bitpos >> 3] &= ~bit;
     }
     return address_space_write(&s->source_as, addr, attrs, buf, size);
 }

 static const MemoryRegionOps bitband_ops = {
     .read_with_attrs = bitband_read,
     .write_with_attrs = bitband_write,
     .endianness = DEVICE_NATIVE_ENDIAN,
     .impl.min_access_size = 1,
     .impl.max_access_size = 4,
     .valid.min_access_size = 1,
     .valid.max_access_size = 4,
 };

 static void bitband_init(Object *obj)
 {
     BitBandState *s = BITBAND(obj);
     SysBusDevice *dev = SYS_BUS_DEVICE(obj);

     memory_region_init_io(&s->iomem, obj, &bitband_ops, s,
                           "bitband", 0x02000000);
     sysbus_init_mmio(dev, &s->iomem);
 }

 static void bitband_realize(DeviceState *dev, Error **errp)
 {
     BitBandState *s = BITBAND(dev);

     if (!s->source_memory) {
         error_setg(errp, "source-memory property not set");
         return;
     }

     address_space_init(&s->source_as, s->source_memory, "bitband-source");
 }

 /* Board init.  */

 static const hwaddr bitband_input_addr[ARMV7M_NUM_BITBANDS] = {
     0x20000000, 0x40000000
 };

 static const hwaddr bitband_output_addr[ARMV7M_NUM_BITBANDS] = {
     0x22000000, 0x42000000
 };

 static MemTxResult v7m_sysreg_ns_write(void *opaque, hwaddr addr,
                                        uint64_t value, unsigned size,
                                        MemTxAttrs attrs)
 {
     MemoryRegion *mr = opaque;

     if (attrs.secure) {
         /* S accesses to the alias act like NS accesses to the real region */
         attrs.secure = 0;
         return memory_region_dispatch_write(mr, addr, value,
                                             size_memop(size) | MO_TE, attrs);
     } else {
         /* NS attrs are RAZ/WI for privileged, and BusFault for user */
         if (attrs.user) {
             return MEMTX_ERROR;
         }
         return MEMTX_OK;
     }
 }

 static MemTxResult v7m_sysreg_ns_read(void *opaque, hwaddr addr,
                                       uint64_t *data, unsigned size,
                                       MemTxAttrs attrs)
 {
     MemoryRegion *mr = opaque;

     if (attrs.secure) {
         /* S accesses to the alias act like NS accesses to the real region */
         attrs.secure = 0;
         return memory_region_dispatch_read(mr, addr, data,
                                            size_memop(size) | MO_TE, attrs);
     } else {
         /* NS attrs are RAZ/WI for privileged, and BusFault for user */
         if (attrs.user) {
             return MEMTX_ERROR;
         }
         *data = 0;
         return MEMTX_OK;
     }
 }

 static const MemoryRegionOps v7m_sysreg_ns_ops = {
     .read_with_attrs = v7m_sysreg_ns_read,
     .write_with_attrs = v7m_sysreg_ns_write,
     .endianness = DEVICE_NATIVE_ENDIAN,
 };

 static MemTxResult v7m_systick_write(void *opaque, hwaddr addr,
                                      uint64_t value, unsigned size,
                                      MemTxAttrs attrs)
 {
     ARMv7MState *s = opaque;
     MemoryRegion *mr;

     /* Direct the access to the correct systick */
     mr = sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->systick[attrs.secure]), 0);
     return memory_region_dispatch_write(mr, addr, value,
                                         size_memop(size) | MO_TE, attrs);
 }

 static MemTxResult v7m_systick_read(void *opaque, hwaddr addr,
                                     uint64_t *data, unsigned size,
                                     MemTxAttrs attrs)
 {
     ARMv7MState *s = opaque;
     MemoryRegion *mr;

     /* Direct the access to the correct systick */
     mr = sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->systick[attrs.secure]), 0);
     return memory_region_dispatch_read(mr, addr, data, size_memop(size) | MO_TE,
                                        attrs);
 }

 static const MemoryRegionOps v7m_systick_ops = {
     .read_with_attrs = v7m_systick_read,
     .write_with_attrs = v7m_systick_write,
     .endianness = DEVICE_NATIVE_ENDIAN,
 };

 /*
  * Unassigned portions of the PPB space are RAZ/WI for privileged
  * accesses, and fault for non-privileged accesses.
  */
 static MemTxResult ppb_default_read(void *opaque, hwaddr addr,
                                     uint64_t *data, unsigned size,
                                     MemTxAttrs attrs)
 {
     qemu_log_mask(LOG_UNIMP, "Read of unassigned area of PPB: offset 0x%x\n",
                   (uint32_t)addr);
     if (attrs.user) {
         return MEMTX_ERROR;
     }
     *data = 0;
     return MEMTX_OK;
 }

 static MemTxResult ppb_default_write(void *opaque, hwaddr addr,
                                      uint64_t value, unsigned size,
                                      MemTxAttrs attrs)
 {
     qemu_log_mask(LOG_UNIMP, "Write of unassigned area of PPB: offset 0x%x\n",
                   (uint32_t)addr);
     if (attrs.user) {
         return MEMTX_ERROR;
     }
     return MEMTX_OK;
 }

 static const MemoryRegionOps ppb_default_ops = {
     .read_with_attrs = ppb_default_read,
     .write_with_attrs = ppb_default_write,
     .endianness = DEVICE_NATIVE_ENDIAN,
     .valid.min_access_size = 1,
     .valid.max_access_size = 8,
 };

 static void armv7m_instance_init(Object *obj)
 {
     ARMv7MState *s = ARMV7M(obj);
     int i;

     /* Can't init the cpu here, we don't yet know which model to use */

     memory_region_init(&s->container, obj, "armv7m-container", UINT64_MAX);

     object_initialize_child(obj, "nvic", &s->nvic, TYPE_NVIC);
     object_property_add_alias(obj, "num-irq",
                               OBJECT(&s->nvic), "num-irq");

     object_initialize_child(obj, "systick-reg-ns", &s->systick[M_REG_NS],
                             TYPE_SYSTICK);
     /*
      * We can't initialize the secure systick here, as we don't know
      * yet if we need it.
      */

     for (i = 0; i < ARRAY_SIZE(s->bitband); i++) {
         object_initialize_child(obj, "bitband[*]", &s->bitband[i],
                                 TYPE_BITBAND);
     }

     s->refclk = qdev_init_clock_in(DEVICE(obj), "refclk", NULL, NULL, 0);
     s->cpuclk = qdev_init_clock_in(DEVICE(obj), "cpuclk", NULL, NULL, 0);
 }

 static void armv7m_realize(DeviceState *dev, Error **errp)
 {
     ARMv7MState *s = ARMV7M(dev);
     SysBusDevice *sbd;
     Error *err = NULL;
     int i;

     if (!s->board_memory) {
         error_setg(errp, "memory property was not set");
         return;
     }

     /* cpuclk must be connected; refclk is optional */
     if (!clock_has_source(s->cpuclk)) {
         error_setg(errp, "armv7m: cpuclk must be connected");
         return;
     }

     memory_region_add_subregion_overlap(&s->container, 0, s->board_memory, -1);

     s->cpu = ARM_CPU(object_new_with_props(s->cpu_type, OBJECT(s), "cpu",
                                            &err, NULL));
     if (err != NULL) {
         error_propagate(errp, err);
         return;
     }

     object_property_set_link(OBJECT(s->cpu), "memory", OBJECT(&s->container),
                              &error_abort);
     if (object_property_find(OBJECT(s->cpu), "idau")) {
         object_property_set_link(OBJECT(s->cpu), "idau", s->idau,
                                  &error_abort);
     }
     if (object_property_find(OBJECT(s->cpu), "init-svtor")) {
         if (!object_property_set_uint(OBJECT(s->cpu), "init-svtor",
                                       s->init_svtor, errp)) {
             return;
         }
     }
     if (object_property_find(OBJECT(s->cpu), "init-nsvtor")) {
         if (!object_property_set_uint(OBJECT(s->cpu), "init-nsvtor",
                                       s->init_nsvtor, errp)) {
             return;
         }
     }
     if (object_property_find(OBJECT(s->cpu), "start-powered-off")) {
         if (!object_property_set_bool(OBJECT(s->cpu), "start-powered-off",
                                       s->start_powered_off, errp)) {
             return;
         }
     }
     if (object_property_find(OBJECT(s->cpu), "vfp")) {
         if (!object_property_set_bool(OBJECT(s->cpu), "vfp", s->vfp, errp)) {
             return;
         }
     }
     if (object_property_find(OBJECT(s->cpu), "dsp")) {
         if (!object_property_set_bool(OBJECT(s->cpu), "dsp", s->dsp, errp)) {
             return;
         }
     }

     /*
      * Tell the CPU where the NVIC is; it will fail realize if it doesn't
      * have one. Similarly, tell the NVIC where its CPU is.
      */
     s->cpu->env.nvic = &s->nvic;
     s->nvic.cpu = s->cpu;

     if (!qdev_realize(DEVICE(s->cpu), NULL, errp)) {
         return;
     }

     /* Note that we must realize the NVIC after the CPU */
     if (!sysbus_realize(SYS_BUS_DEVICE(&s->nvic), errp)) {
         return;
     }

     /* Alias the NVIC's input and output GPIOs as our own so the board
      * code can wire them up. (We do this in realize because the
      * NVIC doesn't create the input GPIO array until realize.)
      */
     qdev_pass_gpios(DEVICE(&s->nvic), dev, NULL);
     qdev_pass_gpios(DEVICE(&s->nvic), dev, "SYSRESETREQ");
     qdev_pass_gpios(DEVICE(&s->nvic), dev, "NMI");

     /*
      * We map various devices into the container MR at their architected
      * addresses. In particular, we map everything corresponding to the
      * "System PPB" space. This is the range from 0xe0000000 to 0xe00fffff
      * and includes the NVIC, the System Control Space (system registers),
      * the systick timer, and for CPUs with the Security extension an NS
      * banked version of all of these.
      *
      * The default behaviour for unimplemented registers/ranges
      * (for instance the Data Watchpoint and Trace unit at 0xe0001000)
      * is to RAZ/WI for privileged access and BusFault for non-privileged
      * access.
      *
      * The NVIC and System Control Space (SCS) starts at 0xe000e000
      * and looks like this:
      *  0x004 - ICTR
      *  0x010 - 0xff - systick
      *  0x100..0x7ec - NVIC
      *  0x7f0..0xcff - Reserved
      *  0xd00..0xd3c - SCS registers
      *  0xd40..0xeff - Reserved or Not implemented
      *  0xf00 - STIR
      *
      * Some registers within this space are banked between security states.
      * In v8M there is a second range 0xe002e000..0xe002efff which is the
      * NonSecure alias SCS; secure accesses to this behave like NS accesses
      * to the main SCS range, and non-secure accesses (including when
      * the security extension is not implemented) are RAZ/WI.
      * Note that both the main SCS range and the alias range are defined
      * to be exempt from memory attribution (R_BLJT) and so the memory
      * transaction attribute always matches the current CPU security
      * state (attrs.secure == env->v7m.secure). In the v7m_sysreg_ns_ops
      * wrappers we change attrs.secure to indicate the NS access; so
      * generally code determining which banked register to use should
      * use attrs.secure; code determining actual behaviour of the system
      * should use env->v7m.secure.
      *
      * Within the PPB space, some MRs overlap, and the priority
      * of overlapping regions is:
      *  - default region (for RAZ/WI and BusFault) : -1
      *  - system register regions (provided by the NVIC) : 0
      *  - systick : 1
      * This is because the systick device is a small block of registers
      * in the middle of the other system control registers.
      */

     memory_region_init_io(&s->defaultmem, OBJECT(s), &ppb_default_ops, s,
                           "nvic-default", 0x100000);
     memory_region_add_subregion_overlap(&s->container, 0xe0000000,
                                         &s->defaultmem, -1);

     /* Wire the NVIC up to the CPU */
     sbd = SYS_BUS_DEVICE(&s->nvic);
     sysbus_connect_irq(sbd, 0,
                        qdev_get_gpio_in(DEVICE(s->cpu), ARM_CPU_IRQ));

     memory_region_add_subregion(&s->container, 0xe000e000,
                                 sysbus_mmio_get_region(sbd, 0));
     if (arm_feature(&s->cpu->env, ARM_FEATURE_V8)) {
         /* Create the NS alias region for the NVIC sysregs */
         memory_region_init_io(&s->sysreg_ns_mem, OBJECT(s),
                               &v7m_sysreg_ns_ops,
                               sysbus_mmio_get_region(sbd, 0),
                               "nvic_sysregs_ns", 0x1000);
         memory_region_add_subregion(&s->container, 0xe002e000,
                                     &s->sysreg_ns_mem);
     }

     /*
      * Create and map the systick devices. Note that we only connect
      * refclk if it has been connected to us; otherwise the systick
      * device gets the wrong answer for clock_has_source(refclk), because
      * it has an immediate source (the ARMv7M's clock object) but not
      * an ultimate source, and then it won't correctly auto-select the
      * CPU clock as its only possible clock source.
      */
     if (clock_has_source(s->refclk)) {
         qdev_connect_clock_in(DEVICE(&s->systick[M_REG_NS]), "refclk",
                               s->refclk);
     }
     qdev_connect_clock_in(DEVICE(&s->systick[M_REG_NS]), "cpuclk", s->cpuclk);
     if (!sysbus_realize(SYS_BUS_DEVICE(&s->systick[M_REG_NS]), errp)) {
         return;
     }
     sysbus_connect_irq(SYS_BUS_DEVICE(&s->systick[M_REG_NS]), 0,
                        qdev_get_gpio_in_named(DEVICE(&s->nvic),
                                               "systick-trigger", M_REG_NS));

     if (arm_feature(&s->cpu->env, ARM_FEATURE_M_SECURITY)) {
         /*
          * We couldn't init the secure systick device in instance_init
          * as we didn't know then if the CPU had the security extensions;
          * so we have to do it here.
          */
         object_initialize_child(OBJECT(dev), "systick-reg-s",
                                 &s->systick[M_REG_S], TYPE_SYSTICK);
         if (clock_has_source(s->refclk)) {
             qdev_connect_clock_in(DEVICE(&s->systick[M_REG_S]), "refclk",
                                   s->refclk);
         }
         qdev_connect_clock_in(DEVICE(&s->systick[M_REG_S]), "cpuclk",
                               s->cpuclk);

         if (!sysbus_realize(SYS_BUS_DEVICE(&s->systick[M_REG_S]), errp)) {
             return;
         }
         sysbus_connect_irq(SYS_BUS_DEVICE(&s->systick[M_REG_S]), 0,
                            qdev_get_gpio_in_named(DEVICE(&s->nvic),
                                                   "systick-trigger", M_REG_S));
     }

     memory_region_init_io(&s->systickmem, OBJECT(s),
                           &v7m_systick_ops, s,
                           "v7m_systick", 0xe0);

     memory_region_add_subregion_overlap(&s->container, 0xe000e010,
                                         &s->systickmem, 1);
     if (arm_feature(&s->cpu->env, ARM_FEATURE_V8)) {
         memory_region_init_io(&s->systick_ns_mem, OBJECT(s),
                               &v7m_sysreg_ns_ops, &s->systickmem,
                               "v7m_systick_ns", 0xe0);
         memory_region_add_subregion_overlap(&s->container, 0xe002e010,
                                             &s->systick_ns_mem, 1);
     }

     /* If the CPU has RAS support, create the RAS register block */
     if (cpu_isar_feature(aa32_ras, s->cpu)) {
         object_initialize_child(OBJECT(dev), "armv7m-ras",
                                 &s->ras, TYPE_ARMV7M_RAS);
         sbd = SYS_BUS_DEVICE(&s->ras);
         if (!sysbus_realize(sbd, errp)) {
             return;
         }
         memory_region_add_subregion_overlap(&s->container, 0xe0005000,
                                             sysbus_mmio_get_region(sbd, 0), 1);
     }

     for (i = 0; i < ARRAY_SIZE(s->bitband); i++) {
         if (s->enable_bitband) {
             Object *obj = OBJECT(&s->bitband[i]);
             SysBusDevice *sbd = SYS_BUS_DEVICE(&s->bitband[i]);

             if (!object_property_set_int(obj, "base",
                                          bitband_input_addr[i], errp)) {
                 return;
             }
             object_property_set_link(obj, "source-memory",
                                      OBJECT(s->board_memory), &error_abort);
             if (!sysbus_realize(SYS_BUS_DEVICE(obj), errp)) {
                 return;
             }

             memory_region_add_subregion(&s->container, bitband_output_addr[i],
                                         sysbus_mmio_get_region(sbd, 0));
         } else {
             object_unparent(OBJECT(&s->bitband[i]));
         }
     }
 }

 static Property armv7m_properties[] = {
     DEFINE_PROP_STRING("cpu-type", ARMv7MState, cpu_type),
     DEFINE_PROP_LINK("memory", ARMv7MState, board_memory, TYPE_MEMORY_REGION,
                      MemoryRegion *),
     DEFINE_PROP_LINK("idau", ARMv7MState, idau, TYPE_IDAU_INTERFACE, Object *),
     DEFINE_PROP_UINT32("init-svtor", ARMv7MState, init_svtor, 0),
     DEFINE_PROP_UINT32("init-nsvtor", ARMv7MState, init_nsvtor, 0),
     DEFINE_PROP_BOOL("enable-bitband", ARMv7MState, enable_bitband, false),
     DEFINE_PROP_BOOL("start-powered-off", ARMv7MState, start_powered_off,
                      false),
     DEFINE_PROP_BOOL("vfp", ARMv7MState, vfp, true),
     DEFINE_PROP_BOOL("dsp", ARMv7MState, dsp, true),
     DEFINE_PROP_END_OF_LIST(),
 };

 static const VMStateDescription vmstate_armv7m = {
     .name = "armv7m",
     .version_id = 1,
     .minimum_version_id = 1,
     .fields = (VMStateField[]) {
         VMSTATE_CLOCK(refclk, ARMv7MState),
         VMSTATE_CLOCK(cpuclk, ARMv7MState),
         VMSTATE_END_OF_LIST()
     }
 };

 static void armv7m_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);

     dc->realize = armv7m_realize;
     dc->vmsd = &vmstate_armv7m;
     device_class_set_props(dc, armv7m_properties);
 }

 static const TypeInfo armv7m_info = {
     .name = TYPE_ARMV7M,
     .parent = TYPE_SYS_BUS_DEVICE,
     .instance_size = sizeof(ARMv7MState),
     .instance_init = armv7m_instance_init,
     .class_init = armv7m_class_init,
 };

 static void armv7m_reset(void *opaque)
 {
     ARMCPU *cpu = opaque;

     cpu_reset(CPU(cpu));
 }

 void armv7m_load_kernel(ARMCPU *cpu, const char *kernel_filename,
                         hwaddr mem_base, int mem_size)
 {
     ssize_t image_size;
     uint64_t entry;
     AddressSpace *as;
     int asidx;
     CPUState *cs = CPU(cpu);

     if (arm_feature(&cpu->env, ARM_FEATURE_EL3)) {
         asidx = ARMASIdx_S;
     } else {
         asidx = ARMASIdx_NS;
     }
     as = cpu_get_address_space(cs, asidx);

     if (kernel_filename) {
         image_size = load_elf_as(kernel_filename, NULL, NULL, NULL,
                                  &entry, NULL, NULL,
                                  NULL, 0, EM_ARM, 1, 0, as);
         if (image_size < 0) {
             image_size = load_image_targphys_as(kernel_filename, mem_base,
                                                 mem_size, as);
         }
         if (image_size < 0) {
             error_report("Could not load kernel '%s'", kernel_filename);
             exit(1);
         }
     }

     /* CPU objects (unlike devices) are not automatically reset on system
      * reset, so we must always register a handler to do so. Unlike
      * A-profile CPUs, we don't need to do anything special in the
      * handler to arrange that it starts correctly.
      * This is arguably the wrong place to do this, but it matches the
      * way A-profile does it. Note that this means that every M profile
      * board must call this function!
      */
     qemu_register_reset(armv7m_reset, cpu);
 }

 static Property bitband_properties[] = {
     DEFINE_PROP_UINT32("base", BitBandState, base, 0),
     DEFINE_PROP_LINK("source-memory", BitBandState, source_memory,
                      TYPE_MEMORY_REGION, MemoryRegion *),
     DEFINE_PROP_END_OF_LIST(),
 };

 static void bitband_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);

     dc->realize = bitband_realize;
     device_class_set_props(dc, bitband_properties);
 }

 static const TypeInfo bitband_info = {
     .name          = TYPE_BITBAND,
     .parent        = TYPE_SYS_BUS_DEVICE,
     .instance_size = sizeof(BitBandState),
     .instance_init = bitband_init,
     .class_init    = bitband_class_init,
 };

 static void armv7m_register_types(void)
 {
     type_register_static(&bitband_info);
     type_register_static(&armv7m_info);
 }

 type_init(armv7m_register_types)
	/*
	* ARMV7M System emulation.
	*
	* Copyright (c) 2006-2007 CodeSourcery.
	* Written by Paul Brook
	*
	* This code is licensed under the GPL.
	*/

	#include "qemu/osdep.h"
	#include "hw/arm/armv7m.h"
	#include "qapi/error.h"
	#include "hw/sysbus.h"
	#include "hw/arm/boot.h"
	#include "hw/loader.h"
	#include "hw/qdev-properties.h"
	#include "hw/qdev-clock.h"
	#include "elf.h"
	#include "sysemu/reset.h"
	#include "qemu/error-report.h"
	#include "qemu/module.h"
	#include "qemu/log.h"
	#include "target/arm/idau.h"
	#include "migration/vmstate.h"

	/* Bitbanded IO. Each word corresponds to a single bit. */

	/* Get the byte address of the real memory for a bitband access. */
	static inline hwaddr bitband_addr(BitBandState *s, hwaddr offset)
	{
	return s->base \| (offset & 0x1ffffff) >> 5;
	}

	static MemTxResult bitband_read(void *opaque, hwaddr offset,
	uint64_t *data, unsigned size, MemTxAttrs attrs)
	{
	BitBandState *s = opaque;
	uint8_t buf[4];
	MemTxResult res;
	int bitpos, bit;
	hwaddr addr;

	assert(size <= 4);

	/* Find address in underlying memory and round down to multiple of size */
	addr = bitband_addr(s, offset) & (-size);
	res = address_space_read(&s->source_as, addr, attrs, buf, size);
	if (res) {
	return res;
	}
	/* Bit position in the N bytes read... */
	bitpos = (offset >> 2) & ((size * 8) - 1);
	/* ...converted to byte in buffer and bit in byte */
	bit = (buf[bitpos >> 3] >> (bitpos & 7)) & 1;
	*data = bit;
	return MEMTX_OK;
	}

	static MemTxResult bitband_write(void *opaque, hwaddr offset, uint64_t value,
	unsigned size, MemTxAttrs attrs)
	{
	BitBandState *s = opaque;
	uint8_t buf[4];
	MemTxResult res;
	int bitpos, bit;
	hwaddr addr;

	assert(size <= 4);

	/* Find address in underlying memory and round down to multiple of size */
	addr = bitband_addr(s, offset) & (-size);
	res = address_space_read(&s->source_as, addr, attrs, buf, size);
	if (res) {
	return res;
	}
	/* Bit position in the N bytes read... */
	bitpos = (offset >> 2) & ((size * 8) - 1);
	/* ...converted to byte in buffer and bit in byte */
	bit = 1 << (bitpos & 7);
	if (value & 1) {
	buf[bitpos >> 3] \|= bit;
	} else {
	buf[bitpos >> 3] &= ~bit;
	}
	return address_space_write(&s->source_as, addr, attrs, buf, size);
	}

	static const MemoryRegionOps bitband_ops = {
	.read_with_attrs = bitband_read,
	.write_with_attrs = bitband_write,
	.endianness = DEVICE_NATIVE_ENDIAN,
	.impl.min_access_size = 1,
	.impl.max_access_size = 4,
	.valid.min_access_size = 1,
	.valid.max_access_size = 4,
	};

	static void bitband_init(Object *obj)
	{
	BitBandState *s = BITBAND(obj);
	SysBusDevice *dev = SYS_BUS_DEVICE(obj);

	memory_region_init_io(&s->iomem, obj, &bitband_ops, s,
	"bitband", 0x02000000);
	sysbus_init_mmio(dev, &s->iomem);
	}

	static void bitband_realize(DeviceState dev, Error *errp)
	{
	BitBandState *s = BITBAND(dev);

	if (!s->source_memory) {
	error_setg(errp, "source-memory property not set");
	return;
	}

	address_space_init(&s->source_as, s->source_memory, "bitband-source");
	}

	/* Board init. */

	static const hwaddr bitband_input_addr[ARMV7M_NUM_BITBANDS] = {
	0x20000000, 0x40000000
	};

	static const hwaddr bitband_output_addr[ARMV7M_NUM_BITBANDS] = {
	0x22000000, 0x42000000
	};

	static MemTxResult v7m_sysreg_ns_write(void *opaque, hwaddr addr,
	uint64_t value, unsigned size,
	MemTxAttrs attrs)
	{
	MemoryRegion *mr = opaque;

	if (attrs.secure) {
	/* S accesses to the alias act like NS accesses to the real region */
	attrs.secure = 0;
	return memory_region_dispatch_write(mr, addr, value,
	size_memop(size) \| MO_TE, attrs);
	} else {
	/* NS attrs are RAZ/WI for privileged, and BusFault for user */
	if (attrs.user) {
	return MEMTX_ERROR;
	}
	return MEMTX_OK;
	}
	}

	static MemTxResult v7m_sysreg_ns_read(void *opaque, hwaddr addr,
	uint64_t *data, unsigned size,
	MemTxAttrs attrs)
	{
	MemoryRegion *mr = opaque;

	if (attrs.secure) {
	/* S accesses to the alias act like NS accesses to the real region */
	attrs.secure = 0;
	return memory_region_dispatch_read(mr, addr, data,
	size_memop(size) \| MO_TE, attrs);
	} else {
	/* NS attrs are RAZ/WI for privileged, and BusFault for user */
	if (attrs.user) {
	return MEMTX_ERROR;
	}
	*data = 0;
	return MEMTX_OK;
	}
	}

	static const MemoryRegionOps v7m_sysreg_ns_ops = {
	.read_with_attrs = v7m_sysreg_ns_read,
	.write_with_attrs = v7m_sysreg_ns_write,
	.endianness = DEVICE_NATIVE_ENDIAN,
	};

	static MemTxResult v7m_systick_write(void *opaque, hwaddr addr,
	uint64_t value, unsigned size,
	MemTxAttrs attrs)
	{
	ARMv7MState *s = opaque;
	MemoryRegion *mr;

	/* Direct the access to the correct systick */
	mr = sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->systick[attrs.secure]), 0);
	return memory_region_dispatch_write(mr, addr, value,
	size_memop(size) \| MO_TE, attrs);
	}

	static MemTxResult v7m_systick_read(void *opaque, hwaddr addr,
	uint64_t *data, unsigned size,
	MemTxAttrs attrs)
	{
	ARMv7MState *s = opaque;
	MemoryRegion *mr;

	/* Direct the access to the correct systick */
	mr = sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->systick[attrs.secure]), 0);
	return memory_region_dispatch_read(mr, addr, data, size_memop(size) \| MO_TE,
	attrs);
	}

	static const MemoryRegionOps v7m_systick_ops = {
	.read_with_attrs = v7m_systick_read,
	.write_with_attrs = v7m_systick_write,
	.endianness = DEVICE_NATIVE_ENDIAN,
	};

	/*
	* Unassigned portions of the PPB space are RAZ/WI for privileged
	* accesses, and fault for non-privileged accesses.
	*/
	static MemTxResult ppb_default_read(void *opaque, hwaddr addr,
	uint64_t *data, unsigned size,
	MemTxAttrs attrs)
	{
	qemu_log_mask(LOG_UNIMP, "Read of unassigned area of PPB: offset 0x%x\n",
	(uint32_t)addr);
	if (attrs.user) {
	return MEMTX_ERROR;
	}
	*data = 0;
	return MEMTX_OK;
	}

	static MemTxResult ppb_default_write(void *opaque, hwaddr addr,
	uint64_t value, unsigned size,
	MemTxAttrs attrs)
	{
	qemu_log_mask(LOG_UNIMP, "Write of unassigned area of PPB: offset 0x%x\n",
	(uint32_t)addr);
	if (attrs.user) {
	return MEMTX_ERROR;
	}
	return MEMTX_OK;
	}

	static const MemoryRegionOps ppb_default_ops = {
	.read_with_attrs = ppb_default_read,
	.write_with_attrs = ppb_default_write,
	.endianness = DEVICE_NATIVE_ENDIAN,
	.valid.min_access_size = 1,
	.valid.max_access_size = 8,
	};

	static void armv7m_instance_init(Object *obj)
	{
	ARMv7MState *s = ARMV7M(obj);
	int i;

	/* Can't init the cpu here, we don't yet know which model to use */

	memory_region_init(&s->container, obj, "armv7m-container", UINT64_MAX);

	object_initialize_child(obj, "nvic", &s->nvic, TYPE_NVIC);
	object_property_add_alias(obj, "num-irq",
	OBJECT(&s->nvic), "num-irq");

	object_initialize_child(obj, "systick-reg-ns", &s->systick[M_REG_NS],
	TYPE_SYSTICK);
	/*
	* We can't initialize the secure systick here, as we don't know
	* yet if we need it.
	*/

	for (i = 0; i < ARRAY_SIZE(s->bitband); i++) {
	object_initialize_child(obj, "bitband[*]", &s->bitband[i],
	TYPE_BITBAND);
	}

	s->refclk = qdev_init_clock_in(DEVICE(obj), "refclk", NULL, NULL, 0);
	s->cpuclk = qdev_init_clock_in(DEVICE(obj), "cpuclk", NULL, NULL, 0);
	}

	static void armv7m_realize(DeviceState dev, Error *errp)
	{
	ARMv7MState *s = ARMV7M(dev);
	SysBusDevice *sbd;
	Error *err = NULL;
	int i;

	if (!s->board_memory) {
	error_setg(errp, "memory property was not set");
	return;
	}

	/* cpuclk must be connected; refclk is optional */
	if (!clock_has_source(s->cpuclk)) {
	error_setg(errp, "armv7m: cpuclk must be connected");
	return;
	}

	memory_region_add_subregion_overlap(&s->container, 0, s->board_memory, -1);

	s->cpu = ARM_CPU(object_new_with_props(s->cpu_type, OBJECT(s), "cpu",
	&err, NULL));
	if (err != NULL) {
	error_propagate(errp, err);
	return;
	}

	object_property_set_link(OBJECT(s->cpu), "memory", OBJECT(&s->container),
	&error_abort);
	if (object_property_find(OBJECT(s->cpu), "idau")) {
	object_property_set_link(OBJECT(s->cpu), "idau", s->idau,
	&error_abort);
	}
	if (object_property_find(OBJECT(s->cpu), "init-svtor")) {
	if (!object_property_set_uint(OBJECT(s->cpu), "init-svtor",
	s->init_svtor, errp)) {
	return;
	}
	}
	if (object_property_find(OBJECT(s->cpu), "init-nsvtor")) {
	if (!object_property_set_uint(OBJECT(s->cpu), "init-nsvtor",
	s->init_nsvtor, errp)) {
	return;
	}
	}
	if (object_property_find(OBJECT(s->cpu), "start-powered-off")) {
	if (!object_property_set_bool(OBJECT(s->cpu), "start-powered-off",
	s->start_powered_off, errp)) {
	return;
	}
	}
	if (object_property_find(OBJECT(s->cpu), "vfp")) {
	if (!object_property_set_bool(OBJECT(s->cpu), "vfp", s->vfp, errp)) {
	return;
	}
	}
	if (object_property_find(OBJECT(s->cpu), "dsp")) {
	if (!object_property_set_bool(OBJECT(s->cpu), "dsp", s->dsp, errp)) {
	return;
	}
	}

	/*
	* Tell the CPU where the NVIC is; it will fail realize if it doesn't
	* have one. Similarly, tell the NVIC where its CPU is.
	*/
	s->cpu->env.nvic = &s->nvic;
	s->nvic.cpu = s->cpu;

	if (!qdev_realize(DEVICE(s->cpu), NULL, errp)) {
	return;
	}

	/* Note that we must realize the NVIC after the CPU */
	if (!sysbus_realize(SYS_BUS_DEVICE(&s->nvic), errp)) {
	return;
	}

	/* Alias the NVIC's input and output GPIOs as our own so the board
	* code can wire them up. (We do this in realize because the
	* NVIC doesn't create the input GPIO array until realize.)
	*/
	qdev_pass_gpios(DEVICE(&s->nvic), dev, NULL);
	qdev_pass_gpios(DEVICE(&s->nvic), dev, "SYSRESETREQ");
	qdev_pass_gpios(DEVICE(&s->nvic), dev, "NMI");

	/*
	* We map various devices into the container MR at their architected
	* addresses. In particular, we map everything corresponding to the
	* "System PPB" space. This is the range from 0xe0000000 to 0xe00fffff
	* and includes the NVIC, the System Control Space (system registers),
	* the systick timer, and for CPUs with the Security extension an NS
	* banked version of all of these.
	*
	* The default behaviour for unimplemented registers/ranges
	* (for instance the Data Watchpoint and Trace unit at 0xe0001000)
	* is to RAZ/WI for privileged access and BusFault for non-privileged
	* access.
	*
	* The NVIC and System Control Space (SCS) starts at 0xe000e000
	* and looks like this:
	* 0x004 - ICTR
	* 0x010 - 0xff - systick
	* 0x100..0x7ec - NVIC
	* 0x7f0..0xcff - Reserved
	* 0xd00..0xd3c - SCS registers
	* 0xd40..0xeff - Reserved or Not implemented
	* 0xf00 - STIR
	*
	* Some registers within this space are banked between security states.
	* In v8M there is a second range 0xe002e000..0xe002efff which is the
	* NonSecure alias SCS; secure accesses to this behave like NS accesses
	* to the main SCS range, and non-secure accesses (including when
	* the security extension is not implemented) are RAZ/WI.
	* Note that both the main SCS range and the alias range are defined
	* to be exempt from memory attribution (R_BLJT) and so the memory
	* transaction attribute always matches the current CPU security
	* state (attrs.secure == env->v7m.secure). In the v7m_sysreg_ns_ops
	* wrappers we change attrs.secure to indicate the NS access; so
	* generally code determining which banked register to use should
	* use attrs.secure; code determining actual behaviour of the system
	* should use env->v7m.secure.
	*
	* Within the PPB space, some MRs overlap, and the priority
	* of overlapping regions is:
	* - default region (for RAZ/WI and BusFault) : -1
	* - system register regions (provided by the NVIC) : 0
	* - systick : 1
	* This is because the systick device is a small block of registers
	* in the middle of the other system control registers.
	*/

	memory_region_init_io(&s->defaultmem, OBJECT(s), &ppb_default_ops, s,
	"nvic-default", 0x100000);
	memory_region_add_subregion_overlap(&s->container, 0xe0000000,
	&s->defaultmem, -1);

	/* Wire the NVIC up to the CPU */
	sbd = SYS_BUS_DEVICE(&s->nvic);
	sysbus_connect_irq(sbd, 0,
	qdev_get_gpio_in(DEVICE(s->cpu), ARM_CPU_IRQ));

	memory_region_add_subregion(&s->container, 0xe000e000,
	sysbus_mmio_get_region(sbd, 0));
	if (arm_feature(&s->cpu->env, ARM_FEATURE_V8)) {
	/* Create the NS alias region for the NVIC sysregs */
	memory_region_init_io(&s->sysreg_ns_mem, OBJECT(s),
	&v7m_sysreg_ns_ops,
	sysbus_mmio_get_region(sbd, 0),
	"nvic_sysregs_ns", 0x1000);
	memory_region_add_subregion(&s->container, 0xe002e000,
	&s->sysreg_ns_mem);
	}

	/*
	* Create and map the systick devices. Note that we only connect
	* refclk if it has been connected to us; otherwise the systick
	* device gets the wrong answer for clock_has_source(refclk), because
	* it has an immediate source (the ARMv7M's clock object) but not
	* an ultimate source, and then it won't correctly auto-select the
	* CPU clock as its only possible clock source.
	*/
	if (clock_has_source(s->refclk)) {
	qdev_connect_clock_in(DEVICE(&s->systick[M_REG_NS]), "refclk",
	s->refclk);
	}
	qdev_connect_clock_in(DEVICE(&s->systick[M_REG_NS]), "cpuclk", s->cpuclk);
	if (!sysbus_realize(SYS_BUS_DEVICE(&s->systick[M_REG_NS]), errp)) {
	return;
	}
	sysbus_connect_irq(SYS_BUS_DEVICE(&s->systick[M_REG_NS]), 0,
	qdev_get_gpio_in_named(DEVICE(&s->nvic),
	"systick-trigger", M_REG_NS));

	if (arm_feature(&s->cpu->env, ARM_FEATURE_M_SECURITY)) {
	/*
	* We couldn't init the secure systick device in instance_init
	* as we didn't know then if the CPU had the security extensions;
	* so we have to do it here.
	*/
	object_initialize_child(OBJECT(dev), "systick-reg-s",
	&s->systick[M_REG_S], TYPE_SYSTICK);
	if (clock_has_source(s->refclk)) {
	qdev_connect_clock_in(DEVICE(&s->systick[M_REG_S]), "refclk",
	s->refclk);
	}
	qdev_connect_clock_in(DEVICE(&s->systick[M_REG_S]), "cpuclk",
	s->cpuclk);

	if (!sysbus_realize(SYS_BUS_DEVICE(&s->systick[M_REG_S]), errp)) {
	return;
	}
	sysbus_connect_irq(SYS_BUS_DEVICE(&s->systick[M_REG_S]), 0,
	qdev_get_gpio_in_named(DEVICE(&s->nvic),
	"systick-trigger", M_REG_S));
	}

	memory_region_init_io(&s->systickmem, OBJECT(s),
	&v7m_systick_ops, s,
	"v7m_systick", 0xe0);

	memory_region_add_subregion_overlap(&s->container, 0xe000e010,
	&s->systickmem, 1);
	if (arm_feature(&s->cpu->env, ARM_FEATURE_V8)) {
	memory_region_init_io(&s->systick_ns_mem, OBJECT(s),
	&v7m_sysreg_ns_ops, &s->systickmem,
	"v7m_systick_ns", 0xe0);
	memory_region_add_subregion_overlap(&s->container, 0xe002e010,
	&s->systick_ns_mem, 1);
	}

	/* If the CPU has RAS support, create the RAS register block */
	if (cpu_isar_feature(aa32_ras, s->cpu)) {
	object_initialize_child(OBJECT(dev), "armv7m-ras",
	&s->ras, TYPE_ARMV7M_RAS);
	sbd = SYS_BUS_DEVICE(&s->ras);
	if (!sysbus_realize(sbd, errp)) {
	return;
	}
	memory_region_add_subregion_overlap(&s->container, 0xe0005000,
	sysbus_mmio_get_region(sbd, 0), 1);
	}

	for (i = 0; i < ARRAY_SIZE(s->bitband); i++) {
	if (s->enable_bitband) {
	Object *obj = OBJECT(&s->bitband[i]);
	SysBusDevice *sbd = SYS_BUS_DEVICE(&s->bitband[i]);

	if (!object_property_set_int(obj, "base",
	bitband_input_addr[i], errp)) {
	return;
	}
	object_property_set_link(obj, "source-memory",
	OBJECT(s->board_memory), &error_abort);
	if (!sysbus_realize(SYS_BUS_DEVICE(obj), errp)) {
	return;
	}

	memory_region_add_subregion(&s->container, bitband_output_addr[i],
	sysbus_mmio_get_region(sbd, 0));
	} else {
	object_unparent(OBJECT(&s->bitband[i]));
	}
	}
	}

	static Property armv7m_properties[] = {
	DEFINE_PROP_STRING("cpu-type", ARMv7MState, cpu_type),
	DEFINE_PROP_LINK("memory", ARMv7MState, board_memory, TYPE_MEMORY_REGION,
	MemoryRegion *),
	DEFINE_PROP_LINK("idau", ARMv7MState, idau, TYPE_IDAU_INTERFACE, Object *),
	DEFINE_PROP_UINT32("init-svtor", ARMv7MState, init_svtor, 0),
	DEFINE_PROP_UINT32("init-nsvtor", ARMv7MState, init_nsvtor, 0),
	DEFINE_PROP_BOOL("enable-bitband", ARMv7MState, enable_bitband, false),
	DEFINE_PROP_BOOL("start-powered-off", ARMv7MState, start_powered_off,
	false),
	DEFINE_PROP_BOOL("vfp", ARMv7MState, vfp, true),
	DEFINE_PROP_BOOL("dsp", ARMv7MState, dsp, true),
	DEFINE_PROP_END_OF_LIST(),
	};

	static const VMStateDescription vmstate_armv7m = {
	.name = "armv7m",
	.version_id = 1,
	.minimum_version_id = 1,
	.fields = (VMStateField[]) {
	VMSTATE_CLOCK(refclk, ARMv7MState),
	VMSTATE_CLOCK(cpuclk, ARMv7MState),
	VMSTATE_END_OF_LIST()
	}
	};

	static void armv7m_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);

	dc->realize = armv7m_realize;
	dc->vmsd = &vmstate_armv7m;
	device_class_set_props(dc, armv7m_properties);
	}

	static const TypeInfo armv7m_info = {
	.name = TYPE_ARMV7M,
	.parent = TYPE_SYS_BUS_DEVICE,
	.instance_size = sizeof(ARMv7MState),
	.instance_init = armv7m_instance_init,
	.class_init = armv7m_class_init,
	};

	static void armv7m_reset(void *opaque)
	{
	ARMCPU *cpu = opaque;

	cpu_reset(CPU(cpu));
	}

	void armv7m_load_kernel(ARMCPU cpu, const char kernel_filename,
	hwaddr mem_base, int mem_size)
	{
	ssize_t image_size;
	uint64_t entry;
	AddressSpace *as;
	int asidx;
	CPUState *cs = CPU(cpu);

	if (arm_feature(&cpu->env, ARM_FEATURE_EL3)) {
	asidx = ARMASIdx_S;
	} else {
	asidx = ARMASIdx_NS;
	}
	as = cpu_get_address_space(cs, asidx);

	if (kernel_filename) {
	image_size = load_elf_as(kernel_filename, NULL, NULL, NULL,
	&entry, NULL, NULL,
	NULL, 0, EM_ARM, 1, 0, as);
	if (image_size < 0) {
	image_size = load_image_targphys_as(kernel_filename, mem_base,
	mem_size, as);
	}
	if (image_size < 0) {
	error_report("Could not load kernel '%s'", kernel_filename);
	exit(1);
	}
	}

	/* CPU objects (unlike devices) are not automatically reset on system
	* reset, so we must always register a handler to do so. Unlike
	* A-profile CPUs, we don't need to do anything special in the
	* handler to arrange that it starts correctly.
	* This is arguably the wrong place to do this, but it matches the
	* way A-profile does it. Note that this means that every M profile
	* board must call this function!
	*/
	qemu_register_reset(armv7m_reset, cpu);
	}

	static Property bitband_properties[] = {
	DEFINE_PROP_UINT32("base", BitBandState, base, 0),
	DEFINE_PROP_LINK("source-memory", BitBandState, source_memory,
	TYPE_MEMORY_REGION, MemoryRegion *),
	DEFINE_PROP_END_OF_LIST(),
	};

	static void bitband_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);

	dc->realize = bitband_realize;
	device_class_set_props(dc, bitband_properties);
	}

	static const TypeInfo bitband_info = {
	.name = TYPE_BITBAND,
	.parent = TYPE_SYS_BUS_DEVICE,
	.instance_size = sizeof(BitBandState),
	.instance_init = bitband_init,
	.class_init = bitband_class_init,
	};

	static void armv7m_register_types(void)
	{
	type_register_static(&bitband_info);
	type_register_static(&armv7m_info);
	}

	type_init(armv7m_register_types)