text: #ifndef HW_SYSBUS_H
  #define HW_SYSBUS_H
  
  /* Devices attached directly to the main system bus.  */
  
  #include "hw/qdev-core.h"
  #include "exec/memory.h"
  #include "qom/object.h"
  
  #define QDEV_MAX_MMIO 32
  #define QDEV_MAX_PIO 32
  
  #define TYPE_SYSTEM_BUS "System"
  DECLARE_INSTANCE_CHECKER(BusState, SYSTEM_BUS,
                           TYPE_SYSTEM_BUS)
  
  
  #define TYPE_SYS_BUS_DEVICE "sys-bus-device"
  OBJECT_DECLARE_TYPE(SysBusDevice, SysBusDeviceClass,
                      SYS_BUS_DEVICE)
  
  /**
   * SysBusDeviceClass:
   *
   * SysBusDeviceClass is not overriding #DeviceClass.realize, so derived
   * classes overriding it are not required to invoke its implementation.
   */
  
  #define SYSBUS_DEVICE_GPIO_IRQ "sysbus-irq"
  
  struct SysBusDeviceClass {
      /*< private >*/
      DeviceClass parent_class;
  
      /*
       * Let the sysbus device format its own non-PIO, non-MMIO unit address.
       *
       * Sometimes a class of SysBusDevices has neither MMIO nor PIO resources,
       * yet instances of it would like to distinguish themselves, in
       * OpenFirmware device paths, from other instances of the same class on the
       * sysbus. For that end we expose this callback.
       *
       * The implementation is not supposed to change *@dev, or incur other
       * observable change.
       *
       * The function returns a dynamically allocated string. On error, NULL
       * should be returned; the unit address portion of the OFW node will be
       * omitted then. (This is not considered a fatal error.)
       */
      char *(*explicit_ofw_unit_address)(const SysBusDevice *dev);
      void (*connect_irq_notifier)(SysBusDevice *dev, qemu_irq irq);
  };
  
  struct SysBusDevice {
      /*< private >*/
      DeviceState parent_obj;
      /*< public >*/
  
      int num_mmio;
      struct {
          hwaddr addr;
          MemoryRegion *memory;
      } mmio[QDEV_MAX_MMIO];
      int num_pio;
      uint32_t pio[QDEV_MAX_PIO];
  };
  
  typedef void FindSysbusDeviceFunc(SysBusDevice *sbdev, void *opaque);
  
  void sysbus_init_mmio(SysBusDevice *dev, MemoryRegion *memory);
  MemoryRegion *sysbus_mmio_get_region(SysBusDevice *dev, int n);
  void sysbus_init_irq(SysBusDevice *dev, qemu_irq *p);
  void sysbus_pass_irq(SysBusDevice *dev, SysBusDevice *target);
  void sysbus_init_ioports(SysBusDevice *dev, uint32_t ioport, uint32_t size);
  
  
  bool sysbus_has_irq(SysBusDevice *dev, int n);
  bool sysbus_has_mmio(SysBusDevice *dev, unsigned int n);
  void sysbus_connect_irq(SysBusDevice *dev, int n, qemu_irq irq);
  bool sysbus_is_irq_connected(SysBusDevice *dev, int n);
  qemu_irq sysbus_get_connected_irq(SysBusDevice *dev, int n);
  void sysbus_mmio_map(SysBusDevice *dev, int n, hwaddr addr);
  void sysbus_mmio_map_overlap(SysBusDevice *dev, int n, hwaddr addr,
                               int priority);
  void sysbus_mmio_unmap(SysBusDevice *dev, int n);
  void sysbus_add_io(SysBusDevice *dev, hwaddr addr,
                     MemoryRegion *mem);
  MemoryRegion *sysbus_address_space(SysBusDevice *dev);
  
  bool sysbus_realize(SysBusDevice *dev, Error **errp);
  bool sysbus_realize_and_unref(SysBusDevice *dev, Error **errp);
  
  /* Call func for every dynamically created sysbus device in the system */
  void foreach_dynamic_sysbus_device(FindSysbusDeviceFunc *func, void *opaque);
  
  /* Legacy helper function for creating devices.  */
  DeviceState *sysbus_create_varargs(const char *name,
                                   hwaddr addr, ...);
  
  static inline DeviceState *sysbus_create_simple(const char *name,
                                                hwaddr addr,
                                                qemu_irq irq)
  {
      return sysbus_create_varargs(name, addr, irq, NULL);
  }
  
  #endif /* HW_SYSBUS_H */
  