text: #ifndef HW_SYSBUS_H
  #define HW_SYSBUS_H 1
  
  /* Devices attached directly to the main system bus.  */
  
  #include "hw/qdev.h"
  #include "exec/memory.h"
  
  #define QDEV_MAX_MMIO 32
  #define QDEV_MAX_PIO 32
  
  #define TYPE_SYSTEM_BUS "System"
  #define SYSTEM_BUS(obj) OBJECT_CHECK(BusState, (obj), TYPE_SYSTEM_BUS)
  
  typedef struct SysBusDevice SysBusDevice;
  
  #define TYPE_SYS_BUS_DEVICE "sys-bus-device"
  #define SYS_BUS_DEVICE(obj) \
       OBJECT_CHECK(SysBusDevice, (obj), TYPE_SYS_BUS_DEVICE)
  #define SYS_BUS_DEVICE_CLASS(klass) \
       OBJECT_CLASS_CHECK(SysBusDeviceClass, (klass), TYPE_SYS_BUS_DEVICE)
  #define SYS_BUS_DEVICE_GET_CLASS(obj) \
       OBJECT_GET_CLASS(SysBusDeviceClass, (obj), TYPE_SYS_BUS_DEVICE)
  
  /**
   * SysBusDeviceClass:
   * @init: Callback function invoked when the #DeviceState.realized property
   * is changed to %true. Deprecated, new types inheriting directly from
   * TYPE_SYS_BUS_DEVICE should use #DeviceClass.realize instead, new leaf
   * types should consult their respective parent type.
   *
   * 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"
  
  typedef struct SysBusDeviceClass {
      /*< private >*/
      DeviceClass parent_class;
      /*< public >*/
  
      int (*init)(SysBusDevice *dev);
  } SysBusDeviceClass;
  
  struct SysBusDevice {
      /*< private >*/
      DeviceState parent_obj;
      /*< public >*/
  
      int num_mmio;
      struct {
          hwaddr addr;
          MemoryRegion *memory;
      } mmio[QDEV_MAX_MMIO];
      int num_pio;
      pio_addr_t pio[QDEV_MAX_PIO];
  };
  
  typedef int 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, pio_addr_t ioport, pio_addr_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_add_io(SysBusDevice *dev, hwaddr addr,
                     MemoryRegion *mem);
  MemoryRegion *sysbus_address_space(SysBusDevice *dev);
  
  /* 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, ...);
  DeviceState *sysbus_try_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);
  }
  
  static inline DeviceState *sysbus_try_create_simple(const char *name,
                                                      hwaddr addr,
                                                      qemu_irq irq)
  {
      return sysbus_try_create_varargs(name, addr, irq, NULL);
  }
  
  #endif /* !HW_SYSBUS_H */
  