qemu/hw/empty_slot.c

91 lines
2.2 KiB
C
Raw Normal View History

/*
* QEMU Empty Slot
*
* The empty_slot device emulates known to a bus but not connected devices.
*
* Copyright (c) 2010 Artyom Tarasenko
*
* This code is licensed under the GNU GPL v2 or (at your option) any later
* version.
*/
#include "hw.h"
#include "sysbus.h"
#include "empty_slot.h"
//#define DEBUG_EMPTY_SLOT
#ifdef DEBUG_EMPTY_SLOT
#define DPRINTF(fmt, ...) \
do { printf("empty_slot: " fmt , ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...) do {} while (0)
#endif
typedef struct EmptySlot {
SysBusDevice busdev;
MemoryRegion iomem;
uint64_t size;
} EmptySlot;
static uint64_t empty_slot_read(void *opaque, target_phys_addr_t addr,
unsigned size)
{
DPRINTF("read from " TARGET_FMT_plx "\n", addr);
return 0;
}
static void empty_slot_write(void *opaque, target_phys_addr_t addr,
uint64_t val, unsigned size)
{
DPRINTF("write 0x%x to " TARGET_FMT_plx "\n", (unsigned)val, addr);
}
static const MemoryRegionOps empty_slot_ops = {
.read = empty_slot_read,
.write = empty_slot_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
void empty_slot_init(target_phys_addr_t addr, uint64_t slot_size)
{
if (slot_size > 0) {
/* Only empty slots larger than 0 byte need handling. */
DeviceState *dev;
SysBusDevice *s;
EmptySlot *e;
dev = qdev_create(NULL, "empty_slot");
s = sysbus_from_qdev(dev);
e = FROM_SYSBUS(EmptySlot, s);
e->size = slot_size;
qdev_init_nofail(dev);
sysbus_mmio_map(s, 0, addr);
}
}
static int empty_slot_init1(SysBusDevice *dev)
{
EmptySlot *s = FROM_SYSBUS(EmptySlot, dev);
memory_region_init_io(&s->iomem, &empty_slot_ops, s,
"empty-slot", s->size);
sysbus_init_mmio(dev, &s->iomem);
return 0;
}
static SysBusDeviceInfo empty_slot_info = {
.init = empty_slot_init1,
.qdev.name = "empty_slot",
.qdev.size = sizeof(EmptySlot),
};
static void empty_slot_register_devices(void)
{
sysbus_register_withprop(&empty_slot_info);
}
device_init(empty_slot_register_devices);