historical/m0-applesillicon.git/xnu-qemu-arm64-5.1.0/hw/nubus/nubus-bus.c
2024-01-16 11:20:27 -06:00

111 lines
2.6 KiB
C

/*
* QEMU Macintosh Nubus
*
* Copyright (c) 2013-2018 Laurent Vivier <laurent@vivier.eu>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "hw/nubus/nubus.h"
#include "hw/sysbus.h"
#include "qapi/error.h"
static NubusBus *nubus_find(void)
{
/* Returns NULL unless there is exactly one nubus device */
return NUBUS_BUS(object_resolve_path_type("", TYPE_NUBUS_BUS, NULL));
}
static void nubus_slot_write(void *opaque, hwaddr addr, uint64_t val,
unsigned int size)
{
/* read only */
}
static uint64_t nubus_slot_read(void *opaque, hwaddr addr,
unsigned int size)
{
return 0;
}
static const MemoryRegionOps nubus_slot_ops = {
.read = nubus_slot_read,
.write = nubus_slot_write,
.endianness = DEVICE_BIG_ENDIAN,
.valid = {
.min_access_size = 1,
.max_access_size = 1,
},
};
static void nubus_super_slot_write(void *opaque, hwaddr addr, uint64_t val,
unsigned int size)
{
/* read only */
}
static uint64_t nubus_super_slot_read(void *opaque, hwaddr addr,
unsigned int size)
{
return 0;
}
static const MemoryRegionOps nubus_super_slot_ops = {
.read = nubus_super_slot_read,
.write = nubus_super_slot_write,
.endianness = DEVICE_BIG_ENDIAN,
.valid = {
.min_access_size = 1,
.max_access_size = 1,
},
};
static void nubus_realize(BusState *bus, Error **errp)
{
if (!nubus_find()) {
error_setg(errp, "at most one %s device is permitted", TYPE_NUBUS_BUS);
return;
}
}
static void nubus_init(Object *obj)
{
NubusBus *nubus = NUBUS_BUS(obj);
memory_region_init_io(&nubus->super_slot_io, obj, &nubus_super_slot_ops,
nubus, "nubus-super-slots",
NUBUS_SUPER_SLOT_NB * NUBUS_SUPER_SLOT_SIZE);
memory_region_init_io(&nubus->slot_io, obj, &nubus_slot_ops,
nubus, "nubus-slots",
NUBUS_SLOT_NB * NUBUS_SLOT_SIZE);
nubus->current_slot = NUBUS_FIRST_SLOT;
}
static void nubus_class_init(ObjectClass *oc, void *data)
{
BusClass *bc = BUS_CLASS(oc);
bc->realize = nubus_realize;
}
static const TypeInfo nubus_bus_info = {
.name = TYPE_NUBUS_BUS,
.parent = TYPE_BUS,
.instance_size = sizeof(NubusBus),
.instance_init = nubus_init,
.class_init = nubus_class_init,
};
static void nubus_register_types(void)
{
type_register_static(&nubus_bus_info);
}
type_init(nubus_register_types)