xref: /openbmc/qemu/hw/misc/debugexit.c (revision 073d9f2c)
1 /*
2  * debug exit port emulation
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation; either version 2 or
7  * (at your option) any later version.
8  */
9 
10 #include "qemu/osdep.h"
11 #include "hw/hw.h"
12 #include "hw/isa/isa.h"
13 
14 #define TYPE_ISA_DEBUG_EXIT_DEVICE "isa-debug-exit"
15 #define ISA_DEBUG_EXIT_DEVICE(obj) \
16      OBJECT_CHECK(ISADebugExitState, (obj), TYPE_ISA_DEBUG_EXIT_DEVICE)
17 
18 typedef struct ISADebugExitState {
19     ISADevice parent_obj;
20 
21     uint32_t iobase;
22     uint32_t iosize;
23     MemoryRegion io;
24 } ISADebugExitState;
25 
26 static uint64_t debug_exit_read(void *opaque, hwaddr addr, unsigned size)
27 {
28     return 0;
29 }
30 
31 static void debug_exit_write(void *opaque, hwaddr addr, uint64_t val,
32                              unsigned width)
33 {
34     exit((val << 1) | 1);
35 }
36 
37 static const MemoryRegionOps debug_exit_ops = {
38     .read = debug_exit_read,
39     .write = debug_exit_write,
40     .valid.min_access_size = 1,
41     .valid.max_access_size = 4,
42     .endianness = DEVICE_LITTLE_ENDIAN,
43 };
44 
45 static void debug_exit_realizefn(DeviceState *d, Error **errp)
46 {
47     ISADevice *dev = ISA_DEVICE(d);
48     ISADebugExitState *isa = ISA_DEBUG_EXIT_DEVICE(d);
49 
50     memory_region_init_io(&isa->io, OBJECT(dev), &debug_exit_ops, isa,
51                           TYPE_ISA_DEBUG_EXIT_DEVICE, isa->iosize);
52     memory_region_add_subregion(isa_address_space_io(dev),
53                                 isa->iobase, &isa->io);
54 }
55 
56 static Property debug_exit_properties[] = {
57     DEFINE_PROP_UINT32("iobase", ISADebugExitState, iobase, 0x501),
58     DEFINE_PROP_UINT32("iosize", ISADebugExitState, iosize, 0x02),
59     DEFINE_PROP_END_OF_LIST(),
60 };
61 
62 static void debug_exit_class_initfn(ObjectClass *klass, void *data)
63 {
64     DeviceClass *dc = DEVICE_CLASS(klass);
65 
66     dc->realize = debug_exit_realizefn;
67     dc->props = debug_exit_properties;
68     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
69 }
70 
71 static const TypeInfo debug_exit_info = {
72     .name          = TYPE_ISA_DEBUG_EXIT_DEVICE,
73     .parent        = TYPE_ISA_DEVICE,
74     .instance_size = sizeof(ISADebugExitState),
75     .class_init    = debug_exit_class_initfn,
76 };
77 
78 static void debug_exit_register_types(void)
79 {
80     type_register_static(&debug_exit_info);
81 }
82 
83 type_init(debug_exit_register_types)
84