xref: /openbmc/qemu/hw/char/debugcon.c (revision 8c1f72da)
1 /*
2  * QEMU Bochs-style debug console ("port E9") emulation
3  *
4  * Copyright (c) 2003-2004 Fabrice Bellard
5  * Copyright (c) 2008 Citrix Systems, Inc.
6  * Copyright (c) Intel Corporation; author: H. Peter Anvin
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a copy
9  * of this software and associated documentation files (the "Software"), to deal
10  * in the Software without restriction, including without limitation the rights
11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12  * copies of the Software, and to permit persons to whom the Software is
13  * furnished to do so, subject to the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in
16  * all copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24  * THE SOFTWARE.
25  */
26 
27 #include "hw/hw.h"
28 #include "sysemu/char.h"
29 #include "hw/isa/isa.h"
30 #include "hw/i386/pc.h"
31 
32 #define TYPE_ISA_DEBUGCON_DEVICE "isa-debugcon"
33 #define ISA_DEBUGCON_DEVICE(obj) \
34      OBJECT_CHECK(ISADebugconState, (obj), TYPE_ISA_DEBUGCON_DEVICE)
35 
36 //#define DEBUG_DEBUGCON
37 
38 typedef struct DebugconState {
39     MemoryRegion io;
40     CharDriverState *chr;
41     uint32_t readback;
42 } DebugconState;
43 
44 typedef struct ISADebugconState {
45     ISADevice parent_obj;
46 
47     uint32_t iobase;
48     DebugconState state;
49 } ISADebugconState;
50 
51 static void debugcon_ioport_write(void *opaque, hwaddr addr, uint64_t val,
52                                   unsigned width)
53 {
54     DebugconState *s = opaque;
55     unsigned char ch = val;
56 
57 #ifdef DEBUG_DEBUGCON
58     printf("debugcon: write addr=0x%04" HWADDR_PRIx " val=0x%02x\n", addr, val);
59 #endif
60 
61     qemu_chr_fe_write(s->chr, &ch, 1);
62 }
63 
64 
65 static uint64_t debugcon_ioport_read(void *opaque, hwaddr addr, unsigned width)
66 {
67     DebugconState *s = opaque;
68 
69 #ifdef DEBUG_DEBUGCON
70     printf("debugcon: read addr=0x%04x\n", addr);
71 #endif
72 
73     return s->readback;
74 }
75 
76 static const MemoryRegionOps debugcon_ops = {
77     .read = debugcon_ioport_read,
78     .write = debugcon_ioport_write,
79     .valid.min_access_size = 1,
80     .valid.max_access_size = 1,
81     .endianness = DEVICE_LITTLE_ENDIAN,
82 };
83 
84 static void debugcon_init_core(DebugconState *s)
85 {
86     if (!s->chr) {
87         fprintf(stderr, "Can't create debugcon device, empty char device\n");
88         exit(1);
89     }
90 
91     qemu_chr_add_handlers(s->chr, NULL, NULL, NULL, s);
92 }
93 
94 static int debugcon_isa_initfn(ISADevice *dev)
95 {
96     ISADebugconState *isa = ISA_DEBUGCON_DEVICE(dev);
97     DebugconState *s = &isa->state;
98 
99     debugcon_init_core(s);
100     memory_region_init_io(&s->io, &debugcon_ops, s,
101                           TYPE_ISA_DEBUGCON_DEVICE, 1);
102     memory_region_add_subregion(isa_address_space_io(dev),
103                                 isa->iobase, &s->io);
104     return 0;
105 }
106 
107 static Property debugcon_isa_properties[] = {
108     DEFINE_PROP_HEX32("iobase", ISADebugconState, iobase, 0xe9),
109     DEFINE_PROP_CHR("chardev",  ISADebugconState, state.chr),
110     DEFINE_PROP_HEX32("readback", ISADebugconState, state.readback, 0xe9),
111     DEFINE_PROP_END_OF_LIST(),
112 };
113 
114 static void debugcon_isa_class_initfn(ObjectClass *klass, void *data)
115 {
116     DeviceClass *dc = DEVICE_CLASS(klass);
117     ISADeviceClass *ic = ISA_DEVICE_CLASS(klass);
118     ic->init = debugcon_isa_initfn;
119     dc->props = debugcon_isa_properties;
120 }
121 
122 static const TypeInfo debugcon_isa_info = {
123     .name          = TYPE_ISA_DEBUGCON_DEVICE,
124     .parent        = TYPE_ISA_DEVICE,
125     .instance_size = sizeof(ISADebugconState),
126     .class_init    = debugcon_isa_class_initfn,
127 };
128 
129 static void debugcon_register_types(void)
130 {
131     type_register_static(&debugcon_isa_info);
132 }
133 
134 type_init(debugcon_register_types)
135