xref: /openbmc/qemu/hw/char/debugcon.c (revision c7bcc85d)
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%02" PRIx64 "]\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%04" HWADDR_PRIx "\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_realize_core(DebugconState *s, Error **errp)
85 {
86     if (!s->chr) {
87         error_setg(errp, "Can't create debugcon device, empty char device");
88         return;
89     }
90 
91     qemu_chr_add_handlers(s->chr, NULL, NULL, NULL, s);
92 }
93 
94 static void debugcon_isa_realizefn(DeviceState *dev, Error **errp)
95 {
96     ISADevice *d = ISA_DEVICE(dev);
97     ISADebugconState *isa = ISA_DEBUGCON_DEVICE(dev);
98     DebugconState *s = &isa->state;
99     Error *err = NULL;
100 
101     debugcon_realize_core(s, &err);
102     if (err != NULL) {
103         error_propagate(errp, err);
104         return;
105     }
106     memory_region_init_io(&s->io, OBJECT(dev), &debugcon_ops, s,
107                           TYPE_ISA_DEBUGCON_DEVICE, 1);
108     memory_region_add_subregion(isa_address_space_io(d),
109                                 isa->iobase, &s->io);
110 }
111 
112 static Property debugcon_isa_properties[] = {
113     DEFINE_PROP_UINT32("iobase", ISADebugconState, iobase, 0xe9),
114     DEFINE_PROP_CHR("chardev",  ISADebugconState, state.chr),
115     DEFINE_PROP_UINT32("readback", ISADebugconState, state.readback, 0xe9),
116     DEFINE_PROP_END_OF_LIST(),
117 };
118 
119 static void debugcon_isa_class_initfn(ObjectClass *klass, void *data)
120 {
121     DeviceClass *dc = DEVICE_CLASS(klass);
122 
123     dc->realize = debugcon_isa_realizefn;
124     dc->props = debugcon_isa_properties;
125     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
126 }
127 
128 static const TypeInfo debugcon_isa_info = {
129     .name          = TYPE_ISA_DEBUGCON_DEVICE,
130     .parent        = TYPE_ISA_DEVICE,
131     .instance_size = sizeof(ISADebugconState),
132     .class_init    = debugcon_isa_class_initfn,
133 };
134 
135 static void debugcon_register_types(void)
136 {
137     type_register_static(&debugcon_isa_info);
138 }
139 
140 type_init(debugcon_register_types)
141