hw/char/debugcon.c

   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 "qemu/osdep.h"
  28 #include "qapi/error.h"
  29 #include "hw/hw.h"
  30 #include "chardev/char-fe.h"
  31 #include "hw/isa/isa.h"
  32 #include "hw/i386/pc.h"
  33
  34 #define TYPE_ISA_DEBUGCON_DEVICE "isa-debugcon"
  35 #define ISA_DEBUGCON_DEVICE(obj) \
  36      OBJECT_CHECK(ISADebugconState, (obj), TYPE_ISA_DEBUGCON_DEVICE)
  37
  38 //#define DEBUG_DEBUGCON
  39
  40 typedef struct DebugconState {
  41     MemoryRegion io;
  42     CharBackend chr;
  43     uint32_t readback;
  44 } DebugconState;
  45
  46 typedef struct ISADebugconState {
  47     ISADevice parent_obj;
  48
  49     uint32_t iobase;
  50     DebugconState state;
  51 } ISADebugconState;
  52
  53 static void debugcon_ioport_write(void *opaque, hwaddr addr, uint64_t val,
  54                                   unsigned width)
  55 {
  56     DebugconState *s = opaque;
  57     unsigned char ch = val;
  58
  59 #ifdef DEBUG_DEBUGCON
  60     printf(" [debugcon: write addr=0x%04" HWADDR_PRIx " val=0x%02" PRIx64 "]\n", addr, val);
  61 #endif
  62
  63     /* XXX this blocks entire thread. Rewrite to use
  64      * qemu_chr_fe_write and background I/O callbacks */
  65     qemu_chr_fe_write_all(&s->chr, &ch, 1);
  66 }
  67
  68
  69 static uint64_t debugcon_ioport_read(void *opaque, hwaddr addr, unsigned width)
  70 {
  71     DebugconState *s = opaque;
  72
  73 #ifdef DEBUG_DEBUGCON
  74     printf("debugcon: read addr=0x%04" HWADDR_PRIx "\n", addr);
  75 #endif
  76
  77     return s->readback;
  78 }
  79
  80 static const MemoryRegionOps debugcon_ops = {
  81     .read = debugcon_ioport_read,
  82     .write = debugcon_ioport_write,
  83     .valid.min_access_size = 1,
  84     .valid.max_access_size = 1,
  85     .endianness = DEVICE_LITTLE_ENDIAN,
  86 };
  87
  88 static void debugcon_realize_core(DebugconState *s, Error **errp)
  89 {
  90     if (!qemu_chr_fe_backend_connected(&s->chr)) {
  91         error_setg(errp, "Can't create debugcon device, empty char device");
  92         return;
  93     }
  94
  95     qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, NULL, NULL, s, NULL, true);
  96 }
  97
  98 static void debugcon_isa_realizefn(DeviceState *dev, Error **errp)
  99 {
 100     ISADevice *d = ISA_DEVICE(dev);
 101     ISADebugconState *isa = ISA_DEBUGCON_DEVICE(dev);
 102     DebugconState *s = &isa->state;
 103     Error *err = NULL;
 104
 105     debugcon_realize_core(s, &err);
 106     if (err != NULL) {
 107         error_propagate(errp, err);
 108         return;
 109     }
 110     memory_region_init_io(&s->io, OBJECT(dev), &debugcon_ops, s,
 111                           TYPE_ISA_DEBUGCON_DEVICE, 1);
 112     memory_region_add_subregion(isa_address_space_io(d),
 113                                 isa->iobase, &s->io);
 114 }
 115
 116 static Property debugcon_isa_properties[] = {
 117     DEFINE_PROP_UINT32("iobase", ISADebugconState, iobase, 0xe9),
 118     DEFINE_PROP_CHR("chardev",  ISADebugconState, state.chr),
 119     DEFINE_PROP_UINT32("readback", ISADebugconState, state.readback, 0xe9),
 120     DEFINE_PROP_END_OF_LIST(),
 121 };
 122
 123 static void debugcon_isa_class_initfn(ObjectClass *klass, void *data)
 124 {
 125     DeviceClass *dc = DEVICE_CLASS(klass);
 126
 127     dc->realize = debugcon_isa_realizefn;
 128     dc->props = debugcon_isa_properties;
 129     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 130 }
 131
 132 static const TypeInfo debugcon_isa_info = {
 133     .name          = TYPE_ISA_DEBUGCON_DEVICE,
 134     .parent        = TYPE_ISA_DEVICE,
 135     .instance_size = sizeof(ISADebugconState),
 136     .class_init    = debugcon_isa_class_initfn,
 137 };
 138
 139 static void debugcon_register_types(void)
 140 {
 141     type_register_static(&debugcon_isa_info);
 142 }
 143
 144 type_init(debugcon_register_types)