qemu/hw/char/debugcon.c
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   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 "qemu/module.h"
  30#include "chardev/char-fe.h"
  31#include "hw/isa/isa.h"
  32#include "hw/qdev-properties.h"
  33#include "hw/qdev-properties-system.h"
  34#include "qom/object.h"
  35
  36#define TYPE_ISA_DEBUGCON_DEVICE "isa-debugcon"
  37OBJECT_DECLARE_SIMPLE_TYPE(ISADebugconState, ISA_DEBUGCON_DEVICE)
  38
  39//#define DEBUG_DEBUGCON
  40
  41typedef struct DebugconState {
  42    MemoryRegion io;
  43    CharBackend chr;
  44    uint32_t readback;
  45} DebugconState;
  46
  47struct ISADebugconState {
  48    ISADevice parent_obj;
  49
  50    uint32_t iobase;
  51    DebugconState state;
  52};
  53
  54static void debugcon_ioport_write(void *opaque, hwaddr addr, uint64_t val,
  55                                  unsigned width)
  56{
  57    DebugconState *s = opaque;
  58    unsigned char ch = val;
  59
  60#ifdef DEBUG_DEBUGCON
  61    printf(" [debugcon: write addr=0x%04" HWADDR_PRIx " val=0x%02" PRIx64 "]\n", addr, val);
  62#endif
  63
  64    /* XXX this blocks entire thread. Rewrite to use
  65     * qemu_chr_fe_write and background I/O callbacks */
  66    qemu_chr_fe_write_all(&s->chr, &ch, 1);
  67}
  68
  69
  70static uint64_t debugcon_ioport_read(void *opaque, hwaddr addr, unsigned width)
  71{
  72    DebugconState *s = opaque;
  73
  74#ifdef DEBUG_DEBUGCON
  75    printf("debugcon: read addr=0x%04" HWADDR_PRIx "\n", addr);
  76#endif
  77
  78    return s->readback;
  79}
  80
  81static const MemoryRegionOps debugcon_ops = {
  82    .read = debugcon_ioport_read,
  83    .write = debugcon_ioport_write,
  84    .valid.min_access_size = 1,
  85    .valid.max_access_size = 1,
  86    .endianness = DEVICE_LITTLE_ENDIAN,
  87};
  88
  89static void debugcon_realize_core(DebugconState *s, Error **errp)
  90{
  91    if (!qemu_chr_fe_backend_connected(&s->chr)) {
  92        error_setg(errp, "Can't create debugcon device, empty char device");
  93        return;
  94    }
  95
  96    qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, NULL, NULL, s, NULL, true);
  97}
  98
  99static void debugcon_isa_realizefn(DeviceState *dev, Error **errp)
 100{
 101    ISADevice *d = ISA_DEVICE(dev);
 102    ISADebugconState *isa = ISA_DEBUGCON_DEVICE(dev);
 103    DebugconState *s = &isa->state;
 104    Error *err = NULL;
 105
 106    debugcon_realize_core(s, &err);
 107    if (err != NULL) {
 108        error_propagate(errp, err);
 109        return;
 110    }
 111    memory_region_init_io(&s->io, OBJECT(dev), &debugcon_ops, s,
 112                          TYPE_ISA_DEBUGCON_DEVICE, 1);
 113    memory_region_add_subregion(isa_address_space_io(d),
 114                                isa->iobase, &s->io);
 115}
 116
 117static Property debugcon_isa_properties[] = {
 118    DEFINE_PROP_UINT32("iobase", ISADebugconState, iobase, 0xe9),
 119    DEFINE_PROP_CHR("chardev",  ISADebugconState, state.chr),
 120    DEFINE_PROP_UINT32("readback", ISADebugconState, state.readback, 0xe9),
 121    DEFINE_PROP_END_OF_LIST(),
 122};
 123
 124static void debugcon_isa_class_initfn(ObjectClass *klass, void *data)
 125{
 126    DeviceClass *dc = DEVICE_CLASS(klass);
 127
 128    dc->realize = debugcon_isa_realizefn;
 129    device_class_set_props(dc, debugcon_isa_properties);
 130    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 131}
 132
 133static const TypeInfo debugcon_isa_info = {
 134    .name          = TYPE_ISA_DEBUGCON_DEVICE,
 135    .parent        = TYPE_ISA_DEVICE,
 136    .instance_size = sizeof(ISADebugconState),
 137    .class_init    = debugcon_isa_class_initfn,
 138};
 139
 140static void debugcon_register_types(void)
 141{
 142    type_register_static(&debugcon_isa_info);
 143}
 144
 145type_init(debugcon_register_types)
 146