hw/i386/vmport.c

   1 /*
   2  * QEMU VMPort emulation
   3  *
   4  * Copyright (C) 2007 Hervé Poussineau
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "qemu/osdep.h"
  25 #include "hw/isa/isa.h"
  26 #include "sysemu/hw_accel.h"
  27 #include "qemu/log.h"
  28 #include "vmport.h"
  29 #include "cpu.h"
  30 #include "trace.h"
  31
  32 #define VMPORT_CMD_GETVERSION 0x0a
  33 #define VMPORT_CMD_GETRAMSIZE 0x14
  34
  35 #define VMPORT_ENTRIES 0x2c
  36 #define VMPORT_MAGIC   0x564D5868
  37
  38 #define VMPORT(obj) OBJECT_CHECK(VMPortState, (obj), TYPE_VMPORT)
  39
  40 typedef struct VMPortState {
  41     ISADevice parent_obj;
  42
  43     MemoryRegion io;
  44     VMPortReadFunc *func[VMPORT_ENTRIES];
  45     void *opaque[VMPORT_ENTRIES];
  46 } VMPortState;
  47
  48 static VMPortState *port_state;
  49
  50 void vmport_register(unsigned char command, VMPortReadFunc *func, void *opaque)
  51 {
  52     if (command >= VMPORT_ENTRIES) {
  53         return;
  54     }
  55
  56     trace_vmport_register(command, func, opaque);
  57     port_state->func[command] = func;
  58     port_state->opaque[command] = opaque;
  59 }
  60
  61 static uint64_t vmport_ioport_read(void *opaque, hwaddr addr,
  62                                    unsigned size)
  63 {
  64     VMPortState *s = opaque;
  65     CPUState *cs = current_cpu;
  66     X86CPU *cpu = X86_CPU(cs);
  67     CPUX86State *env = &cpu->env;
  68     unsigned char command;
  69     uint32_t eax;
  70
  71     cpu_synchronize_state(cs);
  72
  73     eax = env->regs[R_EAX];
  74     if (eax != VMPORT_MAGIC) {
  75         return eax;
  76     }
  77
  78     command = env->regs[R_ECX];
  79     trace_vmport_command(command);
  80     if (command >= VMPORT_ENTRIES || !s->func[command]) {
  81         qemu_log_mask(LOG_UNIMP, "vmport: unknown command %x\n", command);
  82         return eax;
  83     }
  84
  85     return s->func[command](s->opaque[command], addr);
  86 }
  87
  88 static void vmport_ioport_write(void *opaque, hwaddr addr,
  89                                 uint64_t val, unsigned size)
  90 {
  91     X86CPU *cpu = X86_CPU(current_cpu);
  92
  93     cpu->env.regs[R_EAX] = vmport_ioport_read(opaque, addr, 4);
  94 }
  95
  96 static uint32_t vmport_cmd_get_version(void *opaque, uint32_t addr)
  97 {
  98     X86CPU *cpu = X86_CPU(current_cpu);
  99
 100     cpu->env.regs[R_EBX] = VMPORT_MAGIC;
 101     return 6;
 102 }
 103
 104 static uint32_t vmport_cmd_ram_size(void *opaque, uint32_t addr)
 105 {
 106     X86CPU *cpu = X86_CPU(current_cpu);
 107
 108     cpu->env.regs[R_EBX] = 0x1177;
 109     return ram_size;
 110 }
 111
 112 static const MemoryRegionOps vmport_ops = {
 113     .read = vmport_ioport_read,
 114     .write = vmport_ioport_write,
 115     .impl = {
 116         .min_access_size = 4,
 117         .max_access_size = 4,
 118     },
 119     .endianness = DEVICE_LITTLE_ENDIAN,
 120 };
 121
 122 static void vmport_realizefn(DeviceState *dev, Error **errp)
 123 {
 124     ISADevice *isadev = ISA_DEVICE(dev);
 125     VMPortState *s = VMPORT(dev);
 126
 127     memory_region_init_io(&s->io, OBJECT(s), &vmport_ops, s, "vmport", 1);
 128     isa_register_ioport(isadev, &s->io, 0x5658);
 129
 130     port_state = s;
 131     /* Register some generic port commands */
 132     vmport_register(VMPORT_CMD_GETVERSION, vmport_cmd_get_version, NULL);
 133     vmport_register(VMPORT_CMD_GETRAMSIZE, vmport_cmd_ram_size, NULL);
 134 }
 135
 136 static void vmport_class_initfn(ObjectClass *klass, void *data)
 137 {
 138     DeviceClass *dc = DEVICE_CLASS(klass);
 139
 140     dc->realize = vmport_realizefn;
 141     /* Reason: realize sets global port_state */
 142     dc->user_creatable = false;
 143 }
 144
 145 static const TypeInfo vmport_info = {
 146     .name          = TYPE_VMPORT,
 147     .parent        = TYPE_ISA_DEVICE,
 148     .instance_size = sizeof(VMPortState),
 149     .class_init    = vmport_class_initfn,
 150 };
 151
 152 static void vmport_register_types(void)
 153 {
 154     type_register_static(&vmport_info);
 155 }
 156
 157 type_init(vmport_register_types)