diff mbox

[v10,01/10] target-avr: AVR cores support is added.

Message ID 1467844395-28900-2-git-send-email-mrolnik@gmail.com
State New
Headers show

Commit Message

Michael Rolnik July 6, 2016, 10:33 p.m. UTC
1. basic CPU structure
    2. registers
    3. no instructions
    4. saving sreg, rampD, rampX, rampY, rampD, eind in HW representation saving cpu features

Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
---
 arch_init.c                     |   2 +
 configure                       |   5 +
 default-configs/avr-softmmu.mak |  21 +++
 include/disas/bfd.h             |   6 +
 include/sysemu/arch_init.h      |   1 +
 target-avr/Makefile.objs        |  23 +++
 target-avr/cpu-qom.h            |  84 +++++++++++
 target-avr/cpu.c                | 304 ++++++++++++++++++++++++++++++++++++++++
 target-avr/cpu.h                | 180 ++++++++++++++++++++++++
 target-avr/gdbstub.c            |  84 +++++++++++
 target-avr/helper.c             |  87 ++++++++++++
 target-avr/helper.h             |  21 +++
 target-avr/machine.c            | 116 +++++++++++++++
 target-avr/machine.h            |  21 +++
 target-avr/translate.c          | 291 ++++++++++++++++++++++++++++++++++++++
 15 files changed, 1246 insertions(+)
 create mode 100644 default-configs/avr-softmmu.mak
 create mode 100644 target-avr/Makefile.objs
 create mode 100644 target-avr/cpu-qom.h
 create mode 100644 target-avr/cpu.c
 create mode 100644 target-avr/cpu.h
 create mode 100644 target-avr/gdbstub.c
 create mode 100644 target-avr/helper.c
 create mode 100644 target-avr/helper.h
 create mode 100644 target-avr/machine.c
 create mode 100644 target-avr/machine.h
 create mode 100644 target-avr/translate.c

Comments

Richard Henderson July 12, 2016, 5:19 p.m. UTC | #1
On 07/06/2016 03:33 PM, Michael Rolnik wrote:
> +static bool avr_cpu_has_work(CPUState *cs)
> +{
> +    AVRCPU *cpu = AVR_CPU(cs);
> +    CPUAVRState *env = &cpu->env;
> +
> +    return      (cs->interrupt_request
> +                &   (CPU_INTERRUPT_HARD
> +                    | CPU_INTERRUPT_RESET))
> +            &&  cpu_interrupts_enabled(env);
> +}
> +static void avr_cpu_synchronize_from_tb(CPUState *cs, TranslationBlock *tb)
> +{
> +    AVRCPU      *cpu = AVR_CPU(cs);
> +    CPUAVRState *env = &cpu->env;
> +
> +    env->pc_w = tb->pc / 2;   /*  internally PC points to words   */
> +}

For the 4th time: missing spaces between functions.  Lots of them.  Please fix
them all, without me having to repeat myself a 5th time.

> +    bool            fullacc;/*  CPU/MEM if true MEM only otherwise  */

...

> +static inline void cpu_get_tb_cpu_state(CPUAVRState *env, target_ulong *pc,
> +                                target_ulong *cs_base, uint32_t *pflags)
> +{
> +    *pc = env->pc_w * 2;
> +    *cs_base = 0;
> +    *pflags = 0;
> +}

The fullacc bit needs to be reflected in *pflags here.  The way you are
accessing env->fullacc from translate*.c is invalid.


r~
Michael Rolnik July 13, 2016, 3:32 a.m. UTC | #2
Hi Richard,

Please explain why I am not accessing fullacc correctly.

On Tue, Jul 12, 2016 at 10:19 AM, Richard Henderson <rth@twiddle.net> wrote:

> On 07/06/2016 03:33 PM, Michael Rolnik wrote:
> > +static bool avr_cpu_has_work(CPUState *cs)
> > +{
> > +    AVRCPU *cpu = AVR_CPU(cs);
> > +    CPUAVRState *env = &cpu->env;
> > +
> > +    return      (cs->interrupt_request
> > +                &   (CPU_INTERRUPT_HARD
> > +                    | CPU_INTERRUPT_RESET))
> > +            &&  cpu_interrupts_enabled(env);
> > +}
> > +static void avr_cpu_synchronize_from_tb(CPUState *cs, TranslationBlock
> *tb)
> > +{
> > +    AVRCPU      *cpu = AVR_CPU(cs);
> > +    CPUAVRState *env = &cpu->env;
> > +
> > +    env->pc_w = tb->pc / 2;   /*  internally PC points to words   */
> > +}
>
> For the 4th time: missing spaces between functions.  Lots of them.  Please
> fix
> them all, without me having to repeat myself a 5th time.
>
> > +    bool            fullacc;/*  CPU/MEM if true MEM only otherwise  */
>
> ...
>
> > +static inline void cpu_get_tb_cpu_state(CPUAVRState *env, target_ulong
> *pc,
> > +                                target_ulong *cs_base, uint32_t *pflags)
> > +{
> > +    *pc = env->pc_w * 2;
> > +    *cs_base = 0;
> > +    *pflags = 0;
> > +}
>
> The fullacc bit needs to be reflected in *pflags here.  The way you are
> accessing env->fullacc from translate*.c is invalid.
>
>
> r~
>
>
Richard Henderson July 13, 2016, 7:17 a.m. UTC | #3
On 07/12/2016 08:32 PM, Michael Rolnik wrote:
> Hi Richard,
>
> Please explain why I am not accessing fullacc correctly.

You can't examine fields of env, which vary, during translate.c.
You must only examine fields of TB, which are invariant.


r~
Michael Rolnik July 13, 2016, 10:54 a.m. UTC | #4
So how do I get this flag unset?

On Wed, Jul 13, 2016, 12:17 AM Richard Henderson <rth@twiddle.net> wrote:

> On 07/12/2016 08:32 PM, Michael Rolnik wrote:
> > Hi Richard,
> >
> > Please explain why I am not accessing fullacc correctly.
>
> You can't examine fields of env, which vary, during translate.c.
> You must only examine fields of TB, which are invariant.
>
>
> r~
>
Michael Rolnik July 13, 2016, 12:35 p.m. UTC | #5
a. a helper function sets a flag within env
b. cpu_get_tb_cpu_state introduces this flag, though tb.flags, for code
generation by gen_intermediate_code
c. the code is generated
d. the flag remains to be set within env. Who clear it?

On Wed, Jul 13, 2016 at 3:54 AM, Michael Rolnik <mrolnik@gmail.com> wrote:

> So how do I get this flag unset?
>
> On Wed, Jul 13, 2016, 12:17 AM Richard Henderson <rth@twiddle.net> wrote:
>
>> On 07/12/2016 08:32 PM, Michael Rolnik wrote:
>> > Hi Richard,
>> >
>> > Please explain why I am not accessing fullacc correctly.
>>
>> You can't examine fields of env, which vary, during translate.c.
>> You must only examine fields of TB, which are invariant.
>>
>>
>> r~
>>
>
Richard Henderson July 13, 2016, 3:27 p.m. UTC | #6
On 07/13/2016 05:35 AM, Michael Rolnik wrote:
> a. a helper function sets a flag within env

... and exits the cpu loop.

> b. cpu_get_tb_cpu_state introduces this flag, though tb.flags, for code
> generation by gen_intermediate_code
> c. the code is generated 

Yep.

> d. the flag remains to be set within env. Who clear it?

Presumably this flag is only usefully set for one instruction, the one we've
just determined accesses the registers.  So I'd clear the flag within
helper_fullwr / helper_fullrd.

In translate.c, when you notice tb->flags & HF_FULLACC is set, you'd interpret
one instruction and then exit the TB.  That way we'll start the next TB with
HF_FULLACC cleared.

Thus for a series of instructions like

	insn1
	insn2
	insn3 (writes to register)
	insn4
	branch

we will generate 3 TB:

TB1: (flags = 0)
	insn1
	insn2
	insn3
	insn4
	branch

TB2: (flags = HF_FULLACC)
	insn3

TB3: (flags = 0)
	insn4
	branch

Most importantly, when we come to execute TB1 for the second time, we will find
TB2 and TB3 quickly, with the right set of flags.


r~
diff mbox

Patch

diff --git a/arch_init.c b/arch_init.c
index fa05973..be6e6de 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -80,6 +80,8 @@  int graphic_depth = 32;
 #define QEMU_ARCH QEMU_ARCH_UNICORE32
 #elif defined(TARGET_TRICORE)
 #define QEMU_ARCH QEMU_ARCH_TRICORE
+#elif defined(TARGET_AVR)
+#define QEMU_ARCH QEMU_ARCH_AVR
 #endif
 
 const uint32_t arch_type = QEMU_ARCH;
diff --git a/configure b/configure
index e9090a0..29eafbb 100755
--- a/configure
+++ b/configure
@@ -5641,6 +5641,8 @@  case "$target_name" in
   x86_64)
     TARGET_BASE_ARCH=i386
   ;;
+  avr)
+  ;;
   alpha)
   ;;
   arm|armeb)
@@ -5837,6 +5839,9 @@  disas_config() {
 
 for i in $ARCH $TARGET_BASE_ARCH ; do
   case "$i" in
+  avr)
+    disas_config "AVR"
+  ;;
   alpha)
     disas_config "ALPHA"
   ;;
diff --git a/default-configs/avr-softmmu.mak b/default-configs/avr-softmmu.mak
new file mode 100644
index 0000000..003465d
--- /dev/null
+++ b/default-configs/avr-softmmu.mak
@@ -0,0 +1,21 @@ 
+#
+#  QEMU AVR CPU
+#
+#  Copyright (c) 2016 Michael Rolnik
+#
+#  This library is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU Lesser General Public
+#  License as published by the Free Software Foundation; either
+#  version 2.1 of the License, or (at your option) any later version.
+#
+#  This library is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+#  Lesser General Public License for more details.
+#
+#  You should have received a copy of the GNU Lesser General Public
+#  License along with this library; if not, see
+#  <http://www.gnu.org/licenses/lgpl-2.1.html>
+#
+
+# Default configuration for avr-softmmu
diff --git a/include/disas/bfd.h b/include/disas/bfd.h
index a112e9c..b13fc53 100644
--- a/include/disas/bfd.h
+++ b/include/disas/bfd.h
@@ -213,6 +213,12 @@  enum bfd_architecture
 #define bfd_mach_m32r          0  /* backwards compatibility */
   bfd_arch_mn10200,    /* Matsushita MN10200 */
   bfd_arch_mn10300,    /* Matsushita MN10300 */
+  bfd_arch_avr,       /* Atmel AVR microcontrollers.  */
+#define bfd_mach_avr1          1
+#define bfd_mach_avr2          2
+#define bfd_mach_avr3          3
+#define bfd_mach_avr4          4
+#define bfd_mach_avr5          5
   bfd_arch_cris,       /* Axis CRIS */
 #define bfd_mach_cris_v0_v10   255
 #define bfd_mach_cris_v32      32
diff --git a/include/sysemu/arch_init.h b/include/sysemu/arch_init.h
index d690dfa..8c75777 100644
--- a/include/sysemu/arch_init.h
+++ b/include/sysemu/arch_init.h
@@ -23,6 +23,7 @@  enum {
     QEMU_ARCH_UNICORE32 = (1 << 14),
     QEMU_ARCH_MOXIE = (1 << 15),
     QEMU_ARCH_TRICORE = (1 << 16),
+    QEMU_ARCH_AVR = (1 << 17),
 };
 
 extern const uint32_t arch_type;
diff --git a/target-avr/Makefile.objs b/target-avr/Makefile.objs
new file mode 100644
index 0000000..2a10104
--- /dev/null
+++ b/target-avr/Makefile.objs
@@ -0,0 +1,23 @@ 
+#
+#  QEMU AVR CPU
+#
+#  Copyright (c) 2016 Michael Rolnik
+#
+#  This library is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU Lesser General Public
+#  License as published by the Free Software Foundation; either
+#  version 2.1 of the License, or (at your option) any later version.
+#
+#  This library is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+#  Lesser General Public License for more details.
+#
+#  You should have received a copy of the GNU Lesser General Public
+#  License along with this library; if not, see
+#  <http://www.gnu.org/licenses/lgpl-2.1.html>
+#
+
+obj-y   += translate.o cpu.o helper.o
+obj-y   += gdbstub.o
+obj-$(CONFIG_SOFTMMU) += machine.o
diff --git a/target-avr/cpu-qom.h b/target-avr/cpu-qom.h
new file mode 100644
index 0000000..c5d4f92
--- /dev/null
+++ b/target-avr/cpu-qom.h
@@ -0,0 +1,84 @@ 
+/*
+ * QEMU AVR CPU
+ *
+ * Copyright (c) 2016 Michael Rolnik
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/lgpl-2.1.html>
+ */
+
+#ifndef QEMU_AVR_CPU_QOM_H
+#define QEMU_AVR_CPU_QOM_H
+
+#include "qom/cpu.h"
+
+#define TYPE_AVR_CPU            "avr"
+
+#define AVR_CPU_CLASS(klass)    \
+                    OBJECT_CLASS_CHECK(AVRCPUClass, (klass), TYPE_AVR_CPU)
+#define AVR_CPU(obj)            \
+                    OBJECT_CHECK(AVRCPU, (obj), TYPE_AVR_CPU)
+#define AVR_CPU_GET_CLASS(obj)  \
+                    OBJECT_GET_CLASS(AVRCPUClass, (obj), TYPE_AVR_CPU)
+
+/**
+*  AVRCPUClass:
+*  @parent_realize: The parent class' realize handler.
+*  @parent_reset: The parent class' reset handler.
+*  @vr: Version Register value.
+*
+*  A AVR CPU model.
+*/
+typedef struct AVRCPUClass {
+    CPUClass        parent_class;
+
+    DeviceRealize   parent_realize;
+    void (*parent_reset)(CPUState *cpu);
+} AVRCPUClass;
+
+/**
+*  AVRCPU:
+*  @env: #CPUAVRState
+*
+*  A AVR CPU.
+*/
+typedef struct AVRCPU {
+    /*< private >*/
+    CPUState        parent_obj;
+    /*< public >*/
+
+    CPUAVRState     env;
+} AVRCPU;
+
+static inline AVRCPU   *avr_env_get_cpu(CPUAVRState *env)
+{
+    return container_of(env, AVRCPU, env);
+}
+
+#define ENV_GET_CPU(e)          CPU(avr_env_get_cpu(e))
+#define ENV_OFFSET              offsetof(AVRCPU, env)
+
+#ifndef CONFIG_USER_ONLY
+extern const struct VMStateDescription vms_avr_cpu;
+#endif
+
+void avr_cpu_do_interrupt(CPUState *cpu);
+bool avr_cpu_exec_interrupt(CPUState *cpu, int int_req);
+void avr_cpu_dump_state(CPUState *cs, FILE *f,
+                            fprintf_function cpu_fprintf, int flags);
+hwaddr avr_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
+int avr_cpu_gdb_read_register(CPUState *cpu, uint8_t *buf, int reg);
+int avr_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
+
+#endif
diff --git a/target-avr/cpu.c b/target-avr/cpu.c
new file mode 100644
index 0000000..1fdc1e6
--- /dev/null
+++ b/target-avr/cpu.c
@@ -0,0 +1,304 @@ 
+/*
+ * QEMU AVR CPU
+ *
+ * Copyright (c) 2016 Michael Rolnik
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/lgpl-2.1.html>
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "cpu.h"
+#include "qemu-common.h"
+#include "migration/vmstate.h"
+#include "machine.h"
+
+static void avr_cpu_set_pc(CPUState *cs, vaddr value)
+{
+    AVRCPU   *cpu = AVR_CPU(cs);
+
+    cpu->env.pc_w = value / 2;    /*  internally PC points to words   */
+}
+
+static bool avr_cpu_has_work(CPUState *cs)
+{
+    AVRCPU *cpu = AVR_CPU(cs);
+    CPUAVRState *env = &cpu->env;
+
+    return      (cs->interrupt_request
+                &   (CPU_INTERRUPT_HARD
+                    | CPU_INTERRUPT_RESET))
+            &&  cpu_interrupts_enabled(env);
+}
+static void avr_cpu_synchronize_from_tb(CPUState *cs, TranslationBlock *tb)
+{
+    AVRCPU      *cpu = AVR_CPU(cs);
+    CPUAVRState *env = &cpu->env;
+
+    env->pc_w = tb->pc / 2;   /*  internally PC points to words   */
+}
+
+static void avr_cpu_reset(CPUState *s)
+{
+    AVRCPU *cpu = AVR_CPU(s);
+    AVRCPUClass *mcc = AVR_CPU_GET_CLASS(cpu);
+    CPUAVRState *env = &cpu->env;
+
+    mcc->parent_reset(s);
+
+    env->pc_w = 0;
+    env->sregI = 1;
+    env->sregC = 0;
+    env->sregZ = 0;
+    env->sregN = 0;
+    env->sregV = 0;
+    env->sregS = 0;
+    env->sregH = 0;
+    env->sregT = 0;
+
+    env->rampD = 0;
+    env->rampX = 0;
+    env->rampY = 0;
+    env->rampZ = 0;
+    env->eind = 0;
+    env->sp = 0;
+
+    memset(env->io, 0, sizeof(env->io));
+    memset(env->r, 0, sizeof(env->r));
+
+    tlb_flush(s, 1);
+}
+
+static void avr_cpu_disas_set_info(CPUState *cpu, disassemble_info *info)
+{
+    info->mach = bfd_arch_avr;
+    info->print_insn = NULL;
+}
+
+static void avr_cpu_realizefn(DeviceState *dev, Error **errp)
+{
+    CPUState *cs = CPU(dev);
+    AVRCPUClass *mcc = AVR_CPU_GET_CLASS(dev);
+
+    qemu_init_vcpu(cs);
+    cpu_reset(cs);
+
+    mcc->parent_realize(dev, errp);
+}
+
+static void avr_cpu_set_int(void *opaque, int irq, int level)
+{
+    AVRCPU *cpu = opaque;
+    CPUAVRState *env = &cpu->env;
+    CPUState *cs = CPU(cpu);
+
+    uint64_t mask = (1ull << irq);
+    if (level) {
+        env->intsrc |=  mask;
+        cpu_interrupt(cs, CPU_INTERRUPT_HARD);
+    } else {
+        env->intsrc &= ~mask;
+        if (env->intsrc == 0) {
+            cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
+        }
+    }
+}
+
+static void avr_cpu_initfn(Object *obj)
+{
+    CPUState *cs = CPU(obj);
+    AVRCPU *cpu = AVR_CPU(obj);
+    static int inited;
+
+    cs->env_ptr = &cpu->env;
+    cpu_exec_init(cs, &error_abort);
+
+#ifndef CONFIG_USER_ONLY
+    qdev_init_gpio_in(DEVICE(cpu), avr_cpu_set_int, 37);
+#endif
+
+    if (tcg_enabled() && !inited) {
+        inited = 1;
+        avr_translate_init();
+    }
+}
+
+static ObjectClass *avr_cpu_class_by_name(const char *cpu_model)
+{
+    ObjectClass *oc;
+    char *typename;
+    char **cpuname;
+
+    if (!cpu_model) {
+        return NULL;
+    }
+
+    cpuname = g_strsplit(cpu_model, ",", 1);
+    typename = g_strdup_printf("%s-" TYPE_AVR_CPU, cpuname[0]);
+    oc = object_class_by_name(typename);
+
+    g_strfreev(cpuname);
+    g_free(typename);
+
+    if (!oc
+        ||  !object_class_dynamic_cast(oc, TYPE_AVR_CPU)
+        ||  object_class_is_abstract(oc)) {
+        return NULL;
+    }
+
+    return oc;
+}
+
+static void avr_cpu_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+    CPUClass *cc = CPU_CLASS(oc);
+    AVRCPUClass *mcc = AVR_CPU_CLASS(oc);
+
+    mcc->parent_realize = dc->realize;
+    dc->realize = avr_cpu_realizefn;
+
+    mcc->parent_reset = cc->reset;
+    cc->reset = avr_cpu_reset;
+
+    cc->class_by_name = avr_cpu_class_by_name;
+
+    cc->has_work = avr_cpu_has_work;
+    cc->do_interrupt = avr_cpu_do_interrupt;
+    cc->cpu_exec_interrupt = avr_cpu_exec_interrupt;
+    cc->dump_state = avr_cpu_dump_state;
+    cc->set_pc = avr_cpu_set_pc;
+#if !defined(CONFIG_USER_ONLY)
+    cc->memory_rw_debug = avr_cpu_memory_rw_debug;
+#endif
+#ifdef CONFIG_USER_ONLY
+    cc->handle_mmu_fault = avr_cpu_handle_mmu_fault;
+#else
+    cc->get_phys_page_debug = avr_cpu_get_phys_page_debug;
+    cc->vmsd = &vms_avr_cpu;
+#endif
+    cc->disas_set_info = avr_cpu_disas_set_info;
+    cc->synchronize_from_tb = avr_cpu_synchronize_from_tb;
+    cc->gdb_read_register = avr_cpu_gdb_read_register;
+    cc->gdb_write_register = avr_cpu_gdb_write_register;
+    cc->gdb_num_core_regs = 35;
+
+    /*
+     * Reason: avr_cpu_initfn() calls cpu_exec_init(), which saves
+     * the object in cpus -> dangling pointer after final
+     * object_unref().
+     */
+    dc->cannot_destroy_with_object_finalize_yet = true;
+}
+
+static void avr_any_initfn(Object *obj)
+{
+    /* Set cpu feature flags */
+}
+
+typedef struct AVRCPUInfo {
+    const char     *name;
+    void (*initfn)(Object *obj);
+} AVRCPUInfo;
+
+static const AVRCPUInfo avr_cpus[] = {
+    {   .name = "any",      .initfn = avr_any_initfn },
+};
+
+static gint avr_cpu_list_compare(gconstpointer a, gconstpointer b)
+{
+    ObjectClass *class_a = (ObjectClass *)a;
+    ObjectClass *class_b = (ObjectClass *)b;
+    const char *name_a;
+    const char *name_b;
+
+    name_a = object_class_get_name(class_a);
+    name_b = object_class_get_name(class_b);
+    if (strcmp(name_a, "any-" TYPE_AVR_CPU) == 0) {
+        return 1;
+    } else if (strcmp(name_b, "any-" TYPE_AVR_CPU) == 0) {
+        return -1;
+    } else {
+        return strcmp(name_a, name_b);
+    }
+}
+
+static void avr_cpu_list_entry(gpointer data, gpointer user_data)
+{
+    ObjectClass *oc = data;
+    CPUListState *s = user_data;
+    const char *typename;
+    char *name;
+
+    typename = object_class_get_name(oc);
+    name = g_strndup(typename, strlen(typename) - strlen("-" TYPE_AVR_CPU));
+    (*s->cpu_fprintf)(s->file, "  %s\n", name);
+    g_free(name);
+}
+
+void avr_cpu_list(FILE *f, fprintf_function cpu_fprintf)
+{
+    CPUListState s = {
+        .file = f,
+        .cpu_fprintf = cpu_fprintf,
+    };
+    GSList *list;
+
+    list = object_class_get_list(TYPE_AVR_CPU, false);
+    list = g_slist_sort(list, avr_cpu_list_compare);
+    (*cpu_fprintf)(f, "Available CPUs:\n");
+    g_slist_foreach(list, avr_cpu_list_entry, &s);
+    g_slist_free(list);
+}
+AVRCPU *cpu_avr_init(const char *cpu_model)
+{
+    return AVR_CPU(cpu_generic_init(TYPE_AVR_CPU, cpu_model));
+}
+
+static void cpu_register(const AVRCPUInfo *info)
+{
+    TypeInfo type_info = {
+        .parent = TYPE_AVR_CPU,
+        .instance_size = sizeof(AVRCPU),
+        .instance_init = info->initfn,
+        .class_size = sizeof(AVRCPUClass),
+    };
+
+    type_info.name = g_strdup_printf("%s-" TYPE_AVR_CPU, info->name);
+    type_register(&type_info);
+    g_free((void *)type_info.name);
+}
+
+static const TypeInfo avr_cpu_type_info = {
+    .name = TYPE_AVR_CPU,
+    .parent = TYPE_CPU,
+    .instance_size = sizeof(AVRCPU),
+    .instance_init = avr_cpu_initfn,
+    .class_size = sizeof(AVRCPUClass),
+    .class_init = avr_cpu_class_init,
+    .abstract = true,
+};
+
+static void avr_cpu_register_types(void)
+{
+    int i;
+    type_register_static(&avr_cpu_type_info);
+
+    for (i = 0; i < ARRAY_SIZE(avr_cpus); i++) {
+        cpu_register(&avr_cpus[i]);
+    }
+}
+
+type_init(avr_cpu_register_types)
diff --git a/target-avr/cpu.h b/target-avr/cpu.h
new file mode 100644
index 0000000..74bbd8c
--- /dev/null
+++ b/target-avr/cpu.h
@@ -0,0 +1,180 @@ 
+ /*
+ * QEMU AVR CPU
+ *
+ * Copyright (c) 2016 Michael Rolnik
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/lgpl-2.1.html>
+ */
+
+#if !defined(CPU_AVR_H)
+#define CPU_AVR_H
+
+#include "qemu-common.h"
+
+#define TARGET_LONG_BITS            32
+
+#define CPUArchState struct CPUAVRState
+
+#include "exec/cpu-defs.h"
+#include "fpu/softfloat.h"
+
+/*
+    TARGET_PAGE_BITS cannot be more than 8 bits because
+    1.  all IO registers occupy [0x0000 .. 0x00ff] address range, and they
+        should be implemented as a device and not memory
+    2.  SRAM starts at the address 0x0100
+*/
+#define TARGET_PAGE_BITS            8
+#define TARGET_PHYS_ADDR_SPACE_BITS 24
+#define TARGET_VIRT_ADDR_SPACE_BITS 24
+#define NB_MMU_MODES                2
+
+#define MMU_CODE_IDX                0
+#define MMU_DATA_IDX                1
+
+#define EXCP_RESET                  1
+#define EXCP_INT(n)                 (EXCP_RESET + (n) + 1)
+
+#define PHYS_ADDR_MASK              0xfff00000
+
+#define PHYS_BASE_CODE              0x00000000
+#define PHYS_BASE_DATA              0x00800000
+#define PHYS_BASE_REGS              0x10000000
+
+#define VIRT_BASE_CODE              0x00000000
+#define VIRT_BASE_DATA              0x00000000
+#define VIRT_BASE_REGS              0x00000000
+
+/*
+    there are three groups of registers
+    1. CPU regs     - accessable by LD/ST and CPU itself
+    2. CPU IO regs  - accessable by LD/ST and IN/OUT
+    3. EXT IO regs  - accessable by LD/ST
+*/
+#define AVR_CPU_REGS                0x0020
+#define AVR_CPU_IO_REGS             0x0040
+#define AVR_EXT_IO_REGS             0x00a0
+#define AVR_IO_REGS                 (AVR_CPU_IO_REGS + AVR_EXT_IO_REGS)
+#define AVR_REGS                    (AVR_IO_REGS + AVR_CPU_REGS)
+
+#define AVR_CPU_REGS_BASE           0x0000
+#define AVR_CPU_IO_REGS_BASE        (AVR_CPU_REGS_BASE + AVR_CPU_REGS)
+#define AVR_EXT_IO_REGS_BASE        (AVR_CPU_IO_REGS_BASE + AVR_CPU_IO_REGS)
+
+#define AVR_CPU_REGS_LAST           (AVR_CPU_REGS_BASE + AVR_CPU_REGS - 1)
+#define AVR_CPU_IO_REGS_LAST        (AVR_CPU_IO_REGS_BASE + AVR_CPU_IO_REGS - 1)
+#define AVR_EXT_IO_REGS_LAST        (AVR_EXT_IO_REGS_BASE + AVR_EXT_IO_REGS - 1)
+
+typedef struct CPUAVRState CPUAVRState;
+
+struct CPUAVRState {
+    uint32_t        pc_w;   /*   0x003fffff up to 22 bits           */
+
+    uint32_t        sregC;  /*   0x00000001 1 bits                  */
+    uint32_t        sregZ;  /*   0x0000ffff 16 bits, negative logic */
+    uint32_t        sregN;  /*   0x00000001 1 bits                  */
+    uint32_t        sregV;  /*   0x00000001 1 bits                  */
+    uint32_t        sregS;  /*   0x00000001 1 bits                  */
+    uint32_t        sregH;  /*   0x00000001 1 bits                  */
+    uint32_t        sregT;  /*   0x00000001 1 bits                  */
+    uint32_t        sregI;  /*   0x00000001 1 bits                  */
+
+    uint32_t        rampD;  /*   0x00ff0000 8 bits                  */
+    uint32_t        rampX;  /*   0x00ff0000 8 bits                  */
+    uint32_t        rampY;  /*   0x00ff0000 8 bits                  */
+    uint32_t        rampZ;  /*   0x00ff0000 8 bits                  */
+    uint32_t        eind;   /*   0x00ff0000 8 bits                  */
+
+    uint32_t        io[AVR_CPU_IO_REGS];
+                            /*   8 bits each                        */
+    uint32_t        r[AVR_CPU_REGS];
+                            /*   8 bits each                        */
+    uint32_t        sp;     /*   16 bits                            */
+
+
+    uint64_t        intsrc; /*  interrupt sources                   */
+
+    bool            fullacc;/*  CPU/MEM if true MEM only otherwise  */
+    /* Those resources are used only in QEMU core */
+    CPU_COMMON
+};
+
+#define cpu_list            avr_cpu_list
+#define cpu_signal_handler  cpu_avr_signal_handler
+
+#include "exec/cpu-all.h"
+#include "cpu-qom.h"
+
+static inline int cpu_mmu_index(CPUAVRState *env, bool ifetch)
+{
+    return  ifetch ? MMU_CODE_IDX : MMU_DATA_IDX;
+}
+
+void avr_translate_init(void);
+
+AVRCPU *cpu_avr_init(const char *cpu_model);
+
+#define cpu_init(cpu_model) CPU(cpu_avr_init(cpu_model))
+
+void avr_cpu_list(FILE *f, fprintf_function cpu_fprintf);
+int cpu_avr_exec(CPUState *cpu);
+int cpu_avr_signal_handler(int host_signum, void *pinfo, void *puc);
+int avr_cpu_handle_mmu_fault(CPUState *cpu, vaddr address, int rw,
+                                int mmu_idx);
+int avr_cpu_memory_rw_debug(CPUState *cs, vaddr address, uint8_t *buf,
+                                int len, bool is_write);
+
+static inline void cpu_get_tb_cpu_state(CPUAVRState *env, target_ulong *pc,
+                                target_ulong *cs_base, uint32_t *pflags)
+{
+    *pc = env->pc_w * 2;
+    *cs_base = 0;
+    *pflags = 0;
+}
+
+static inline int cpu_interrupts_enabled(CPUAVRState *env1)
+{
+    return  env1->sregI != 0;
+}
+
+static inline uint8_t cpu_get_sreg(CPUAVRState *env)
+{
+    uint8_t sreg;
+    sreg = (env->sregC & 0x01) << 0
+            | (env->sregZ == 0 ? 1 : 0) << 1
+            | (env->sregN) << 2
+            | (env->sregV) << 3
+            | (env->sregS) << 4
+            | (env->sregH) << 5
+            | (env->sregT) << 6
+            | (env->sregI) << 7;
+    return  sreg;
+}
+
+static inline void cpu_set_sreg(CPUAVRState *env, uint8_t sreg)
+{
+    env->sregC = (sreg >> 0) & 0x01;
+    env->sregZ = (sreg >> 1) & 0x01 ? 0 : 1;
+    env->sregN = (sreg >> 2) & 0x01;
+    env->sregV = (sreg >> 3) & 0x01;
+    env->sregS = (sreg >> 4) & 0x01;
+    env->sregH = (sreg >> 5) & 0x01;
+    env->sregT = (sreg >> 6) & 0x01;
+    env->sregI = (sreg >> 7) & 0x01;
+}
+
+#include "exec/exec-all.h"
+
+#endif /* !defined (CPU_AVR_H) */
diff --git a/target-avr/gdbstub.c b/target-avr/gdbstub.c
new file mode 100644
index 0000000..a53ba09
--- /dev/null
+++ b/target-avr/gdbstub.c
@@ -0,0 +1,84 @@ 
+/*
+ * QEMU AVR CPU
+ *
+ * Copyright (c) 2016 Michael Rolnik
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/lgpl-2.1.html>
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "exec/gdbstub.h"
+
+int avr_cpu_gdb_read_register(CPUState *cs, uint8_t *mem_buf, int n)
+{
+    AVRCPU *cpu = AVR_CPU(cs);
+    CPUAVRState *env = &cpu->env;
+
+    /*  R */
+    if (n < 32) {
+        return gdb_get_reg8(mem_buf, env->r[n]);
+    }
+
+    /*  SREG */
+    if (n == 32) {
+        uint8_t sreg = cpu_get_sreg(env);
+
+        return gdb_get_reg8(mem_buf, sreg);
+    }
+
+    /*  SP */
+    if (n == 33) {
+        return  gdb_get_reg16(mem_buf, env->sp & 0x0000ffff);
+    }
+
+    /*  PC */
+    if (n == 34) {
+        return  gdb_get_reg32(mem_buf, env->pc_w * 2);
+    }
+
+    return 0;
+}
+
+int avr_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
+{
+    AVRCPU *cpu = AVR_CPU(cs);
+    CPUAVRState *env = &cpu->env;
+    uint16_t tmp = ldl_p(mem_buf);
+
+    /*  R */
+    if (n < 32) {
+        env->r[n] = tmp;
+    }
+
+    /*  SREG */
+    if (n == 32) {
+        cpu_set_sreg(env, tmp);
+    }
+
+    /*  SP */
+    if (n == 33) {
+        env->sp = tmp;
+        return  2;
+    }
+
+    /*  PC */
+    if (n == 34) {
+        env->pc_w = tmp / 2;
+        return  4;
+    }
+
+    return 1;
+}
diff --git a/target-avr/helper.c b/target-avr/helper.c
new file mode 100644
index 0000000..3e23646
--- /dev/null
+++ b/target-avr/helper.c
@@ -0,0 +1,87 @@ 
+/*
+ * QEMU AVR CPU
+ *
+ * Copyright (c) 2016 Michael Rolnik
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/lgpl-2.1.html>
+ */
+
+#include "qemu/osdep.h"
+
+#include "cpu.h"
+#include "hw/irq.h"
+#include "include/hw/sysbus.h"
+#include "include/sysemu/sysemu.h"
+#include "exec/exec-all.h"
+#include "exec/cpu_ldst.h"
+#include "qemu/host-utils.h"
+#include "exec/helper-proto.h"
+
+bool avr_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
+{
+    return  false;
+}
+
+void avr_cpu_do_interrupt(CPUState *cs)
+{
+}
+
+int avr_cpu_memory_rw_debug(CPUState *cs, vaddr addr, uint8_t *buf,
+                                int len, bool is_write)
+{
+    return  cpu_memory_rw_debug(cs, addr, buf, len, is_write);
+}
+
+hwaddr avr_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
+{
+    return  addr;   /*  I assume 1:1 address correspondance */
+}
+
+int avr_cpu_handle_mmu_fault(CPUState *cs, vaddr address, int rw, int mmu_idx)
+{
+    cs->exception_index = EXCP_DEBUG;
+    cpu_dump_state(cs, stderr, fprintf, 0);
+    return 1;
+}
+
+void tlb_fill(CPUState *cs, target_ulong vaddr, int is_write,
+                                int mmu_idx, uintptr_t retaddr)
+{
+    target_ulong page_size = TARGET_PAGE_SIZE;
+    int prot = 0;
+    MemTxAttrs attrs = {};
+    uint32_t paddr;
+
+    vaddr &= TARGET_PAGE_MASK;
+
+    if (mmu_idx == MMU_CODE_IDX) {
+        paddr = PHYS_BASE_CODE + vaddr;
+        prot = PAGE_READ | PAGE_EXEC;
+    } else {
+        paddr = PHYS_BASE_DATA + vaddr;
+        prot = PAGE_READ | PAGE_WRITE;
+    }
+
+    tlb_set_page_with_attrs(cs, vaddr, paddr, attrs, prot, mmu_idx, page_size);
+}
+
+void helper_debug(CPUAVRState *env)
+{
+    CPUState *cs = CPU(avr_env_get_cpu(env));
+
+    cs->exception_index = EXCP_DEBUG;
+    cpu_loop_exit(cs);
+}
+
diff --git a/target-avr/helper.h b/target-avr/helper.h
new file mode 100644
index 0000000..b5ef3bf
--- /dev/null
+++ b/target-avr/helper.h
@@ -0,0 +1,21 @@ 
+/*
+ * QEMU AVR CPU
+ *
+ * Copyright (c) 2016 Michael Rolnik
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/lgpl-2.1.html>
+ */
+
+DEF_HELPER_1(debug, void, env)
diff --git a/target-avr/machine.c b/target-avr/machine.c
new file mode 100644
index 0000000..3b7fd3d
--- /dev/null
+++ b/target-avr/machine.c
@@ -0,0 +1,116 @@ 
+/*
+ * QEMU AVR CPU
+ *
+ * Copyright (c) 2016 Michael Rolnik
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/lgpl-2.1.html>
+ */
+
+#include "qemu/osdep.h"
+#include "hw/hw.h"
+#include "cpu.h"
+#include "hw/boards.h"
+#include "machine.h"
+#include "migration/qemu-file.h"
+
+static int get_sreg(QEMUFile *f, void *opaque, size_t size)
+{
+    CPUAVRState *env = opaque;
+    uint8_t sreg;
+
+    qemu_get_8s(f, &sreg);
+    cpu_set_sreg(env, sreg);
+    return 0;
+}
+
+static void put_sreg(QEMUFile *f, void *opaque, size_t size)
+{
+    CPUAVRState *env = opaque;
+    uint8_t sreg = cpu_get_sreg(env);
+
+    qemu_put_8s(f, &sreg);
+}
+
+static const VMStateInfo vms_sreg = {
+    .name = "sreg",
+    .get  = get_sreg,
+    .put  = put_sreg,
+};
+
+static int get_segment(QEMUFile *f, void *opaque, size_t size)
+{
+    uint32_t *ramp = opaque;
+    uint8_t temp = *ramp >> 16;
+
+    qemu_get_8s(f, &temp);
+    return 0;
+}
+
+static void put_segment(QEMUFile *f, void *opaque, size_t size)
+{
+    uint32_t *ramp = opaque;
+    uint8_t temp = 0;
+
+    qemu_put_8s(f, &temp);
+    *ramp = ((uint32_t)temp) << 16;
+}
+
+static const VMStateInfo vms_rampD = {
+    .name = "rampD",
+    .get  = get_segment,
+    .put  = put_segment,
+};
+static const VMStateInfo vms_rampX = {
+    .name = "rampX",
+    .get  = get_segment,
+    .put  = put_segment,
+};
+static const VMStateInfo vms_rampY = {
+    .name = "rampY",
+    .get  = get_segment,
+    .put  = put_segment,
+};
+static const VMStateInfo vms_rampZ = {
+    .name = "rampZ",
+    .get  = get_segment,
+    .put  = put_segment,
+};
+static const VMStateInfo vms_eind = {
+    .name = "eind",
+    .get  = get_segment,
+    .put  = put_segment,
+};
+
+const VMStateDescription vms_avr_cpu = {
+    .name               = "cpu",
+    .version_id         = 0,
+    .minimum_version_id = 0,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(env.pc_w, AVRCPU),
+        VMSTATE_UINT32(env.sp, AVRCPU),
+
+        VMSTATE_UINT32_ARRAY(env.r, AVRCPU, AVR_CPU_REGS),
+        VMSTATE_UINT32_ARRAY(env.io, AVRCPU, AVR_CPU_IO_REGS),
+
+        VMSTATE_SINGLE_TEST(env, AVRCPU, NULL, 0, vms_sreg, CPUAVRState),
+        VMSTATE_SINGLE_TEST(env.rampD, AVRCPU, NULL, 0, vms_rampD, uint32_t),
+        VMSTATE_SINGLE_TEST(env.rampX, AVRCPU, NULL, 0, vms_rampX, uint32_t),
+        VMSTATE_SINGLE_TEST(env.rampY, AVRCPU, NULL, 0, vms_rampY, uint32_t),
+        VMSTATE_SINGLE_TEST(env.rampZ, AVRCPU, NULL, 0, vms_rampZ, uint32_t),
+        VMSTATE_SINGLE_TEST(env.eind, AVRCPU, NULL, 0, vms_eind, uint32_t),
+
+        VMSTATE_END_OF_LIST()
+    }
+};
diff --git a/target-avr/machine.h b/target-avr/machine.h
new file mode 100644
index 0000000..4cc8d6b
--- /dev/null
+++ b/target-avr/machine.h
@@ -0,0 +1,21 @@ 
+/*
+ * QEMU AVR CPU
+ *
+ * Copyright (c) 2016 Michael Rolnik
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/lgpl-2.1.html>
+ */
+
+extern const VMStateDescription vmstate_avr_cpu;
diff --git a/target-avr/translate.c b/target-avr/translate.c
new file mode 100644
index 0000000..66ec98b
--- /dev/null
+++ b/target-avr/translate.c
@@ -0,0 +1,291 @@ 
+/*
+ *  QEMU AVR CPU
+ *
+ *  Copyright (c) 2016 Michael Rolnik
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, see
+ *  <http://www.gnu.org/licenses/lgpl-2.1.html>
+ */
+
+#include "qemu/osdep.h"
+
+#include "cpu.h"
+#include "exec/exec-all.h"
+#include "disas/disas.h"
+#include "tcg-op.h"
+#include "exec/cpu_ldst.h"
+
+#include "exec/helper-proto.h"
+#include "exec/helper-gen.h"
+#include "exec/log.h"
+
+typedef struct DisasContext DisasContext;
+typedef struct InstInfo     InstInfo;
+
+/*This is the state at translation time.  */
+struct DisasContext {
+    struct TranslationBlock    *tb;
+
+    /*Routine used to access memory */
+    int                         memidx;
+    int                         bstate;
+    int                         singlestep;
+};
+
+enum {
+    BS_NONE = 0,    /*  Nothing special (none of the below          */
+    BS_STOP = 1,    /*  We want to stop translation for any reason  */
+    BS_BRANCH = 2,    /*  A branch condition is reached               */
+    BS_EXCP = 3,    /*  An exception condition is reached           */
+};
+
+static TCGv_env cpu_env;
+
+static TCGv     cpu_pc;
+
+static TCGv     cpu_Cf;
+static TCGv     cpu_Zf;
+static TCGv     cpu_Nf;
+static TCGv     cpu_Vf;
+static TCGv     cpu_Sf;
+static TCGv     cpu_Hf;
+static TCGv     cpu_Tf;
+static TCGv     cpu_If;
+
+static TCGv     cpu_rampD;
+static TCGv     cpu_rampX;
+static TCGv     cpu_rampY;
+static TCGv     cpu_rampZ;
+
+static TCGv     cpu_io[64];
+static TCGv     cpu_r[32];
+static TCGv     cpu_eind;
+static TCGv     cpu_sp;
+
+#include "exec/gen-icount.h"
+#define REG(x)  (cpu_r[x])
+
+void avr_translate_init(void)
+{
+    int i;
+    static int done_init;
+
+    if (done_init) {
+        return;
+    }
+#define AVR_REG_OFFS(x) offsetof(CPUAVRState, x)
+    cpu_env = tcg_global_reg_new_ptr(TCG_AREG0, "env");
+    cpu_pc = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(pc_w),  "pc");
+    cpu_Cf = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(sregC), "Cf");
+    cpu_Zf = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(sregZ), "Zf");
+    cpu_Nf = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(sregN), "Nf");
+    cpu_Vf = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(sregV), "Vf");
+    cpu_Sf = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(sregS), "Sf");
+    cpu_Hf = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(sregH), "Hf");
+    cpu_Tf = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(sregT), "Tf");
+    cpu_If = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(sregI), "If");
+    cpu_rampD = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(rampD), "rampD");
+    cpu_rampX = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(rampX), "rampX");
+    cpu_rampY = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(rampY), "rampY");
+    cpu_rampZ = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(rampZ), "rampZ");
+    cpu_eind = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(eind),  "eind");
+    cpu_sp = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(sp),    "sp");
+
+    for (i = 0; i < 64; i++) {
+        char    name[16];
+
+        sprintf(name, "io[%d]", i);
+
+        cpu_io[i] = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(io[i]), name);
+    }
+    for (i = 0; i < 32; i++) {
+        char    name[16];
+
+        sprintf(name, "r[%d]", i);
+
+        cpu_r[i] = tcg_global_mem_new_i32(cpu_env, AVR_REG_OFFS(r[i]), name);
+    }
+
+    done_init = 1;
+}
+
+static inline void gen_goto_tb(CPUAVRState *env, DisasContext *ctx, int n,
+                                target_ulong dest)
+{
+    TranslationBlock   *tb;
+
+    tb = ctx->tb;
+
+    if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK)
+        &&  (ctx->singlestep == 0)) {
+        tcg_gen_goto_tb(n);
+        tcg_gen_movi_i32(cpu_pc, dest);
+        tcg_gen_exit_tb((uintptr_t)tb + n);
+    } else {
+        tcg_gen_movi_i32(cpu_pc, dest);
+
+        if (ctx->singlestep) {
+            gen_helper_debug(cpu_env);
+        }
+        tcg_gen_exit_tb(0);
+    }
+}
+
+/*generate intermediate code for basic block 'tb'.  */
+void gen_intermediate_code(CPUAVRState *env, struct TranslationBlock *tb)
+{
+    AVRCPU         *cpu = avr_env_get_cpu(env);
+    CPUState       *cs = CPU(cpu);
+    DisasContext    ctx;
+    target_ulong    pc_start;
+    int             num_insns,
+                    max_insns;
+    target_ulong    cpc;
+    target_ulong    npc;
+
+    pc_start = tb->pc / 2;
+    ctx.tb = tb;
+    ctx.memidx = 0;
+    ctx.bstate = BS_NONE;
+    ctx.singlestep = cs->singlestep_enabled;
+    num_insns = 0;
+    max_insns = tb->cflags & CF_COUNT_MASK;
+
+    if (max_insns == 0) {
+        max_insns = CF_COUNT_MASK;
+    }
+    if (max_insns > TCG_MAX_INSNS) {
+        max_insns = TCG_MAX_INSNS;
+    }
+
+    gen_tb_start(tb);
+
+    /*  decode first instruction    */
+    cpc = pc_start;
+    npc = cpc + 1;
+    do {
+        /*  translate current instruction   */
+        tcg_gen_insn_start(cpc);
+        num_insns++;
+
+        /*  just skip to next instruction   */
+        cpc++;
+        npc++;
+        ctx.bstate = BS_NONE;
+
+        if (unlikely(cpu_breakpoint_test(cs, cpc * 2, BP_ANY))) {
+            tcg_gen_movi_i32(cpu_pc, cpc);
+            gen_helper_debug(cpu_env);
+            ctx.bstate = BS_EXCP;
+            /*The address covered by the breakpoint must be included in
+               [tb->pc, tb->pc + tb->size) in order to for it to be
+               properly cleared -- thus we increment the PC here so that
+               the logic setting tb->size below does the right thing.  */
+            goto done_generating;
+        }
+
+        if (num_insns >= max_insns) {
+            break;      /* max translated instructions limit reached */
+        }
+        if (ctx.singlestep) {
+            break;      /* single step */
+        }
+        if ((cpc & (TARGET_PAGE_SIZE - 1)) == 0) {
+            break;      /* page boundary */
+        }
+    } while (ctx.bstate == BS_NONE && !tcg_op_buf_full());
+
+    if (tb->cflags & CF_LAST_IO) {
+        gen_io_end();
+    }
+
+    if (ctx.singlestep) {
+        if (ctx.bstate == BS_STOP || ctx.bstate == BS_NONE) {
+            tcg_gen_movi_tl(cpu_pc, npc);
+        }
+        gen_helper_debug(cpu_env);
+        tcg_gen_exit_tb(0);
+    } else {
+        switch (ctx.bstate) {
+        case BS_STOP:
+        case BS_NONE:
+            gen_goto_tb(env, &ctx, 0, npc);
+            break;
+        case BS_EXCP:
+            tcg_gen_exit_tb(0);
+            break;
+        default:
+            break;
+        }
+    }
+
+done_generating:
+    env->fullwr = false;
+    gen_tb_end(tb, num_insns);
+
+    tb->size = (npc - pc_start) * 2;
+    tb->icount = num_insns;
+}
+
+void restore_state_to_opc(CPUAVRState *env, TranslationBlock *tb,
+                                target_ulong *data)
+{
+    env->pc_w = data[0];
+}
+
+void avr_cpu_dump_state(CPUState *cs, FILE *f, fprintf_function cpu_fprintf,
+                                int flags)
+{
+    AVRCPU *cpu = AVR_CPU(cs);
+    CPUAVRState *env = &cpu->env;
+
+    cpu_fprintf(f, "\n");
+    cpu_fprintf(f, "PC:    %06x\n", env->pc_w);
+    cpu_fprintf(f, "SP:      %04x\n", env->sp);
+    cpu_fprintf(f, "rampD:     %02x\n", env->rampD >> 16);
+    cpu_fprintf(f, "rampX:     %02x\n", env->rampX >> 16);
+    cpu_fprintf(f, "rampY:     %02x\n", env->rampY >> 16);
+    cpu_fprintf(f, "rampZ:     %02x\n", env->rampZ >> 16);
+    cpu_fprintf(f, "EIND:      %02x\n", env->eind);
+    cpu_fprintf(f, "X:       %02x%02x\n", env->r[27], env->r[26]);
+    cpu_fprintf(f, "Y:       %02x%02x\n", env->r[29], env->r[28]);
+    cpu_fprintf(f, "Z:       %02x%02x\n", env->r[31], env->r[30]);
+    cpu_fprintf(f, "SREG:    [ %c %c %c %c %c %c %c %c ]\n",
+                        env->sregI ? 'I' : '-',
+                        env->sregT ? 'T' : '-',
+                        env->sregH ? 'H' : '-',
+                        env->sregS ? 'S' : '-',
+                        env->sregV ? 'V' : '-',
+                        env->sregN ? '-' : 'N', /*  Zf has negative logic   */
+                        env->sregZ ? 'Z' : '-',
+                        env->sregC ? 'I' : '-');
+
+    cpu_fprintf(f, "\n");
+    for (int i = 0; i < ARRAY_SIZE(env->r); i++) {
+        cpu_fprintf(f, "R[%02d]:  %02x   ", i, env->r[i]);
+
+        if ((i % 8) == 7) {
+            cpu_fprintf(f, "\n");
+        }
+    }
+
+    cpu_fprintf(f, "\n");
+    for (int i = 0; i < ARRAY_SIZE(env->io); i++) {
+        cpu_fprintf(f, "IO[%02d]: %02x   ", i, env->io[i]);
+
+        if ((i % 8) == 7) {
+            cpu_fprintf(f, "\n");
+        }
+    }
+}