Re: [PATCH rc2 01/25] target/avr: Add outward facing interfaces and core

On Sun, Jan 26, 2020 at 2:15 PM Joaquin de Andres <address@hidden> wrote:

Hi! In this mail I only checked the general code and one of the listed
features for the different types of avr. I will check the rest in
following emails.

On 1/24/20 1:51 AM, Philippe Mathieu-Daudé wrote:
> From: Michael Rolnik <address@hidden>
>
> This includes:
> - CPU data structures
> - object model classes and functions
> - migration functions
> - GDB hooks
>
> Co-developed-by: Michael Rolnik <address@hidden>
> Co-developed-by: Sarah Harris <address@hidden>
> Signed-off-by: Michael Rolnik <address@hidden>
> Signed-off-by: Sarah Harris <address@hidden>
> Signed-off-by: Michael Rolnik <address@hidden>
> Acked-by: Igor Mammedov <address@hidden>
> Tested-by: Philippe Mathieu-Daudé <address@hidden>
> Message-Id: <address@hidden>
> Signed-off-by: Richard Henderson <address@hidden>
> ---
> target/avr/cpu-param.h | 37 ++
> target/avr/cpu-qom.h | 54 +++
> target/avr/cpu.h | 258 +++++++++++++
> target/avr/cpu.c | 826 +++++++++++++++++++++++++++++++++++++++++
> target/avr/gdbstub.c | 84 +++++
> target/avr/machine.c | 121 ++++++
> gdb-xml/avr-cpu.xml | 49 +++
> 7 files changed, 1429 insertions(+)
> create mode 100644 target/avr/cpu-param.h
> create mode 100644 target/avr/cpu-qom.h
> create mode 100644 target/avr/cpu.h
> create mode 100644 target/avr/cpu.c
> create mode 100644 target/avr/gdbstub.c
> create mode 100644 target/avr/machine.c
> create mode 100644 gdb-xml/avr-cpu.xml
>
> diff --git a/target/avr/cpu-param.h b/target/avr/cpu-param.h
> new file mode 100644
> index 0000000000..0c29ce4223
> --- /dev/null
> +++ b/target/avr/cpu-param.h
> @@ -0,0 +1,37 @@
> +/*
> + * QEMU AVR CPU
> + *
> + * Copyright (c) 2019 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 AVR_CPU_PARAM_H
> +#define AVR_CPU_PARAM_H
> +
> +#define TARGET_LONG_BITS 32
> +/*
> + * 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
> +
> +
> +#endif
> diff --git a/target/avr/cpu-qom.h b/target/avr/cpu-qom.h
> new file mode 100644
> index 0000000000..e28b58c897
> --- /dev/null
> +++ b/target/avr/cpu-qom.h
> @@ -0,0 +1,54 @@
> +/*
> + * QEMU AVR CPU
> + *
> + * Copyright (c) 2019 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_QOM_H
> +#define QEMU_AVR_QOM_H
> +
> +#include "hw/core/cpu.h"
> +
> +#define TYPE_AVR_CPU "avr-cpu"
> +
> +#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 {
> + /*< private >*/
> + CPUClass parent_class;
> + /*< public >*/
> + DeviceRealize parent_realize;
> + void (*parent_reset)(CPUState *cpu);
> +} AVRCPUClass;
> +
> +typedef struct AVRCPU AVRCPU;
> +
> +
> +#endif /* !defined (QEMU_AVR_CPU_QOM_H) */
> diff --git a/target/avr/cpu.h b/target/avr/cpu.h
> new file mode 100644
> index 0000000000..b74bcf01ae
> --- /dev/null
> +++ b/target/avr/cpu.h
> @@ -0,0 +1,258 @@
> +/*
> + * QEMU AVR CPU
> + *
> + * Copyright (c) 2019 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_H
> +#define QEMU_AVR_CPU_H
> +
> +#include "cpu-qom.h"
> +#include "exec/cpu-defs.h"
> +
> +#define TCG_GUEST_DEFAULT_MO 0
> +#define AVR_CPU_TYPE_SUFFIX "-" TYPE_AVR_CPU
> +#define AVR_CPU_TYPE_NAME(name) (name AVR_CPU_TYPE_SUFFIX)
> +#define CPU_RESOLVING_TYPE TYPE_AVR_CPU
> +
> +/*
> + * AVR has two memory spaces, data & code.
> + * e.g. both have 0 address
> + * ST/LD instructions access data space
> + * LPM/SPM and instruction fetching access code memory space
> + */
> +#define MMU_CODE_IDX 0
> +#define MMU_DATA_IDX 1
> +
> +#define EXCP_RESET 1
> +#define EXCP_INT(n) (EXCP_RESET + (n) + 1)
> +
> +/* Number of CPU registers */
> +#define NUMBER_OF_CPU_REGISTERS 32
> +/* Number of IO registers accessible by ld/st/in/out */
> +#define NUMBER_OF_IO_REGISTERS 64
> +
> +/*
> + * Offsets of AVR memory regions in host memory space.
> + *
> + * This is needed because the AVR has separate code and data address
> + * spaces that both have start from zero but have to go somewhere in
> + * host memory.
> + *
> + * It's also useful to know where some things are, like the IO registers.
> + */
> +/* Flash program memory */
> +#define OFFSET_CODE 0x00000000
> +/* CPU registers, IO registers, and SRAM */
> +#define OFFSET_DATA 0x00800000
> +/* CPU registers specifically, these are mapped at the start of data */
> +#define OFFSET_CPU_REGISTERS OFFSET_DATA
> +/*
> + * IO registers, including status register, stack pointer, and memory
> + * mapped peripherals, mapped just after CPU registers
> + */
> +#define OFFSET_IO_REGISTERS (OFFSET_DATA + NUMBER_OF_CPU_REGISTERS)
> +
> +#define EF_AVR_MACH 0x7F
> +
> +typedef enum AVRFeature {
> + AVR_FEATURE_SRAM,
> +
> + AVR_FEATURE_1_BYTE_PC,
> + AVR_FEATURE_2_BYTE_PC,
> + AVR_FEATURE_3_BYTE_PC,
> +
> + AVR_FEATURE_1_BYTE_SP,
> + AVR_FEATURE_2_BYTE_SP,
> +
> + AVR_FEATURE_BREAK,
> + AVR_FEATURE_DES,
> + AVR_FEATURE_RMW, /* Read Modify Write - XCH LAC LAS LAT */
> +
> + AVR_FEATURE_EIJMP_EICALL,
> + AVR_FEATURE_IJMP_ICALL,
> + AVR_FEATURE_JMP_CALL,
> +
> + AVR_FEATURE_ADIW_SBIW,
> +
> + AVR_FEATURE_SPM,
> + AVR_FEATURE_SPMX,
> +
> + AVR_FEATURE_ELPMX,
> + AVR_FEATURE_ELPM,
> + AVR_FEATURE_LPMX,
> + AVR_FEATURE_LPM,
> +
> + AVR_FEATURE_MOVW,
> + AVR_FEATURE_MUL,
> + AVR_FEATURE_RAMPD,
> + AVR_FEATURE_RAMPX,
> + AVR_FEATURE_RAMPY,
> + AVR_FEATURE_RAMPZ,
> +} AVRFeature;
> +
> +typedef struct CPUAVRState CPUAVRState;
> +
> +struct CPUAVRState {
> + uint32_t pc_w; /* 0x003fffff up to 22 bits */
> +
> + uint32_t sregC; /* 0x00000001 1 bit */
> + uint32_t sregZ; /* 0x00000001 1 bit */
> + uint32_t sregN; /* 0x00000001 1 bit */
> + uint32_t sregV; /* 0x00000001 1 bit */
> + uint32_t sregS; /* 0x00000001 1 bit */
> + uint32_t sregH; /* 0x00000001 1 bit */
> + uint32_t sregT; /* 0x00000001 1 bit */
> + uint32_t sregI; /* 0x00000001 1 bit */
> +
> + 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 r[NUMBER_OF_CPU_REGISTERS]; /* 8 bits each */
> + uint32_t sp; /* 16 bits */
> +
> + uint32_t skip; /* if set skip instruction */
> +
> + uint64_t intsrc; /* interrupt sources */
> + bool fullacc; /* CPU/MEM if true MEM only otherwise */
> +
> + uint32_t features;
> +};

Why not use 'uint8_t' for all sreg bits, ramps, eind and user registers,
and bool for skip flag?

> +
> +/**
> + * AVRCPU:
> + * @env: #CPUAVRState
> + *
> + * A AVR CPU.
> + */
> +typedef struct AVRCPU {
> + /*< private >*/
> + CPUState parent_obj;
> + /*< public >*/
> +
> + CPUNegativeOffsetState neg;
> + CPUAVRState env;
> +} AVRCPU;
> +
> +#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);
> +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);
> +
> +static inline int avr_feature(CPUAVRState *env, AVRFeature feature)
> +{
> + return (env->features & (1U << feature)) != 0;
> +}
> +
> +static inline void avr_set_feature(CPUAVRState *env, int feature)
> +{
> + env->features |= (1U << feature);
> +}
> +
> +#define cpu_list avr_cpu_list
> +#define cpu_signal_handler cpu_avr_signal_handler
> +#define cpu_mmu_index avr_cpu_mmu_index
> +
> +static inline int avr_cpu_mmu_index(CPUAVRState *env, bool ifetch)
> +{
> + return ifetch ? MMU_CODE_IDX : MMU_DATA_IDX;
> +}
> +
> +void avr_cpu_tcg_init(void);
> +
> +void avr_cpu_list(void);
> +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 size,
> + int rw, int mmu_idx);
> +int avr_cpu_memory_rw_debug(CPUState *cs, vaddr address, uint8_t *buf,
> + int len, bool is_write);
> +
> +enum {
> + TB_FLAGS_FULL_ACCESS = 1,
> + TB_FLAGS_SKIP = 2,
> +};
> +
> +static inline void cpu_get_tb_cpu_state(CPUAVRState *env, target_ulong *pc,
> + target_ulong *cs_base, uint32_t *pflags)
> +{
> + uint32_t flags = 0;
> +
> + *pc = env->pc_w * 2;
> + *cs_base = 0;
> +
> + if (env->fullacc) {
> + flags |= TB_FLAGS_FULL_ACCESS;
> + }
> + if (env->skip) {
> + flags |= TB_FLAGS_SKIP;
> + }
> +
> + *pflags = flags;
> +}
> +
> +static inline int cpu_interrupts_enabled(CPUAVRState *env)
> +{
> + return env->sregI != 0;
> +}
> +
> +static inline uint8_t cpu_get_sreg(CPUAVRState *env)
> +{
> + uint8_t sreg;
> + sreg = (env->sregC) << 0
> + | (env->sregZ) << 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;
> + 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;
> +}
> +
> +bool avr_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
> + MMUAccessType access_type, int mmu_idx,
> + bool probe, uintptr_t retaddr);
> +
> +typedef CPUAVRState CPUArchState;
> +typedef AVRCPU ArchCPU;
> +
> +#include "exec/cpu-all.h"
> +
> +const char *avr_flags_to_cpu_type(uint32_t flags, const char *def_cpu_type);
> +
> +#endif /* !defined (QEMU_AVR_CPU_H) */
> diff --git a/target/avr/cpu.c b/target/avr/cpu.c
> new file mode 100644
> index 0000000000..c74c5106fe
> --- /dev/null
> +++ b/target/avr/cpu.c
> @@ -0,0 +1,826 @@
> +/*
> + * QEMU AVR CPU
> + *
> + * Copyright (c) 2019 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 "qemu/qemu-print.h"
> +#include "exec/exec-all.h"
> +#include "cpu.h"
> +#include "disas/dis-asm.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 */
> +}

Isn't it safer to add 'assert(!(value % 2))' before this call?

> +
> +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 */

Same that above.

> +}> +
> +static void avr_cpu_reset(CPUState *cs)
> +{
> + AVRCPU *cpu = AVR_CPU(cs);
> + AVRCPUClass *mcc = AVR_CPU_GET_CLASS(cpu);
> + CPUAVRState *env = &cpu->env;
> +
> + mcc->parent_reset(cs);
> +
> + 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;
> +
> + env->skip = 0;
> +
> + memset(env->r, 0, sizeof(env->r));
> +
> + tlb_flush(cs);
> +}
> +
> +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);
> + Error *local_err = NULL;
> +
> + cpu_exec_realizefn(cs, &local_err);
> + if (local_err != NULL) {
> + error_propagate(errp, local_err);
> + return;
> + }
> + 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)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> +
> + cpu_set_cpustate_pointers(cpu);
> +
> +#ifndef CONFIG_USER_ONLY
> + /* Set the number of interrupts supported by the CPU. */
> + qdev_init_gpio_in(DEVICE(cpu), avr_cpu_set_int,
> + sizeof(cpu->env.intsrc) * 8);
> +#endif
> +}
> +
> +static ObjectClass *avr_cpu_class_by_name(const char *cpu_model)
> +{
> + ObjectClass *oc;
> +
> + oc = object_class_by_name(cpu_model);
> + if (object_class_dynamic_cast(oc, TYPE_AVR_CPU) == NULL ||
> + object_class_is_abstract(oc)) {
> + oc = NULL;
> + }
> + return oc;
> +}
> +
> +static void avr_cpu_dump_state(CPUState *cs, FILE *f, int flags)
> +{
> + AVRCPU *cpu = AVR_CPU(cs);
> + CPUAVRState *env = &cpu->env;
> + int i;
> +
> + qemu_fprintf(f, "\n");
> + qemu_fprintf(f, "PC: %06x\n", env->pc_w);
> + qemu_fprintf(f, "SP: %04x\n", env->sp);
> + qemu_fprintf(f, "rampD: %02x\n", env->rampD >> 16);
> + qemu_fprintf(f, "rampX: %02x\n", env->rampX >> 16);
> + qemu_fprintf(f, "rampY: %02x\n", env->rampY >> 16);
> + qemu_fprintf(f, "rampZ: %02x\n", env->rampZ >> 16);
> + qemu_fprintf(f, "EIND: %02x\n", env->eind >> 16);
> + qemu_fprintf(f, "X: %02x%02x\n", env->r[27], env->r[26]);
> + qemu_fprintf(f, "Y: %02x%02x\n", env->r[29], env->r[28]);
> + qemu_fprintf(f, "Z: %02x%02x\n", env->r[31], env->r[30]);
> + qemu_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' : '-');
> + qemu_fprintf(f, "SKIP: %02x\n", env->skip);
> +
> + qemu_fprintf(f, "\n");
> + for (i = 0; i < ARRAY_SIZE(env->r); i++) {
> + qemu_fprintf(f, "R[%02d]: %02x ", i, env->r[i]);
> +
> + if ((i % 8) == 7) {
> + qemu_fprintf(f, "\n");
> + }
> + }
> + qemu_fprintf(f, "\n");
> +}
> +
> +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->tlb_fill = avr_cpu_tlb_fill;
> + cc->tcg_initialize = avr_cpu_tcg_init;
> + 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;
> + cc->gdb_core_xml_file = "avr-cpu.xml";
> +}
> +
> +/*
> + * Setting features of AVR core type avr1
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * at90s1200, attiny11, attiny12, attiny15, attiny28
> + */
> +static void avr_avr1_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_SP);

Checking features with the datasheet of the listed microcontroller I saw
that the stack is a 3 level deep hardware stack dedicated to subroutines
and interrupts.
Why is the feature 2_BYTE_SP active?

> + avr_set_feature(env, AVR_FEATURE_2_BYTE_PC);
> +}
> +
> +/*
> + * Setting features of AVR core type avr2
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * at90s2313, at90s2323, at90s2333, at90s2343, attiny22, attiny26, at90s4414,
> + * at90s4433, at90s4434, at90s8515, at90c8534, at90s8535
> + */
> +static void avr_avr2_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_IJMP_ICALL);
> + avr_set_feature(env, AVR_FEATURE_ADIW_SBIW);
> + avr_set_feature(env, AVR_FEATURE_SRAM);
> + avr_set_feature(env, AVR_FEATURE_BREAK);
> +
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_PC);
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_SP);

Same. This microcontrollers (only checked with at90s2313 datasheet) use
only SPL, why is the 2_BYTE_SP feature active?

> +}
> +
> +/*
> + * Setting features of AVR core type avr25
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * ata5272, ata6616c, attiny13, attiny13a, attiny2313, attiny2313a, attiny24,
> + * attiny24a, attiny4313, attiny44, attiny44a, attiny441, attiny84, attiny84a,
> + * attiny25, attiny45, attiny85, attiny261, attiny261a, attiny461, attiny461a,
> + * attiny861, attiny861a, attiny43u, attiny87, attiny48, attiny88, attiny828,
> + * attiny841, at86rf401
> + */
> +static void avr_avr25_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_IJMP_ICALL);
> + avr_set_feature(env, AVR_FEATURE_ADIW_SBIW);
> + avr_set_feature(env, AVR_FEATURE_SRAM);
> + avr_set_feature(env, AVR_FEATURE_BREAK);
> +
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_PC);
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_SP);

Same. This microcontrollers (only checked with attiny13 datasheet) use
only SPL, why is the 2_BYTE_SP feature active?

> + avr_set_feature(env, AVR_FEATURE_LPMX);
> + avr_set_feature(env, AVR_FEATURE_MOVW);
> +}
> +
> +/*
> + * Setting features of AVR core type avr3
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * at43usb355, at76c711
> + */
> +static void avr_avr3_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_IJMP_ICALL);
> + avr_set_feature(env, AVR_FEATURE_ADIW_SBIW);
> + avr_set_feature(env, AVR_FEATURE_SRAM);
> + avr_set_feature(env, AVR_FEATURE_BREAK);
> +
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_PC);
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_SP);

Ok. Checked with at43usb355 datasheet.

> + avr_set_feature(env, AVR_FEATURE_JMP_CALL);
> +}
> +
> +/*
> + * Setting features of AVR core type avr31
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * atmega103, at43usb320
> + */
> +static void avr_avr31_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_IJMP_ICALL);
> + avr_set_feature(env, AVR_FEATURE_ADIW_SBIW);
> + avr_set_feature(env, AVR_FEATURE_SRAM);
> + avr_set_feature(env, AVR_FEATURE_BREAK);
> +
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_PC);
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_SP);

Ok. Checked with atmega103 datasheet.

> + avr_set_feature(env, AVR_FEATURE_RAMPZ);
> + avr_set_feature(env, AVR_FEATURE_ELPM);
> + avr_set_feature(env, AVR_FEATURE_JMP_CALL);
> +}
> +
> +/*
> + * Setting features of AVR core type avr35
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * ata5505, ata6617c, ata664251, at90usb82, at90usb162, atmega8u2, atmega16u2,
> + * atmega32u2, attiny167, attiny1634
> + */
> +static void avr_avr35_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_IJMP_ICALL);
> + avr_set_feature(env, AVR_FEATURE_ADIW_SBIW);
> + avr_set_feature(env, AVR_FEATURE_SRAM);
> + avr_set_feature(env, AVR_FEATURE_BREAK);
> +
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_PC);
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_SP);

Ok. Checked with atmega8u2 datasheet.

> + avr_set_feature(env, AVR_FEATURE_JMP_CALL);
> + avr_set_feature(env, AVR_FEATURE_LPMX);
> + avr_set_feature(env, AVR_FEATURE_MOVW);
> +}
> +
> +/*
> + * Setting features of AVR core type avr4
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * ata6285, ata6286, ata6289, ata6612c, atmega8, atmega8a, atmega48, atmega48a,
> + * atmega48p, atmega48pa, atmega48pb, atmega88, atmega88a, atmega88p,
> + * atmega88pa, atmega88pb, atmega8515, atmega8535, atmega8hva, at90pwm1,
> + * at90pwm2, at90pwm2b, at90pwm3, at90pwm3b, at90pwm81
> + */
> +static void avr_avr4_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_IJMP_ICALL);
> + avr_set_feature(env, AVR_FEATURE_ADIW_SBIW);
> + avr_set_feature(env, AVR_FEATURE_SRAM);
> + avr_set_feature(env, AVR_FEATURE_BREAK);
> +
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_PC);
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_SP);

Ok. Checked with atmega8 datasheet.

> + avr_set_feature(env, AVR_FEATURE_LPMX);
> + avr_set_feature(env, AVR_FEATURE_MOVW);
> + avr_set_feature(env, AVR_FEATURE_MUL);
> +}
> +
> +/*
> + * Setting features of AVR core type avr5
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * ata5702m322, ata5782, ata5790, ata5790n, ata5791, ata5795, ata5831, ata6613c,
> + * ata6614q, ata8210, ata8510, atmega16, atmega16a, atmega161, atmega162,
> + * atmega163, atmega164a, atmega164p, atmega164pa, atmega165, atmega165a,
> + * atmega165p, atmega165pa, atmega168, atmega168a, atmega168p, atmega168pa,
> + * atmega168pb, atmega169, atmega169a, atmega169p, atmega169pa, atmega16hvb,
> + * atmega16hvbrevb, atmega16m1, atmega16u4, atmega32a, atmega32, atmega323,
> + * atmega324a, atmega324p, atmega324pa, atmega325, atmega325a, atmega325p,
> + * atmega325pa, atmega3250, atmega3250a, atmega3250p, atmega3250pa, atmega328,
> + * atmega328p, atmega328pb, atmega329, atmega329a, atmega329p, atmega329pa,
> + * atmega3290, atmega3290a, atmega3290p, atmega3290pa, atmega32c1, atmega32m1,
> + * atmega32u4, atmega32u6, atmega406, atmega64, atmega64a, atmega640, atmega644,
> + * atmega644a, atmega644p, atmega644pa, atmega645, atmega645a, atmega645p,
> + * atmega6450, atmega6450a, atmega6450p, atmega649, atmega649a, atmega649p,
> + * atmega6490, atmega16hva, atmega16hva2, atmega32hvb, atmega6490a, atmega6490p,
> + * atmega64c1, atmega64m1, atmega64hve, atmega64hve2, atmega64rfr2,
> + * atmega644rfr2, atmega32hvbrevb, at90can32, at90can64, at90pwm161, at90pwm216,
> + * at90pwm316, at90scr100, at90usb646, at90usb647, at94k, m3000
> + */
> +static void avr_avr5_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_IJMP_ICALL);
> + avr_set_feature(env, AVR_FEATURE_ADIW_SBIW);
> + avr_set_feature(env, AVR_FEATURE_SRAM);
> + avr_set_feature(env, AVR_FEATURE_BREAK);
> +
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_PC);
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_SP);

Ok. Checked with atmega64 datasheet.

> + avr_set_feature(env, AVR_FEATURE_JMP_CALL);
> + avr_set_feature(env, AVR_FEATURE_LPMX);
> + avr_set_feature(env, AVR_FEATURE_MOVW);
> + avr_set_feature(env, AVR_FEATURE_MUL);
> +}
> +
> +/*
> + * Setting features of AVR core type avr51
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * atmega128, atmega128a, atmega1280, atmega1281, atmega1284, atmega1284p,
> + * atmega128rfa1, atmega128rfr2, atmega1284rfr2, at90can128, at90usb1286,
> + * at90usb1287
> + */
> +static void avr_avr51_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_IJMP_ICALL);
> + avr_set_feature(env, AVR_FEATURE_ADIW_SBIW);
> + avr_set_feature(env, AVR_FEATURE_SRAM);
> + avr_set_feature(env, AVR_FEATURE_BREAK);
> +
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_PC);
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_SP);

Ok. Checked with atmega128 datasheet.

> + avr_set_feature(env, AVR_FEATURE_RAMPZ);
> + avr_set_feature(env, AVR_FEATURE_ELPMX);
> + avr_set_feature(env, AVR_FEATURE_ELPM);
> + avr_set_feature(env, AVR_FEATURE_JMP_CALL);
> + avr_set_feature(env, AVR_FEATURE_LPMX);
> + avr_set_feature(env, AVR_FEATURE_MOVW);
> + avr_set_feature(env, AVR_FEATURE_MUL);
> +}
> +
> +/*
> + * Setting features of AVR core type avr6
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * atmega2560, atmega2561, atmega256rfr2, atmega2564rfr2
> + */
> +static void avr_avr6_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_IJMP_ICALL);
> + avr_set_feature(env, AVR_FEATURE_ADIW_SBIW);
> + avr_set_feature(env, AVR_FEATURE_SRAM);
> + avr_set_feature(env, AVR_FEATURE_BREAK);
> +
> + avr_set_feature(env, AVR_FEATURE_3_BYTE_PC);
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_SP);

Ok. Checked with atmega2560 datasheet.

> + avr_set_feature(env, AVR_FEATURE_RAMPZ);
> + avr_set_feature(env, AVR_FEATURE_EIJMP_EICALL);
> + avr_set_feature(env, AVR_FEATURE_ELPMX);
> + avr_set_feature(env, AVR_FEATURE_ELPM);
> + avr_set_feature(env, AVR_FEATURE_JMP_CALL);
> + avr_set_feature(env, AVR_FEATURE_LPMX);
> + avr_set_feature(env, AVR_FEATURE_MOVW);
> + avr_set_feature(env, AVR_FEATURE_MUL);
> +}
> +
> +/*
> + * Setting features of AVR core type avrtiny
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * attiny4, attiny5, attiny9, attiny10, attiny20, attiny40
> + */
> +static void avr_avrtiny_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_IJMP_ICALL);
> + avr_set_feature(env, AVR_FEATURE_BREAK);
> +
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_PC);
> + avr_set_feature(env, AVR_FEATURE_1_BYTE_SP);

The attiny4 datasheet writes:
"The AVR stack pointer is implemented as two 8-bit registers in the I/O
space. The number of bits actually used is implementation dependent."
Not using AVR_FEATURE_2_BYTE_SP isn't leaving out the ones with two
bytes SP?

> +}
> +
> +/*
> + * Setting features of AVR core type xmega2
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * atxmega8e5, atxmega16a4, atxmega16d4, atxmega16e5, atxmega32a4, atxmega32c3,
> + * atxmega32d3, atxmega32d4, atxmega16a4u, atxmega16c4, atxmega32a4u,
> + * atxmega32c4, atxmega32e5
> + */
> +static void avr_xmega2_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_IJMP_ICALL);
> + avr_set_feature(env, AVR_FEATURE_ADIW_SBIW);
> + avr_set_feature(env, AVR_FEATURE_SRAM);
> + avr_set_feature(env, AVR_FEATURE_BREAK);
> +
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_PC);
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_SP);

Ok. Checked with atxmega8e5 datasheet.

> + avr_set_feature(env, AVR_FEATURE_JMP_CALL);
> + avr_set_feature(env, AVR_FEATURE_LPMX);
> + avr_set_feature(env, AVR_FEATURE_MOVW);
> + avr_set_feature(env, AVR_FEATURE_MUL);
> + avr_set_feature(env, AVR_FEATURE_RMW);
> +}
> +
> +/*
> + * Setting features of AVR core type xmega3
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * attiny212, attiny214, attiny412, attiny414, attiny416, attiny417, attiny814,
> + * attiny816, attiny817, attiny1614, attiny1616, attiny1617, attiny3214,
> + * attiny3216, attiny3217, atmega808, atmega809, atmega1608, atmega1609,
> + * atmega3208, atmega3209, atmega4808, atmega4809
> + */
> +static void avr_xmega3_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_IJMP_ICALL);
> + avr_set_feature(env, AVR_FEATURE_ADIW_SBIW);
> + avr_set_feature(env, AVR_FEATURE_SRAM);
> + avr_set_feature(env, AVR_FEATURE_BREAK);
> +
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_PC);
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_SP);

Ok. Checked with attiny212 datasheet.

> + avr_set_feature(env, AVR_FEATURE_JMP_CALL);
> + avr_set_feature(env, AVR_FEATURE_LPMX);
> + avr_set_feature(env, AVR_FEATURE_MOVW);
> + avr_set_feature(env, AVR_FEATURE_MUL);
> + avr_set_feature(env, AVR_FEATURE_RMW);
> +}
> +
> +/*
> + * Setting features of AVR core type xmega4
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * atxmega64a3, atxmega64d3, atxmega64a3u, atxmega64a4u, atxmega64b1,
> + * atxmega64b3, atxmega64c3, atxmega64d4
> + */
> +static void avr_xmega4_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_IJMP_ICALL);
> + avr_set_feature(env, AVR_FEATURE_ADIW_SBIW);
> + avr_set_feature(env, AVR_FEATURE_SRAM);
> + avr_set_feature(env, AVR_FEATURE_BREAK);
> +
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_PC);
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_SP);

Ok. I couldn't find an exact definition of the SP length but it says
that the SRAM is used as stack. The max length of ram being 16KB.
Checked with atxmega64a3 datasheet.

> + avr_set_feature(env, AVR_FEATURE_ELPMX);
> + avr_set_feature(env, AVR_FEATURE_ELPM);
> + avr_set_feature(env, AVR_FEATURE_JMP_CALL);
> + avr_set_feature(env, AVR_FEATURE_LPMX);
> + avr_set_feature(env, AVR_FEATURE_MOVW);
> + avr_set_feature(env, AVR_FEATURE_MUL);
> + avr_set_feature(env, AVR_FEATURE_RMW);
> +}
> +
> +/*
> + * Setting features of AVR core type xmega5
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * atxmega64a1, atxmega64a1u
> + */
> +static void avr_xmega5_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_IJMP_ICALL);
> + avr_set_feature(env, AVR_FEATURE_ADIW_SBIW);
> + avr_set_feature(env, AVR_FEATURE_SRAM);
> + avr_set_feature(env, AVR_FEATURE_BREAK);
> +
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_PC);
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_SP);

Ok. Checked with atxmega64a1 datasheet.

> + avr_set_feature(env, AVR_FEATURE_RAMPD);
> + avr_set_feature(env, AVR_FEATURE_RAMPX);
> + avr_set_feature(env, AVR_FEATURE_RAMPY);
> + avr_set_feature(env, AVR_FEATURE_RAMPZ);
> + avr_set_feature(env, AVR_FEATURE_ELPMX);
> + avr_set_feature(env, AVR_FEATURE_ELPM);
> + avr_set_feature(env, AVR_FEATURE_JMP_CALL);
> + avr_set_feature(env, AVR_FEATURE_LPMX);
> + avr_set_feature(env, AVR_FEATURE_MOVW);
> + avr_set_feature(env, AVR_FEATURE_MUL);
> + avr_set_feature(env, AVR_FEATURE_RMW);
> +}
> +
> +/*
> + * Setting features of AVR core type xmega6
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * atxmega128a3, atxmega128d3, atxmega192a3, atxmega192d3, atxmega256a3,
> + * atxmega256a3b, atxmega256a3bu, atxmega256d3, atxmega128a3u, atxmega128b1,
> + * atxmega128b3, atxmega128c3, atxmega128d4, atxmega192a3u, atxmega192c3,
> + * atxmega256a3u, atxmega256c3, atxmega384c3, atxmega384d3
> + */
> +static void avr_xmega6_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_IJMP_ICALL);
> + avr_set_feature(env, AVR_FEATURE_ADIW_SBIW);
> + avr_set_feature(env, AVR_FEATURE_SRAM);
> + avr_set_feature(env, AVR_FEATURE_BREAK);
> +
> + avr_set_feature(env, AVR_FEATURE_3_BYTE_PC);
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_SP);

Ok. I couldn't find an exact definition of the SP length but it says
that the SRAM is used as stack. The max length of ram being 16KB.
Checked with atxmega128a3 datasheet.

> + avr_set_feature(env, AVR_FEATURE_RAMPZ);
> + avr_set_feature(env, AVR_FEATURE_EIJMP_EICALL);
> + avr_set_feature(env, AVR_FEATURE_ELPMX);
> + avr_set_feature(env, AVR_FEATURE_ELPM);
> + avr_set_feature(env, AVR_FEATURE_JMP_CALL);
> + avr_set_feature(env, AVR_FEATURE_LPMX);
> + avr_set_feature(env, AVR_FEATURE_MOVW);
> + avr_set_feature(env, AVR_FEATURE_MUL);
> + avr_set_feature(env, AVR_FEATURE_RMW);
> +}
> +
> +/*
> + * Setting features of AVR core type xmega7
> + * --------------------------------------
> + *
> + * This type of AVR core is present in the following AVR MCUs:
> + *
> + * atxmega128a1, atxmega128a1u, atxmega128a4u
> + */
> +static void avr_xmega7_initfn(Object *obj)
> +{
> + AVRCPU *cpu = AVR_CPU(obj);
> + CPUAVRState *env = &cpu->env;
> +
> + avr_set_feature(env, AVR_FEATURE_LPM);
> + avr_set_feature(env, AVR_FEATURE_IJMP_ICALL);
> + avr_set_feature(env, AVR_FEATURE_ADIW_SBIW);
> + avr_set_feature(env, AVR_FEATURE_SRAM);
> + avr_set_feature(env, AVR_FEATURE_BREAK);
> +
> + avr_set_feature(env, AVR_FEATURE_3_BYTE_PC);
> + avr_set_feature(env, AVR_FEATURE_2_BYTE_SP);

Ok. Checked with atxmega128a1 datasheet.

> + avr_set_feature(env, AVR_FEATURE_RAMPD);
> + avr_set_feature(env, AVR_FEATURE_RAMPX);
> + avr_set_feature(env, AVR_FEATURE_RAMPY);
> + avr_set_feature(env, AVR_FEATURE_RAMPZ);
> + avr_set_feature(env, AVR_FEATURE_EIJMP_EICALL);
> + avr_set_feature(env, AVR_FEATURE_ELPMX);
> + avr_set_feature(env, AVR_FEATURE_ELPM);
> + avr_set_feature(env, AVR_FEATURE_JMP_CALL);
> + avr_set_feature(env, AVR_FEATURE_LPMX);
> + avr_set_feature(env, AVR_FEATURE_MOVW);
> + avr_set_feature(env, AVR_FEATURE_MUL);
> + avr_set_feature(env, AVR_FEATURE_RMW);
> +}
> +
> +typedef struct AVRCPUInfo {
> + const char *name;
> + void (*initfn)(Object *obj);
> +} AVRCPUInfo;
> +
> +
> +static void avr_cpu_list_entry(gpointer data, gpointer user_data)
> +{
> + const char *typename = object_class_get_name(OBJECT_CLASS(data));
> +
> + qemu_printf("%s\n", typename);
> +}
> +
> +void avr_cpu_list(void)
> +{
> + GSList *list;
> + list = object_class_get_list_sorted(TYPE_AVR_CPU, false);
> + g_slist_foreach(list, avr_cpu_list_entry, NULL);
> + g_slist_free(list);
> +}
> +
> +#define DEFINE_AVR_CPU_TYPE(model, initfn) \
> + { \
> + .parent = TYPE_AVR_CPU, \
> + .instance_init = initfn, \
> + .name = AVR_CPU_TYPE_NAME(model), \
> + }
> +
> +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,
> + },
> + DEFINE_AVR_CPU_TYPE("avrtiny", avr_avrtiny_initfn),
> + DEFINE_AVR_CPU_TYPE("avr1", avr_avr1_initfn),
> + DEFINE_AVR_CPU_TYPE("avr2", avr_avr2_initfn),
> + DEFINE_AVR_CPU_TYPE("avr25", avr_avr25_initfn),
> + DEFINE_AVR_CPU_TYPE("avr3", avr_avr3_initfn),
> + DEFINE_AVR_CPU_TYPE("avr31", avr_avr31_initfn),
> + DEFINE_AVR_CPU_TYPE("avr35", avr_avr35_initfn),
> + DEFINE_AVR_CPU_TYPE("avr4", avr_avr4_initfn),
> + DEFINE_AVR_CPU_TYPE("avr5", avr_avr5_initfn),
> + DEFINE_AVR_CPU_TYPE("avr51", avr_avr51_initfn),
> + DEFINE_AVR_CPU_TYPE("avr6", avr_avr6_initfn),
> + DEFINE_AVR_CPU_TYPE("xmega2", avr_xmega2_initfn),
> + DEFINE_AVR_CPU_TYPE("xmega3", avr_xmega3_initfn),
> + DEFINE_AVR_CPU_TYPE("xmega4", avr_xmega4_initfn),
> + DEFINE_AVR_CPU_TYPE("xmega5", avr_xmega5_initfn),
> + DEFINE_AVR_CPU_TYPE("xmega6", avr_xmega6_initfn),
> + DEFINE_AVR_CPU_TYPE("xmega7", avr_xmega7_initfn),
> +};
> +
> +const char *avr_flags_to_cpu_type(uint32_t flags, const char *def_cpu_type)
> +{
> + switch (flags & EF_AVR_MACH) {
> + case bfd_mach_avr1:
> + return AVR_CPU_TYPE_NAME("avr1");
> + case bfd_mach_avr2:
> + return AVR_CPU_TYPE_NAME("avr2");
> + case bfd_mach_avr25:
> + return AVR_CPU_TYPE_NAME("avr25");
> + case bfd_mach_avr3:
> + return AVR_CPU_TYPE_NAME("avr3");
> + case bfd_mach_avr31:
> + return AVR_CPU_TYPE_NAME("avr31");
> + case bfd_mach_avr35:
> + return AVR_CPU_TYPE_NAME("avr35");
> + case bfd_mach_avr4:
> + return AVR_CPU_TYPE_NAME("avr4");
> + case bfd_mach_avr5:
> + return AVR_CPU_TYPE_NAME("avr5");
> + case bfd_mach_avr51:
> + return AVR_CPU_TYPE_NAME("avr51");
> + case bfd_mach_avr6:
> + return AVR_CPU_TYPE_NAME("avr6");
> + case bfd_mach_avrtiny:
> + return AVR_CPU_TYPE_NAME("avrtiny");
> + case bfd_mach_avrxmega2:
> + return AVR_CPU_TYPE_NAME("xmega2");
> + case bfd_mach_avrxmega3:
> + return AVR_CPU_TYPE_NAME("xmega3");
> + case bfd_mach_avrxmega4:
> + return AVR_CPU_TYPE_NAME("xmega4");
> + case bfd_mach_avrxmega5:
> + return AVR_CPU_TYPE_NAME("xmega5");
> + case bfd_mach_avrxmega6:
> + return AVR_CPU_TYPE_NAME("xmega6");
> + case bfd_mach_avrxmega7:
> + return AVR_CPU_TYPE_NAME("xmega7");
> + default:
> + return def_cpu_type;
> + }
> +}
> +
> +DEFINE_TYPES(avr_cpu_type_info)
> diff --git a/target/avr/gdbstub.c b/target/avr/gdbstub.c
> new file mode 100644
> index 0000000000..733184c08f
> --- /dev/null
> +++ b/target/avr/gdbstub.c
> @@ -0,0 +1,84 @@
> +/*
> + * QEMU AVR CPU
> + *
> + * Copyright (c) 2019 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 "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;
> +
> + /* R */
> + if (n < 32) {
> + env->r[n] = *mem_buf;
> + return 1;
> + }
> +
> + /* SREG */
> + if (n == 32) {
> + cpu_set_sreg(env, *mem_buf);
> + return 1;
> + }
> +
> + /* SP */
> + if (n == 33) {
> + env->sp = lduw_p(mem_buf);
> + return 2;
> + }
> +
> + /* PC */
> + if (n == 34) {
> + env->pc_w = ldl_p(mem_buf) / 2;
> + return 4;
> + }
> +
> + return 0;
> +}
> diff --git a/target/avr/machine.c b/target/avr/machine.c
> new file mode 100644
> index 0000000000..ba44bd042b
> --- /dev/null
> +++ b/target/avr/machine.c
> @@ -0,0 +1,121 @@
> +/*
> + * QEMU AVR CPU
> + *
> + * Copyright (c) 2019 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 "migration/cpu.h"
> +
> +static int get_sreg(QEMUFile *f, void *opaque, size_t size,
> + const VMStateField *field)
> +{
> + CPUAVRState *env = opaque;
> + uint8_t sreg;
> +
> + sreg = qemu_get_byte(f);
> + cpu_set_sreg(env, sreg);
> + return 0;
> +}
> +
> +static int put_sreg(
> + QEMUFile *f, void *opaque, size_t size,
> + const VMStateField *field, QJSON *vmdesc)
> +{
> + CPUAVRState *env = opaque;
> + uint8_t sreg = cpu_get_sreg(env);
> +
> + qemu_put_byte(f, sreg);
> + return 0;
> +}
> +
> +static const VMStateInfo vms_sreg = {
> + .name = "sreg",
> + .get = get_sreg,
> + .put = put_sreg,
> +};
> +
> +static int get_segment(
> + QEMUFile *f, void *opaque, size_t size, const VMStateField *field)
> +{
> + uint32_t *ramp = opaque;
> + uint8_t temp;
> +
> + temp = qemu_get_byte(f);
> + *ramp = ((uint32_t)temp) << 16;
> + return 0;
> +}
> +
> +static int put_segment(
> + QEMUFile *f, void *opaque, size_t size,
> + const VMStateField *field, QJSON *vmdesc)
> +{
> + uint32_t *ramp = opaque;
> + uint8_t temp = *ramp >> 16;
> +
> + qemu_put_byte(f, temp);
> + return 0;
> +}
> +
> +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(env.skip, AVRCPU),
> +
> + VMSTATE_UINT32_ARRAY(env.r, AVRCPU, NUMBER_OF_CPU_REGISTERS),
> +
> + VMSTATE_SINGLE(env, AVRCPU, 0, vms_sreg, CPUAVRState),
> + VMSTATE_SINGLE(env.rampD, AVRCPU, 0, vms_rampD, uint32_t),
> + VMSTATE_SINGLE(env.rampX, AVRCPU, 0, vms_rampX, uint32_t),
> + VMSTATE_SINGLE(env.rampY, AVRCPU, 0, vms_rampY, uint32_t),
> + VMSTATE_SINGLE(env.rampZ, AVRCPU, 0, vms_rampZ, uint32_t),
> + VMSTATE_SINGLE(env.eind, AVRCPU, 0, vms_eind, uint32_t),
> +
> + VMSTATE_END_OF_LIST()
> + }
> +};
> diff --git a/gdb-xml/avr-cpu.xml b/gdb-xml/avr-cpu.xml
> new file mode 100644
> index 0000000000..c4747f5b40
> --- /dev/null
> +++ b/gdb-xml/avr-cpu.xml
> @@ -0,0 +1,49 @@
> +<?xml version="1.0"?>
> +
> +
> +
> +
> +<!DOCTYPE feature SYSTEM "gdb-target.dtd">
> +<feature name="org.gnu.gdb.riscv.cpu">
> + <reg name="r0" bitsize="8" type="int" regnum="0"/>
> + <reg name="r1" bitsize="8" type="int"/>
> + <reg name="r2" bitsize="8" type="int"/>
> + <reg name="r3" bitsize="8" type="int"/>
> + <reg name="r4" bitsize="8" type="int"/>
> + <reg name="r5" bitsize="8" type="int"/>
> + <reg name="r6" bitsize="8" type="int"/>
> + <reg name="r7" bitsize="8" type="int"/>
> + <reg name="r8" bitsize="8" type="int"/>
> + <reg name="r9" bitsize="8" type="int"/>
> + <reg name="r10" bitsize="8" type="int"/>
> + <reg name="r11" bitsize="8" type="int"/>
> + <reg name="r12" bitsize="8" type="int"/>
> + <reg name="r13" bitsize="8" type="int"/>
> + <reg name="r14" bitsize="8" type="int"/>
> + <reg name="r15" bitsize="8" type="int"/>
> + <reg name="r16" bitsize="8" type="int"/>
> + <reg name="r17" bitsize="8" type="int"/>
> + <reg name="r18" bitsize="8" type="int"/>
> + <reg name="r19" bitsize="8" type="int"/>
> + <reg name="r20" bitsize="8" type="int"/>
> + <reg name="r21" bitsize="8" type="int"/>
> + <reg name="r22" bitsize="8" type="int"/>
> + <reg name="r23" bitsize="8" type="int"/>
> + <reg name="r24" bitsize="8" type="int"/>
> + <reg name="r25" bitsize="8" type="int"/>
> + <reg name="r26" bitsize="8" type="int"/>
> + <reg name="r27" bitsize="8" type="int"/>
> + <reg name="r28" bitsize="8" type="int"/>
> + <reg name="r29" bitsize="8" type="int"/>
> + <reg name="r30" bitsize="8" type="int"/>
> + <reg name="r31" bitsize="8" type="int"/>
> + <reg name="sreg" bitsize="8" type="int"/>
> + <reg name="sp" bitsize="8" type="int"/>
> + <reg name="pc" bitsize="8" type="int"/>
> +</feature>
>

General concern: why is there an AVR_FEATURE_1_BYTE_PC when the code
does nothing with it?

--Joa

From:	Michael Rolnik
Subject:	Re: [PATCH rc2 01/25] target/avr: Add outward facing interfaces and core CPU logic
Date:	Mon, 27 Jan 2020 10:53:20 +0200