From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BEB59C433B4 for ; Thu, 13 May 2021 12:44:34 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2279D613CA for ; Thu, 13 May 2021 12:44:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2279D613CA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=ispras.ru Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:59456 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lhAhd-0002Qv-4T for qemu-devel@archiver.kernel.org; Thu, 13 May 2021 08:44:33 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60966) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lhARh-0002Mv-CJ for qemu-devel@nongnu.org; Thu, 13 May 2021 08:28:05 -0400 Received: from mail.ispras.ru ([83.149.199.84]:49862) by eggs.gnu.org with esmtps (TLS1.2:DHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lhARc-0005Rx-B6 for qemu-devel@nongnu.org; Thu, 13 May 2021 08:28:05 -0400 Received: from [192.168.0.92] (unknown [62.118.138.151]) by mail.ispras.ru (Postfix) with ESMTPSA id E77BD40D403D; Thu, 13 May 2021 12:27:53 +0000 (UTC) Subject: Re: [RFC 1/1] Implement AVR watchdog timer To: Michael Rolnik , qemu-devel@nongnu.org References: <20210505211849.101005-1-mrolnik@gmail.com> <20210505211849.101005-2-mrolnik@gmail.com> From: Pavel Dovgalyuk Message-ID: Date: Thu, 13 May 2021 15:27:53 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <20210505211849.101005-2-mrolnik@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=83.149.199.84; envelope-from=pavel.dovgalyuk@ispras.ru; helo=mail.ispras.ru X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, NICE_REPLY_A=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: me@xcancerberox.com.ar, konrad@adacore.com, richard.henderson@linaro.org, f4bug@amsat.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 06.05.2021 00:18, Michael Rolnik wrote: > Signed-off-by: Michael Rolnik > --- > MAINTAINERS | 2 + > hw/avr/Kconfig | 1 + > hw/avr/atmega.c | 15 +- > hw/avr/atmega.h | 2 + > hw/watchdog/Kconfig | 3 + > hw/watchdog/avr_wdt.c | 274 ++++++++++++++++++++++++++++++++++ > hw/watchdog/meson.build | 2 + > hw/watchdog/trace-events | 5 + > include/hw/watchdog/avr_wdt.h | 47 ++++++ > target/avr/cpu.c | 3 + > target/avr/cpu.h | 1 + > target/avr/helper.c | 7 +- > target/avr/translate.c | 38 ++++- > 13 files changed, 391 insertions(+), 9 deletions(-) > create mode 100644 hw/watchdog/avr_wdt.c > create mode 100644 include/hw/watchdog/avr_wdt.h > > diff --git a/MAINTAINERS b/MAINTAINERS > index 4c05ff8bba..e1fce736d2 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -1052,6 +1052,8 @@ F: include/hw/timer/avr_timer16.h > F: hw/timer/avr_timer16.c > F: include/hw/misc/avr_power.h > F: hw/misc/avr_power.c > +F: include/hw/watchdog/avr_wdt.h > +F: hw/watchdog/avr_wdt.c > > Arduino > M: Philippe Mathieu-Daudé > diff --git a/hw/avr/Kconfig b/hw/avr/Kconfig > index d31298c3cc..9939e4902f 100644 > --- a/hw/avr/Kconfig > +++ b/hw/avr/Kconfig > @@ -3,6 +3,7 @@ config AVR_ATMEGA_MCU > select AVR_TIMER16 > select AVR_USART > select AVR_POWER > + select AVR_WDT > > config ARDUINO > select AVR_ATMEGA_MCU > diff --git a/hw/avr/atmega.c b/hw/avr/atmega.c > index 44c6afebbb..31ceb1c21c 100644 > --- a/hw/avr/atmega.c > +++ b/hw/avr/atmega.c > @@ -28,6 +28,7 @@ enum AtmegaPeripheral { > GPIOG, GPIOH, GPIOI, GPIOJ, GPIOK, GPIOL, > USART0, USART1, USART2, USART3, > TIMER0, TIMER1, TIMER2, TIMER3, TIMER4, TIMER5, > + WDT, > PERIFMAX > }; > > @@ -75,6 +76,7 @@ static const peripheral_cfg dev168_328[PERIFMAX] = { > [GPIOD] = { 0x29 }, > [GPIOC] = { 0x26 }, > [GPIOB] = { 0x23 }, > + [WDT] = { 0x60 }, > }, dev1280_2560[PERIFMAX] = { > [USART3] = { 0x130, POWER1, 2 }, > [TIMER5] = { 0x120, POWER1, 5, 0x73, 0x3a, true }, > @@ -99,6 +101,7 @@ static const peripheral_cfg dev168_328[PERIFMAX] = { > [GPIOC] = { 0x26 }, > [GPIOB] = { 0x23 }, > [GPIOA] = { 0x20 }, > + [WDT] = { 0x60 }, > }; > > enum AtmegaIrq { > @@ -118,6 +121,7 @@ enum AtmegaIrq { > TIMER4_COMPC_IRQ, TIMER4_OVF_IRQ, > TIMER5_CAPT_IRQ, TIMER5_COMPA_IRQ, TIMER5_COMPB_IRQ, > TIMER5_COMPC_IRQ, TIMER5_OVF_IRQ, > + WATCHDOG_TIMER_IRQ, > IRQ_COUNT > }; > > @@ -133,6 +137,7 @@ enum AtmegaIrq { > #define TIMER_OVF_IRQ(n) (n * TIMER_IRQ_COUNT + TIMER0_OVF_IRQ) > > static const uint8_t irq168_328[IRQ_COUNT] = { > + [WATCHDOG_TIMER_IRQ] = 7, > [TIMER2_COMPA_IRQ] = 8, > [TIMER2_COMPB_IRQ] = 9, > [TIMER2_OVF_IRQ] = 10, > @@ -147,6 +152,7 @@ static const uint8_t irq168_328[IRQ_COUNT] = { > [USART0_DRE_IRQ] = 20, > [USART0_TXC_IRQ] = 21, > }, irq1280_2560[IRQ_COUNT] = { > + [WATCHDOG_TIMER_IRQ] = 13, > [TIMER2_COMPA_IRQ] = 14, > [TIMER2_COMPB_IRQ] = 15, > [TIMER2_OVF_IRQ] = 16, > @@ -344,10 +350,17 @@ static void atmega_realize(DeviceState *dev, Error **errp) > g_free(devname); > } > > + /* Watchdog Timer */ > + object_initialize_child(OBJECT(dev), "wdt", &s->wdt, TYPE_AVR_WDT); > + sysbus_realize(SYS_BUS_DEVICE(&s->wdt), &error_abort); > + sysbus_mmio_map(SYS_BUS_DEVICE(&s->wdt), 0, > + OFFSET_DATA + mc->dev[WDT].addr); > + qdev_connect_gpio_out_named(cpudev, "wdr", 0, > + qdev_get_gpio_in_named(DEVICE(&s->wdt), "wdr", 0)); > + > create_unimplemented_device("avr-twi", OFFSET_DATA + 0x0b8, 6); > create_unimplemented_device("avr-adc", OFFSET_DATA + 0x078, 8); > create_unimplemented_device("avr-ext-mem-ctrl", OFFSET_DATA + 0x074, 2); > - create_unimplemented_device("avr-watchdog", OFFSET_DATA + 0x060, 1); > create_unimplemented_device("avr-spi", OFFSET_DATA + 0x04c, 3); > create_unimplemented_device("avr-eeprom", OFFSET_DATA + 0x03f, 3); > } > diff --git a/hw/avr/atmega.h b/hw/avr/atmega.h > index a99ee15c7e..60bbd44bdd 100644 > --- a/hw/avr/atmega.h > +++ b/hw/avr/atmega.h > @@ -13,6 +13,7 @@ > > #include "hw/char/avr_usart.h" > #include "hw/timer/avr_timer16.h" > +#include "hw/watchdog/avr_wdt.h" > #include "hw/misc/avr_power.h" > #include "target/avr/cpu.h" > #include "qom/object.h" > @@ -45,6 +46,7 @@ struct AtmegaMcuState { > AVRMaskState pwr[POWER_MAX]; > AVRUsartState usart[USART_MAX]; > AVRTimer16State timer[TIMER_MAX]; > + AVRWatchdogState wdt; > uint64_t xtal_freq_hz; > }; > > diff --git a/hw/watchdog/Kconfig b/hw/watchdog/Kconfig > index 66e1d029e3..e0f89d2fe0 100644 > --- a/hw/watchdog/Kconfig > +++ b/hw/watchdog/Kconfig > @@ -20,3 +20,6 @@ config WDT_IMX2 > > config WDT_SBSA > bool > + > +config AVR_WDT > + bool > diff --git a/hw/watchdog/avr_wdt.c b/hw/watchdog/avr_wdt.c > new file mode 100644 > index 0000000000..cbd6457c8b > --- /dev/null > +++ b/hw/watchdog/avr_wdt.c > @@ -0,0 +1,274 @@ > +/* > + * AVR watchdog > + * > + * Copyright (c) 2021 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 > + * > + */ > + > +#include "qemu/osdep.h" > +#include "qapi/error.h" > +#include "qemu/log.h" > +#include "hw/irq.h" > +#include "hw/watchdog/avr_wdt.h" > +#include "trace.h" > +#include "target/avr/cpu.h" > +#include "sysemu/runstate.h" > + > +/* Field masks */ > +#define WDTCSR_MASK_WDP0 0x01 > +#define WDTCSR_MASK_WDP1 0x02 > +#define WDTCSR_MASK_WDP2 0x04 > +#define WDTCSR_MASK_WDE 0x08 > +#define WDTCSR_MASK_WDCE 0x10 > +#define WDTCSR_MASK_WDP3 0x20 > +#define WDTCSR_MASK_WDIE 0x40 > +#define WDTCSR_MASK_WDIF 0x80 > + > +#define WDTCSR_SHFT_WDP0 0x00 > +#define WDTCSR_SHFT_WDP1 0x01 > +#define WDTCSR_SHFT_WDP2 0x02 > +#define WDTCSR_SHFT_WDE 0x03 > +#define WDTCSR_SHFT_WDCE 0x04 > +#define WDTCSR_SHFT_WDP3 0x05 > +#define WDTCSR_SHFT_WDIE 0x06 > +#define WDTCSR_SHFT_WDIF 0x07 > + > +#define MCUSR_MASK_WDRF 0x04 > +#define MCUSR_ADDR (OFFSET_DATA + 0x55) > + > +/* Helper macros */ > +#define WDP0(csr) ((csr & WDTCSR_MASK_WDP0) >> WDTCSR_SHFT_WDP0) > +#define WDP1(csr) ((csr & WDTCSR_MASK_WDP1) >> WDTCSR_SHFT_WDP1) > +#define WDP2(csr) ((csr & WDTCSR_MASK_WDP2) >> WDTCSR_SHFT_WDP2) > +#define WDP3(csr) ((csr & WDTCSR_MASK_WDP3) >> WDTCSR_SHFT_WDP3) > +#define WDP(csr) ((WDP3(csr) << 3) | (WDP2(csr) << 2) | \ > + (WDP1(csr) << 1) | (WDP0(csr) << 0)) > +#define WDIE(csr) ((csr & WDTCSR_MASK_WDIE) >> WDTCSR_SHFT_WDIE) > +#define WDE(csr) ((csr & WDTCSR_MASK_WDE) >> WDTCSR_SHFT_WDE) > +#define WCE(csr) ((csr & WDTCSR_MASK_WCE) >> WDTCSR_SHFT_WCE) > + > +#define DB_PRINT(fmt, args...) /* Nothing */ > + > +#define MS2NS(n) ((n) * 1000000ull) I think there is SCALE_MS define for that. > + > +static void set_bits(uint8_t *addr, uint8_t bits) > +{ > + *addr |= bits; > +} > + > +static void rst_bits(uint8_t *addr, uint8_t bits) > +{ > + *addr &= ~bits; > +} > + > +static void avr_wdt_reset_alarm(AVRWatchdogState *wdt) > +{ > + uint32_t csr = wdt->csr; > + int wdp = WDP(csr); > + > + if (WDIE(csr) == 0 && WDE(csr) == 0) { > + /* watchdog is stopped */ > + return; > + } > + > + timer_mod_ns(wdt->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + > + (MS2NS(15) << wdp)); > +} > + > +static void avr_wdt_interrupt(void *opaque) > +{ > + AVRWatchdogState *wdt = opaque; > + int8_t csr = wdt->csr; > + > + if (WDIE(csr) == 1) { > + /* Interrupt Mode */ > + set_bits(&wdt->csr, WDTCSR_MASK_WDIF); > + qemu_set_irq(wdt->irq, 1); > + trace_avr_wdt_interrupt(); > + rst_bits(&wdt->csr, WDTCSR_MASK_WDIF | WDTCSR_MASK_WDIE); > + } > + > + if (WDE(csr) == 1) { > + /* System Reset Mode */ > + qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET); > + } > + > + avr_wdt_reset_alarm(wdt); > +} > + > +static void avr_wdt_reset(DeviceState *dev) > +{ > + AVRWatchdogState *wdt = AVR_WDT(dev); > + > + wdt->csr = 0; > + qemu_set_irq(wdt->irq, 0); > + avr_wdt_reset_alarm(wdt); > +} > + > +static uint64_t avr_wdt_read(void *opaque, hwaddr offset, unsigned size) > +{ > + assert(size == 1); > + AVRWatchdogState *wdt = opaque; > + uint8_t retval = wdt->csr; > + > + trace_avr_wdt_read(offset, retval); > + > + return (uint64_t)retval; > +} > + > +static void avr_wdt_write(void *opaque, hwaddr offset, > + uint64_t val64, unsigned size) > +{ > + assert(size == 1); > + AVRWatchdogState *wdt = opaque; > + uint8_t val = (uint8_t)val64; > + uint8_t set1 = val; /* bits that should be set to 1 */ > + uint8_t set0 = ~val;/* bits that should be set to 0 */ > + uint8_t mcusr = 0; > + > + /* > + * Bit 7 - WDIF: Watchdog Interrupt Flag > + * This bit is set when a time-out occurs in the Watchdog Timer and the > + * Watchdog Timer is configured for interrupt. WDIF is cleared by hardware > + * when executing the corresponding interrupt handling vector. > + * Alternatively, WDIF is cleared by writing a logic one to the flag. > + * When the I-bit in SREG and WDIE are set, the Watchdog Time-out Interrupt > + * is executed. > + */ > + if (val & WDTCSR_MASK_WDIF) { > + rst_bits(&set1, WDTCSR_MASK_WDIF); /* don't set 1 */ > + set_bits(&set0, WDTCSR_MASK_WDIF); /* set 0 */ > + } else { > + rst_bits(&set1, WDTCSR_MASK_WDIF); /* don't set 1 */ > + rst_bits(&set0, WDTCSR_MASK_WDIF); /* don't set 0 */ > + } > + > + /* > + * Bit 4 - WDCE: Watchdog Change Enable > + * This bit is used in timed sequences for changing WDE and prescaler > + * bits. To clear the WDE bit, and/or change the prescaler bits, > + * WDCE must be set. > + * Once written to one, hardware will clear WDCE after four clock cycles. > + */ > + if (!(val & WDTCSR_MASK_WDCE)) { > + uint8_t bits = WDTCSR_MASK_WDE | WDTCSR_MASK_WDP0 | WDTCSR_MASK_WDP1 | > + WDTCSR_MASK_WDP2 | WDTCSR_MASK_WDP3; > + rst_bits(&set1, bits); > + rst_bits(&set0, bits); > + } > + > + /* > + * Bit 3 - WDE: Watchdog System Reset Enable > + * WDE is overridden by WDRF in MCUSR. This means that WDE is always set > + * when WDRF is set. To clear WDE, WDRF must be cleared first. This > + * feature ensures multiple resets during conditions causing failure, and > + * a safe start-up after the failure. > + */ > + cpu_physical_memory_read(MCUSR_ADDR, &mcusr, sizeof(mcusr)); > + if (mcusr & MCUSR_MASK_WDRF) { > + set_bits(&set1, WDTCSR_MASK_WDE); > + rst_bits(&set0, WDTCSR_MASK_WDE); > + } > + > + /* update CSR value */ > + assert((set0 & set1) == 0); > + > + val = wdt->csr; > + set_bits(&val, set1); > + rst_bits(&val, set0); > + wdt->csr = val; > + trace_avr_wdt_write(offset, val); > + avr_wdt_reset_alarm(wdt); > + > + /* > + * Bit 6 - WDIE: Watchdog Interrupt Enable > + * When this bit is written to one and the I-bit in the Status Register is > + * set, the Watchdog Interrupt is enabled. If WDE is cleared in > + * combination with this setting, the Watchdog Timer is in Interrupt Mode, > + * and the corresponding interrupt is executed if time-out in the Watchdog > + * Timer occurs. > + * If WDE is set, the Watchdog Timer is in Interrupt and System Reset Mode. > + * The first time-out in the Watchdog Timer will set WDIF. Executing the > + * corresponding interrupt vector will clear WDIE and WDIF automatically by > + * hardware (the Watchdog goes to System Reset Mode). This is useful for > + * keeping the Watchdog Timer security while using the interrupt. To stay > + * in Interrupt and System Reset Mode, WDIE must be set after each > + * interrupt. This should however not be done within the interrupt service > + * routine itself, as this might compromise the safety-function of the > + * Watchdog System Reset mode. If the interrupt is not executed before the > + * next time-out, a System Reset will be applied. > + */ > + if ((val & WDTCSR_MASK_WDIE) && (wdt->csr & WDTCSR_MASK_WDIF)) { > + avr_wdt_interrupt(opaque); > + } > +} > + > +static const MemoryRegionOps avr_wdt_ops = { > + .read = avr_wdt_read, > + .write = avr_wdt_write, > + .endianness = DEVICE_NATIVE_ENDIAN, > + .impl = {.max_access_size = 1} > +}; > + > +static void avr_wdt_wdr(void *opaque, int irq, int level) > +{ > + AVRWatchdogState *wdt = AVR_WDT(opaque); > + > + avr_wdt_reset_alarm(wdt); > +} > + > +static void avr_wdt_init(Object *obj) > +{ > + AVRWatchdogState *s = AVR_WDT(obj); > + > + sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq); > + > + memory_region_init_io(&s->iomem, obj, &avr_wdt_ops, > + s, "avr-wdt", 0xa); > + > + sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem); > + qdev_init_gpio_in_named(DEVICE(s), avr_wdt_wdr, "wdr", 1); > +} > + > +static void avr_wdt_realize(DeviceState *dev, Error **errp) > +{ > + AVRWatchdogState *s = AVR_WDT(dev); > + > + s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, avr_wdt_interrupt, s); > +} > + > +static void avr_wdt_class_init(ObjectClass *klass, void *data) > +{ > + DeviceClass *dc = DEVICE_CLASS(klass); > + > + dc->reset = avr_wdt_reset; > + dc->realize = avr_wdt_realize; > +} > + > +static const TypeInfo avr_wdt_info = { > + .name = TYPE_AVR_WDT, > + .parent = TYPE_SYS_BUS_DEVICE, > + .instance_size = sizeof(AVRWatchdogState), > + .instance_init = avr_wdt_init, > + .class_init = avr_wdt_class_init, > +}; > + > +static void avr_wdt_register_types(void) > +{ > + type_register_static(&avr_wdt_info); > +} > + > +type_init(avr_wdt_register_types) > diff --git a/hw/watchdog/meson.build b/hw/watchdog/meson.build > index 054c403dea..8db2be8317 100644 > --- a/hw/watchdog/meson.build > +++ b/hw/watchdog/meson.build > @@ -6,3 +6,5 @@ softmmu_ss.add(when: 'CONFIG_WDT_DIAG288', if_true: files('wdt_diag288.c')) > softmmu_ss.add(when: 'CONFIG_ASPEED_SOC', if_true: files('wdt_aspeed.c')) > softmmu_ss.add(when: 'CONFIG_WDT_IMX2', if_true: files('wdt_imx2.c')) > softmmu_ss.add(when: 'CONFIG_WDT_SBSA', if_true: files('sbsa_gwdt.c')) > + > +specific_ss.add(when: 'CONFIG_AVR_WDT', if_true: files('avr_wdt.c')) > diff --git a/hw/watchdog/trace-events b/hw/watchdog/trace-events > index 3124ca1f1b..ac14773179 100644 > --- a/hw/watchdog/trace-events > +++ b/hw/watchdog/trace-events > @@ -5,3 +5,8 @@ cmsdk_apb_watchdog_read(uint64_t offset, uint64_t data, unsigned size) "CMSDK AP > cmsdk_apb_watchdog_write(uint64_t offset, uint64_t data, unsigned size) "CMSDK APB watchdog write: offset 0x%" PRIx64 " data 0x%" PRIx64 " size %u" > cmsdk_apb_watchdog_reset(void) "CMSDK APB watchdog: reset" > cmsdk_apb_watchdog_lock(uint32_t lock) "CMSDK APB watchdog: lock %" PRIu32 > + > +# avr_wdt.c > +avr_wdt_read(uint8_t addr, uint8_t value) "wdt read addr:%u value:%u" > +avr_wdt_write(uint8_t addr, uint8_t value) "wdt write addr:%u value:%u" > +avr_wdt_interrupt(void) "" > diff --git a/include/hw/watchdog/avr_wdt.h b/include/hw/watchdog/avr_wdt.h > new file mode 100644 > index 0000000000..8433663013 > --- /dev/null > +++ b/include/hw/watchdog/avr_wdt.h > @@ -0,0 +1,47 @@ > +/* > + * AVR watchdog > + * > + * Copyright (c) 2021 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 > + * > + */ > + > +#ifndef HW_WATCHDOG_AVR_WDT_H > +#define HW_WATCHDOG_AVR_WDT_H > + > +#include "hw/sysbus.h" > +#include "qemu/timer.h" > +#include "hw/hw.h" > +#include "qom/object.h" > + > +#define TYPE_AVR_WDT "avr-wdt" > +OBJECT_DECLARE_SIMPLE_TYPE(AVRWatchdogState, AVR_WDT) > + > +struct AVRWatchdogState { > + /* */ > + SysBusDevice parent_obj; > + > + /* */ > + MemoryRegion iomem; > + MemoryRegion imsk_iomem; > + MemoryRegion ifr_iomem; > + QEMUTimer *timer; > + qemu_irq irq; > + > + /* registers */ > + uint8_t csr; > +}; > + You should add vmstate which includes timer and csr. It will allow reverse debugging available with icount enabled. > +#endif /* HW_WATCHDOG_AVR_WDT_H */ > diff --git a/target/avr/cpu.c b/target/avr/cpu.c > index 0f4596932b..d5eb785833 100644 > --- a/target/avr/cpu.c > +++ b/target/avr/cpu.c > @@ -131,6 +131,9 @@ static void avr_cpu_initfn(Object *obj) > /* Set the number of interrupts supported by the CPU. */ > qdev_init_gpio_in(DEVICE(cpu), avr_cpu_set_int, > sizeof(cpu->env.intsrc) * 8); > + > + /* register watchdog timer reset interrupt */ > + qdev_init_gpio_out_named(DEVICE(cpu), &cpu->wdr, "wdr", 1); > } > > static ObjectClass *avr_cpu_class_by_name(const char *cpu_model) > diff --git a/target/avr/cpu.h b/target/avr/cpu.h > index d148e8c75a..f8f5641c8b 100644 > --- a/target/avr/cpu.h > +++ b/target/avr/cpu.h > @@ -152,6 +152,7 @@ typedef struct AVRCPU { > > CPUNegativeOffsetState neg; > CPUAVRState env; > + qemu_irq wdr; /* reset WDT */ > } AVRCPU; > > extern const struct VMStateDescription vms_avr_cpu; > diff --git a/target/avr/helper.c b/target/avr/helper.c > index 35e1019594..dd88057e5f 100644 > --- a/target/avr/helper.c > +++ b/target/avr/helper.c > @@ -24,6 +24,7 @@ > #include "exec/exec-all.h" > #include "exec/address-spaces.h" > #include "exec/helper-proto.h" > +#include "hw/irq.h" > > bool avr_cpu_exec_interrupt(CPUState *cs, int interrupt_request) > { > @@ -188,11 +189,9 @@ void helper_break(CPUAVRState *env) > > void helper_wdr(CPUAVRState *env) > { > - CPUState *cs = env_cpu(env); > + AVRCPU *cpu = env_archcpu(env); > > - /* WD is not implemented yet, placeholder */ > - cs->exception_index = EXCP_DEBUG; > - cpu_loop_exit(cs); > + qemu_set_irq(cpu->wdr, 1); > } > > /* > diff --git a/target/avr/translate.c b/target/avr/translate.c > index 850c5941d9..b7b716f4a0 100644 > --- a/target/avr/translate.c > +++ b/target/avr/translate.c > @@ -1411,6 +1411,9 @@ static bool trans_SBIC(DisasContext *ctx, arg_SBIC *a) > { > TCGv temp = tcg_const_i32(a->reg); > > + if (tb_cflags(ctx->tb) & CF_USE_ICOUNT) { > + gen_io_start(); > + } > gen_helper_inb(temp, cpu_env, temp); > tcg_gen_andi_tl(temp, temp, 1 << a->bit); > ctx->skip_cond = TCG_COND_EQ; Translation should stop at inb-related instructions in icount mode, because icount is valid only at the end of the block. Reading it in the middle makes execution non-deterministic. > @@ -1429,6 +1432,9 @@ static bool trans_SBIS(DisasContext *ctx, arg_SBIS *a) > { > TCGv temp = tcg_const_i32(a->reg); > > + if (tb_cflags(ctx->tb) & CF_USE_ICOUNT) { > + gen_io_start(); > + } > gen_helper_inb(temp, cpu_env, temp); > tcg_gen_andi_tl(temp, temp, 1 << a->bit); > ctx->skip_cond = TCG_COND_NE; > @@ -1611,6 +1617,9 @@ static TCGv gen_get_zaddr(void) > static void gen_data_store(DisasContext *ctx, TCGv data, TCGv addr) > { > if (ctx->tb->flags & TB_FLAGS_FULL_ACCESS) { > + if (tb_cflags(ctx->tb) & CF_USE_ICOUNT) { > + gen_io_start(); > + } > gen_helper_fullwr(cpu_env, data, addr); > } else { > tcg_gen_qemu_st8(data, addr, MMU_DATA_IDX); /* mem[addr] = data */ > @@ -1620,6 +1629,9 @@ static void gen_data_store(DisasContext *ctx, TCGv data, TCGv addr) > static void gen_data_load(DisasContext *ctx, TCGv data, TCGv addr) > { > if (ctx->tb->flags & TB_FLAGS_FULL_ACCESS) { > + if (tb_cflags(ctx->tb) & CF_USE_ICOUNT) { > + gen_io_start(); > + } > gen_helper_fullrd(data, cpu_env, addr); > } else { > tcg_gen_qemu_ld8u(data, addr, MMU_DATA_IDX); /* data = mem[addr] */ > @@ -2325,6 +2337,9 @@ static bool trans_IN(DisasContext *ctx, arg_IN *a) > TCGv Rd = cpu_r[a->rd]; > TCGv port = tcg_const_i32(a->imm); > > + if (tb_cflags(ctx->tb) & CF_USE_ICOUNT) { > + gen_io_start(); > + } > gen_helper_inb(Rd, cpu_env, port); > > tcg_temp_free_i32(port); > @@ -2341,6 +2356,9 @@ static bool trans_OUT(DisasContext *ctx, arg_OUT *a) > TCGv Rd = cpu_r[a->rd]; > TCGv port = tcg_const_i32(a->imm); > > + if (tb_cflags(ctx->tb) & CF_USE_ICOUNT) { > + gen_io_start(); > + } > gen_helper_outb(cpu_env, port, Rd); > > tcg_temp_free_i32(port); > @@ -2641,6 +2659,9 @@ static bool trans_SBI(DisasContext *ctx, arg_SBI *a) > TCGv data = tcg_temp_new_i32(); > TCGv port = tcg_const_i32(a->reg); > > + if (tb_cflags(ctx->tb) & CF_USE_ICOUNT) { > + gen_io_start(); > + } > gen_helper_inb(data, cpu_env, port); > tcg_gen_ori_tl(data, data, 1 << a->bit); > gen_helper_outb(cpu_env, port, data); > @@ -2660,6 +2681,9 @@ static bool trans_CBI(DisasContext *ctx, arg_CBI *a) > TCGv data = tcg_temp_new_i32(); > TCGv port = tcg_const_i32(a->reg); > > + if (tb_cflags(ctx->tb) & CF_USE_ICOUNT) { > + gen_io_start(); > + } > gen_helper_inb(data, cpu_env, port); > tcg_gen_andi_tl(data, data, ~(1 << a->bit)); > gen_helper_outb(cpu_env, port, data); > @@ -2830,6 +2854,9 @@ static bool trans_SLEEP(DisasContext *ctx, arg_SLEEP *a) > */ > static bool trans_WDR(DisasContext *ctx, arg_WDR *a) > { > + if (tb_cflags(ctx->tb) & CF_USE_ICOUNT) { > + gen_io_start(); > + } > gen_helper_wdr(cpu_env); > > return true; > @@ -2919,6 +2946,9 @@ void gen_intermediate_code(CPUState *cs, TranslationBlock *tb, int max_insns) > * This flag is set by ST/LD instruction we will regenerate it ONLY > * with mem/cpu memory access instead of mem access > */ > + if (tb_cflags(tb) & CF_USE_ICOUNT) { > + gen_io_start(); > + } > max_insns = 1; > } > if (ctx.singlestep) { > @@ -2955,6 +2985,10 @@ void gen_intermediate_code(CPUState *cs, TranslationBlock *tb, int max_insns) > goto done_generating; > } > > + if (num_insns == max_insns && (tb_cflags(tb) & CF_LAST_IO)) { > + gen_io_start(); > + } > + > /* Conditionally skip the next instruction, if indicated. */ > if (ctx.skip_cond != TCG_COND_NEVER) { > skip_label = gen_new_label(); > @@ -2998,10 +3032,6 @@ void gen_intermediate_code(CPUState *cs, TranslationBlock *tb, int max_insns) > && (ctx.npc - pc_start) * 2 < TARGET_PAGE_SIZE - 4 > && !tcg_op_buf_full()); > > - if (tb->cflags & CF_LAST_IO) { > - gen_io_end(); > - } > - > bool nonconst_skip = canonicalize_skip(&ctx); > > switch (ctx.bstate) { >