* [RFC v1 0/1] Implement AVR WDT (watchdog timer)
@ 2021-05-05 21:18 Michael Rolnik
2021-05-05 21:18 ` [RFC 1/1] Implement AVR watchdog timer Michael Rolnik
0 siblings, 1 reply; 4+ messages in thread
From: Michael Rolnik @ 2021-05-05 21:18 UTC (permalink / raw)
To: qemu-devel; +Cc: Michael Rolnik, me, konrad, richard.henderson, f4bug
1. Initial implementation of AVR WDT
There are two issues with this implementation so I need your help here
a. when I configure the WDT to fire an interrupt every 15ms it actually happens every 6 instructions
b. when I specify --icount shift=0 qemu stucks
changes since v1
1. correct RW or RW1C behavior is implemented
2. icount functionality is fixed
3. I still observe something strange, it takes AVR 150 instructions to simulate 15ms
*** BLURB HERE ***
Michael Rolnik (1):
Implement AVR watchdog timer
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
--
2.25.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* [RFC 1/1] Implement AVR watchdog timer
2021-05-05 21:18 [RFC v1 0/1] Implement AVR WDT (watchdog timer) Michael Rolnik
@ 2021-05-05 21:18 ` Michael Rolnik
2021-05-13 12:27 ` Pavel Dovgalyuk
0 siblings, 1 reply; 4+ messages in thread
From: Michael Rolnik @ 2021-05-05 21:18 UTC (permalink / raw)
To: qemu-devel; +Cc: Michael Rolnik, me, konrad, richard.henderson, f4bug
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
---
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 <f4bug@amsat.org>
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
+ * <http://www.gnu.org/licenses/lgpl-2.1.html>
+ */
+
+#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)
+
+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
+ * <http://www.gnu.org/licenses/lgpl-2.1.html>
+ */
+
+#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 {
+ /* <private> */
+ SysBusDevice parent_obj;
+
+ /* <public> */
+ MemoryRegion iomem;
+ MemoryRegion imsk_iomem;
+ MemoryRegion ifr_iomem;
+ QEMUTimer *timer;
+ qemu_irq irq;
+
+ /* registers */
+ uint8_t csr;
+};
+
+#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;
@@ -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) {
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [RFC 1/1] Implement AVR watchdog timer
2021-05-05 21:18 ` [RFC 1/1] Implement AVR watchdog timer Michael Rolnik
@ 2021-05-13 12:27 ` Pavel Dovgalyuk
2021-05-14 7:20 ` Michael Rolnik
0 siblings, 1 reply; 4+ messages in thread
From: Pavel Dovgalyuk @ 2021-05-13 12:27 UTC (permalink / raw)
To: Michael Rolnik, qemu-devel; +Cc: me, konrad, richard.henderson, f4bug
On 06.05.2021 00:18, Michael Rolnik wrote:
> Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
> ---
> 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 <f4bug@amsat.org>
> 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
> + * <http://www.gnu.org/licenses/lgpl-2.1.html>
> + */
> +
> +#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
> + * <http://www.gnu.org/licenses/lgpl-2.1.html>
> + */
> +
> +#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 {
> + /* <private> */
> + SysBusDevice parent_obj;
> +
> + /* <public> */
> + 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) {
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [RFC 1/1] Implement AVR watchdog timer
2021-05-13 12:27 ` Pavel Dovgalyuk
@ 2021-05-14 7:20 ` Michael Rolnik
0 siblings, 0 replies; 4+ messages in thread
From: Michael Rolnik @ 2021-05-14 7:20 UTC (permalink / raw)
To: Pavel Dovgalyuk
Cc: Joaquin de Andres, Fred Konrad, Richard Henderson,
QEMU Developers, Philippe Mathieu-Daudé
[-- Attachment #1: Type: text/plain, Size: 27121 bytes --]
Ok, thanks.
Sent from my cell phone, please ignore typos
On Thu, May 13, 2021, 3:27 PM Pavel Dovgalyuk <pavel.dovgalyuk@ispras.ru>
wrote:
> On 06.05.2021 00:18, Michael Rolnik wrote:
> > Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
> > ---
> > 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 <f4bug@amsat.org>
> > 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
> > + * <http://www.gnu.org/licenses/lgpl-2.1.html>
> > + */
> > +
> > +#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
> > + * <http://www.gnu.org/licenses/lgpl-2.1.html>
> > + */
> > +
> > +#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 {
> > + /* <private> */
> > + SysBusDevice parent_obj;
> > +
> > + /* <public> */
> > + 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) {
> >
>
>
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2021-05-05 21:18 [RFC v1 0/1] Implement AVR WDT (watchdog timer) Michael Rolnik
2021-05-05 21:18 ` [RFC 1/1] Implement AVR watchdog timer Michael Rolnik
2021-05-13 12:27 ` Pavel Dovgalyuk
2021-05-14 7:20 ` Michael Rolnik
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