Ubuntu内核打开硬件watchdog

淩亂°似流年 2024-03-31 13:12 67阅读 0赞

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#### 文章目录 ####

*  前言
 *  一、watchdog是什么？
 *   *  1.硬件看门狗
     *  2.软件件看门狗
 *  二、编译内核
 *   *  1.添加配置
     *  2.开始编译
     *  3.安装内核
     *  4.软硬结合
 *  总结

--------------------

## 前言 ##

最近在部署linux系统的时候发现一个问题，kernel出现超时未响应。瞬间一万只草泥马奔腾，我心想内核这么强大的东西出现bug也能被我撞到，不管你信不信内核不是万能的，只要是人写的东西就有bug。所以我经过刻苦钻研终于成功打开了watchdog，而且是硬件的watchdog。本文使用的设备是firefl的aio-rk3399c，其他的设备可以参考我的方法，并结合一些钻研精神。

关于怎么打开软件watchdog请参考我的另一篇文章[linux watchdog配置][linux watchdog]

这两篇文章结合可以完成硬件watchdog和软件watchdog的结合使用，关键时刻有奇效。

--------------------

## 一、watchdog是什么？ ##

虽然看到这篇文章的人肯定已经知道是什么了，但是这里我还是要赘述下，给不知道的人看。

### 1.硬件看门狗 ###

看门狗，又叫 watchdog，从本质上来说就是一个定时器电路，一般有一个输入和一个输出，其中输入叫做喂狗，输出一般连接到另外一个部分的复位端，一般是连接到单片机。 看门狗的功能是定期的查看芯片内部的情况，一旦发生错误就向芯片发出重启信号。看门狗命令在程序的中断中拥有最高的优先级。

解释下：硬件看门狗集成在SOC里，通过驱动让它工作，理论上除非掉电或者电路物理损坏，绝不会出现失败的可能，所以这个是最后一道屏障。

### 2.软件件看门狗 ###

这里说两种，一种是集成在内核的module名字叫soft\_watchdog，还有一种是linux纯软件实现的watchdog，本质上是一个daemon。前者要使用的话需要在内核编译的时候打开才行，后者直接在文件系统里安装就行了。差别我没有测出来，我觉的是权限和保活，前者作为内核的module稳定性肯定不必要多说了，后者是上层软件稳定性有待观察。今天我们不需要它太稳定，因为我们有办法解决这些问题。

## 二、编译内核 ##

因为各硬件之间的差异太大，这里我的教程以firefly的aio-rk3399c来作为示例，默认你已经从官方下载了源代码（firefly是开源的），如果你有对接人的话你可以直接跟他说让他帮你打开watchdog，这样你就不需要自己操作了。

### 1.添加配置 ###

先进入源代码目录，正常的firefly的源代码目录应该是下面这样。

husz@insigma:/data/users/husz/rk3399_linux_release_v2.5.1_20210301$ ls
    app  buildroot  build.sh  debian  device  distro  docs  envsetup.sh  external  kernel  Makefile  mkfirmware.sh  prebuilts  rkbin  rkflash.sh  rockdev  tools  u-boot  ubuntu_rootfs  yocto

`我们所有的操作都是基于build.sh这个脚本来的。`

我们需要操作的两个文件是：  
`内核配置文件`  
kernel/arch/arm64/configs/firefly\_linux\_defconfig  
配置有点多，这些配置就是内核需要打开的功能。

# CONFIG_LOCALVERSION_AUTO is not set
    CONFIG_DEFAULT_HOSTNAME="localhost"
    CONFIG_SYSVIPC=y
    CONFIG_POSIX_MQUEUE=y
    CONFIG_FHANDLE=y
    CONFIG_AUDIT=y
    CONFIG_AUDITSYSCALL=y
    CONFIG_NO_HZ=y
    CONFIG_HIGH_RES_TIMERS=y
    CONFIG_LOG_BUF_SHIFT=18
    CONFIG_CGROUPS=y
    CONFIG_CGROUP_FREEZER=y
    CONFIG_CGROUP_PIDS=y
    CONFIG_CGROUP_DEVICE=y
    CONFIG_CPUSETS=y
    CONFIG_CGROUP_CPUACCT=y
    CONFIG_MEMCG=y
    CONFIG_MEMCG_SWAP=y
    CONFIG_MEMCG_KMEM=y
    CONFIG_CGROUP_HUGETLB=y
    CONFIG_CGROUP_PERF=y
    CONFIG_CGROUP_SCHED=y
    CONFIG_CFS_BANDWIDTH=y
    CONFIG_RT_GROUP_SCHED=y
    CONFIG_BLK_CGROUP=y
    CONFIG_NAMESPACES=y
    CONFIG_USER_NS=y
    CONFIG_DEFAULT_USE_ENERGY_AWARE=y
    CONFIG_BLK_DEV_INITRD=y
    CONFIG_CC_OPTIMIZE_FOR_SIZE=y
    CONFIG_EMBEDDED=y
    # CONFIG_COMPAT_BRK is not set
    CONFIG_PROFILING=y
    CONFIG_MODULES=y
    CONFIG_MODULE_FORCE_LOAD=y
    CONFIG_MODULE_UNLOAD=y
    CONFIG_MODULE_FORCE_UNLOAD=y
    CONFIG_BLK_DEV_THROTTLING=y
    CONFIG_PARTITION_ADVANCED=y
    CONFIG_CFQ_GROUP_IOSCHED=y
    CONFIG_ARCH_ROCKCHIP=y
    CONFIG_PCI=y
    CONFIG_PCI_MSI=y
    CONFIG_ROCKCHIP_PCIE_DMA_OBJ=y
    CONFIG_PCIE_ROCKCHIP=y
    CONFIG_PCIEPORTBUS=y
    # CONFIG_PCIEASPM is not set
    # CONFIG_ARM64_ERRATUM_826319 is not set
    # CONFIG_ARM64_ERRATUM_827319 is not set
    # CONFIG_ARM64_ERRATUM_824069 is not set
    # CONFIG_ARM64_ERRATUM_819472 is not set
    # CONFIG_ARM64_ERRATUM_832075 is not set
    # CONFIG_CAVIUM_ERRATUM_22375 is not set
    # CONFIG_CAVIUM_ERRATUM_23154 is not set
    CONFIG_SCHED_MC=y
    CONFIG_NR_CPUS=8
    CONFIG_PREEMPT_VOLUNTARY=y
    CONFIG_HZ_1000=y
    # CONFIG_COMPACTION is not set
    CONFIG_DEFAULT_MMAP_MIN_ADDR=32768
    CONFIG_ZSMALLOC=y
    CONFIG_SECCOMP=y
    CONFIG_ARMV8_DEPRECATED=y
    CONFIG_SWP_EMULATION=y
    CONFIG_CP15_BARRIER_EMULATION=y
    CONFIG_SETEND_EMULATION=y
    # CONFIG_EFI is not set
    CONFIG_COMPAT=y
    CONFIG_PM_DEBUG=y
    CONFIG_PM_ADVANCED_DEBUG=y
    CONFIG_WQ_POWER_EFFICIENT_DEFAULT=y
    CONFIG_CPU_IDLE=y
    CONFIG_ARM_CPUIDLE=y
    CONFIG_CPU_FREQ=y
    CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE=y
    CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
    CONFIG_CPU_FREQ_GOV_POWERSAVE=y
    CONFIG_CPU_FREQ_GOV_USERSPACE=y
    CONFIG_CPU_FREQ_GOV_ONDEMAND=y
    CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y
    CONFIG_CPUFREQ_DT=y
    CONFIG_ARM_ROCKCHIP_CPUFREQ=y
    CONFIG_NET=y
    CONFIG_PACKET=y
    CONFIG_UNIX=y
    CONFIG_XFRM_USER=y
    CONFIG_XFRM_STATISTICS=y
    CONFIG_NET_KEY=y
    CONFIG_INET=y
    CONFIG_IP_MULTICAST=y
    CONFIG_IP_ADVANCED_ROUTER=y
    CONFIG_IP_FIB_TRIE_STATS=y
    CONFIG_IP_MULTIPLE_TABLES=y
    CONFIG_IP_ROUTE_MULTIPATH=y
    CONFIG_IP_ROUTE_VERBOSE=y
    CONFIG_NET_IPGRE_BROADCAST=y
    CONFIG_IP_MROUTE=y
    CONFIG_IP_PIMSM_V1=y
    CONFIG_IP_PIMSM_V2=y
    CONFIG_NET_FOU_IP_TUNNELS=y
    CONFIG_INET_ESP=y
    CONFIG_SYN_COOKIES=y
    # CONFIG_INET_XFRM_MODE_TUNNEL is not set
    # CONFIG_INET_XFRM_MODE_BEET is not set
    # CONFIG_INET_LRO is not set
    # CONFIG_INET_DIAG is not set
    # CONFIG_INET6_XFRM_MODE_TRANSPORT is not set
    # CONFIG_INET6_XFRM_MODE_TUNNEL is not set
    # CONFIG_INET6_XFRM_MODE_BEET is not set
    # CONFIG_IPV6_SIT is not set
    # CONFIG_ANDROID_PARANOID_NETWORK is not set
    CONFIG_TCP_CONG_ADVANCED=y
    CONFIG_TCP_MD5SIG=y
    CONFIG_IPV6_ROUTER_PREF=y
    CONFIG_IPV6_ROUTE_INFO=y
    CONFIG_IPV6_SIT_6RD=y
    CONFIG_IPV6_MULTIPLE_TABLES=y
    CONFIG_IPV6_SUBTREES=y
    CONFIG_IPV6_MROUTE=y
    CONFIG_IPV6_MROUTE_MULTIPLE_TABLES=y
    CONFIG_IPV6_PIMSM_V2=y
    CONFIG_NETLABEL=y
    CONFIG_NETWORK_SECMARK=y
    CONFIG_NETFILTER=y
    CONFIG_NF_CONNTRACK=y
    CONFIG_NF_CONNTRACK_SECMARK=y
    CONFIG_NF_CONNTRACK_ZONES=y
    # CONFIG_NF_CONNTRACK_PROCFS is not set
    CONFIG_NF_CONNTRACK_EVENTS=y
    CONFIG_NF_CONNTRACK_TIMEOUT=y
    CONFIG_NF_CONNTRACK_TIMESTAMP=y
    CONFIG_NF_CONNTRACK_FTP=y
    CONFIG_NF_CONNTRACK_TFTP=y
    CONFIG_NETFILTER_NETLINK_GLUE_CT=y
    CONFIG_NETFILTER_XT_MATCH_ADDRTYPE=y
    CONFIG_NETFILTER_XT_MATCH_CONNTRACK=y
    CONFIG_NETFILTER_XT_MATCH_IPVS=y
    CONFIG_IP_VS=y
    CONFIG_IP_VS_IPV6=y
    CONFIG_BRIDGE_NETFILTER=y
    CONFIG_IP_VS_PROTO_TCP=y
    CONFIG_IP_VS_PROTO_UDP=y
    CONFIG_IP_VS_PROTO_ESP=y
    CONFIG_IP_VS_PROTO_AH=y
    CONFIG_IP_VS_PROTO_SCTP=y
    CONFIG_IP_VS_RR=y
    CONFIG_IP_VS_NFCT=y
    CONFIG_NF_CONNTRACK_IPV4=y
    CONFIG_IP_NF_IPTABLES=y
    CONFIG_IP_NF_FILTER=y
    CONFIG_IP_NF_NAT=y
    CONFIG_IP_NF_TARGET_MASQUERADE=y
    CONFIG_IP_NF_TARGET_REDIRECT=y
    # CONFIG_IP_DCCP_CCID3 is not set
    CONFIG_SCTP_DEFAULT_COOKIE_HMAC_SHA1=y
    CONFIG_SCTP_COOKIE_HMAC_MD5=y
    CONFIG_L2TP_V3=y
    CONFIG_BRIDGE=y
    CONFIG_BRIDGE_VLAN_FILTERING=y
    CONFIG_VLAN_8021Q_GVRP=y
    CONFIG_VLAN_8021Q_MVRP=y
    CONFIG_IPDDP_ENCAP=y
    CONFIG_IEEE802154_NL802154_EXPERIMENTAL=y
    CONFIG_NET_SCHED=y
    CONFIG_CLS_U32_MARK=y
    CONFIG_NET_EMATCH=y
    CONFIG_NET_CLS_ACT=y
    CONFIG_GACT_PROB=y
    CONFIG_DCB=y
    CONFIG_BATMAN_ADV_DAT=y
    CONFIG_BATMAN_ADV_NC=y
    CONFIG_BATMAN_ADV_MCAST=y
    CONFIG_NET_L3_MASTER_DEV=y
    CONFIG_CGROUP_NET_PRIO=y
    CONFIG_BPF_JIT=y
    CONFIG_BT=y
    CONFIG_BT_RFCOMM=y
    CONFIG_BT_HIDP=y
    CONFIG_BT_HCIBTUSB=y
    CONFIG_BT_HCIUART=y
    CONFIG_BT_HCIUART_ATH3K=y
    CONFIG_BT_HCIUART_LL=y
    CONFIG_BT_HCIBFUSB=y
    CONFIG_BT_HCIVHCI=y
    CONFIG_BT_MRVL=y
    CONFIG_BT_MRVL_SDIO=y
    CONFIG_NL80211_TESTMODE=y
    CONFIG_CFG80211_DEBUGFS=y
    CONFIG_CFG80211_WEXT=y
    CONFIG_MAC80211_LEDS=y
    CONFIG_MAC80211_DEBUGFS=y
    CONFIG_MAC80211_DEBUG_MENU=y
    CONFIG_MAC80211_VERBOSE_DEBUG=y
    CONFIG_RFKILL=y
    CONFIG_NFC=y
    CONFIG_NFC_DIGITAL=y
    CONFIG_NFC_DL1825=y
    CONFIG_DEVTMPFS=y
    CONFIG_DEVTMPFS_MOUNT=y
    CONFIG_EXTRA_FIRMWARE="rtl8723du_config rtl8723du_fw"
    CONFIG_DEBUG_DEVRES=y
    CONFIG_CONNECTOR=y
    CONFIG_MTD=y
    CONFIG_MTD_M25P80=y
    CONFIG_MTD_SPI_NOR=y
    CONFIG_ZRAM=y
    CONFIG_BLK_DEV_LOOP=y
    CONFIG_BLK_DEV_RAM=y
    CONFIG_BLK_DEV_RAM_COUNT=1
    CONFIG_BLK_DEV_NVME=y
    CONFIG_ROCKCHIP_SCR=y
    CONFIG_SRAM=y
    CONFIG_DS18B20=y
    CONFIG_BLK_DEV_SD=y
    CONFIG_BLK_DEV_SR=y
    CONFIG_CHR_DEV_SG=y
    CONFIG_SCSI_SCAN_ASYNC=y
    CONFIG_SCSI_SPI_ATTRS=y
    CONFIG_ATA=y
    CONFIG_SATA_AHCI=y
    CONFIG_SATA_AHCI_PLATFORM=y
    CONFIG_AHCI_CEVA=y
    CONFIG_ATA_GENERIC=y
    CONFIG_MD=y
    CONFIG_BLK_DEV_DM=y
    CONFIG_DM_THIN_PROVISIONING=y
    CONFIG_NETDEVICES=y
    CONFIG_DUMMY=y
    CONFIG_MACVLAN=y
    CONFIG_IPVLAN=y
    CONFIG_VXLAN=y
    CONFIG_TUN=y
    CONFIG_VETH=y
    # CONFIG_NET_VENDOR_3COM is not set
    # CONFIG_NET_VENDOR_ADAPTEC is not set
    # CONFIG_NET_VENDOR_AGERE is not set
    # CONFIG_NET_VENDOR_ALTEON is not set
    # CONFIG_NET_VENDOR_AMD is not set
    # CONFIG_NET_VENDOR_ARC is not set
    # CONFIG_NET_VENDOR_ATHEROS is not set
    # CONFIG_NET_CADENCE is not set
    # CONFIG_NET_VENDOR_BROADCOM is not set
    # CONFIG_NET_VENDOR_BROCADE is not set
    # CONFIG_NET_VENDOR_CAVIUM is not set
    # CONFIG_NET_VENDOR_CHELSIO is not set
    # CONFIG_NET_VENDOR_CISCO is not set
    # CONFIG_NET_VENDOR_DEC is not set
    # CONFIG_NET_VENDOR_DLINK is not set
    # CONFIG_NET_VENDOR_EMULEX is not set
    # CONFIG_NET_VENDOR_EZCHIP is not set
    # CONFIG_NET_VENDOR_EXAR is not set
    # CONFIG_NET_VENDOR_HISILICON is not set
    # CONFIG_NET_VENDOR_HP is not set
    # CONFIG_NET_VENDOR_INTEL is not set
    # CONFIG_NET_VENDOR_MARVELL is not set
    # CONFIG_NET_VENDOR_MELLANOX is not set
    # CONFIG_NET_VENDOR_MICREL is not set
    # CONFIG_NET_VENDOR_MICROCHIP is not set
    # CONFIG_NET_VENDOR_MYRI is not set
    # CONFIG_NET_VENDOR_NATSEMI is not set
    # CONFIG_NET_VENDOR_NVIDIA is not set
    # CONFIG_NET_VENDOR_OKI is not set
    # CONFIG_NET_PACKET_ENGINE is not set
    # CONFIG_NET_VENDOR_QLOGIC is not set
    # CONFIG_NET_VENDOR_QUALCOMM is not set
    # CONFIG_NET_VENDOR_REALTEK is not set
    # CONFIG_NET_VENDOR_RENESAS is not set
    # CONFIG_NET_VENDOR_RDC is not set
    # CONFIG_NET_VENDOR_ROCKER is not set
    # CONFIG_NET_VENDOR_SAMSUNG is not set
    # CONFIG_NET_VENDOR_SEEQ is not set
    # CONFIG_NET_VENDOR_SILAN is not set
    # CONFIG_NET_VENDOR_SIS is not set
    # CONFIG_NET_VENDOR_SMSC is not set
    CONFIG_STMMAC_ETH=y
    # CONFIG_NET_VENDOR_SUN is not set
    # CONFIG_NET_VENDOR_SYNOPSYS is not set
    # CONFIG_NET_VENDOR_TEHUTI is not set
    # CONFIG_NET_VENDOR_TI is not set
    # CONFIG_NET_VENDOR_VIA is not set
    # CONFIG_NET_VENDOR_WIZNET is not set
    CONFIG_ROCKCHIP_PHY=y
    CONFIG_USB_RTL8150=y
    CONFIG_USB_RTL8152=y
    CONFIG_USB_NET_CDC_MBIM=y
    # CONFIG_USB_NET_NET1080 is not set
    # CONFIG_USB_NET_CDC_SUBSET is not set
    # CONFIG_USB_NET_ZAURUS is not set
    CONFIG_USB_NET_QMI_WWAN=y
    CONFIG_LIBERTAS_THINFIRM=y
    CONFIG_USB_NET_RNDIS_WLAN=y
    CONFIG_WL_MEDIATEK=y
    CONFIG_MT7601U=y
    CONFIG_RTL8192CU=y
    CONFIG_WL_ROCKCHIP=y
    CONFIG_WIFI_LOAD_DRIVER_WHEN_KERNEL_BOOTUP=y
    CONFIG_AP6XXX=y
    CONFIG_RTL8723DU=y
    CONFIG_MWIFIEX=y
    CONFIG_MWIFIEX_SDIO=y
    CONFIG_INPUT_FF_MEMLESS=y
    # CONFIG_INPUT_MOUSEDEV is not set
    CONFIG_INPUT_EVDEV=y
    CONFIG_KEYBOARD_ADC=y
    # CONFIG_KEYBOARD_ATKBD is not set
    CONFIG_KEYBOARD_GPIO=y
    CONFIG_KEYBOARD_GPIO_POLLED=y
    CONFIG_KEYBOARD_ROCKCHIP=y
    CONFIG_KEYBOARD_CROS_EC=y
    # CONFIG_MOUSE_PS2 is not set
    CONFIG_MOUSE_CYAPA=y
    CONFIG_MOUSE_ELAN_I2C=y
    CONFIG_INPUT_TOUCHSCREEN=y
    CONFIG_TOUCHSCREEN_ATMEL_MXT=y
    CONFIG_TOUCHSCREEN_GSLX680_FIREFLY=y
    CONFIG_TOUCHSCREEN_GSL3673=y
    CONFIG_TOUCHSCREEN_GT9XX=y
    CONFIG_TOUCHSCREEN_ELAN=y
    CONFIG_TOUCHSCREEN_USB_COMPOSITE=y
    CONFIG_TOUCHSCREEN_GT1X=y
    CONFIG_TOUCHSCREEN_HX83102=y
    CONFIG_ROCKCHIP_REMOTECTL=y
    CONFIG_ROCKCHIP_REMOTECTL_PWM=y
    CONFIG_RK_IR_NO_DEEP_SLEEP=y
    CONFIG_SENSOR_DEVICE=y
    CONFIG_GS_MC3230=y
    CONFIG_INPUT_MISC=y
    CONFIG_INPUT_RK8XX_PWRKEY=y
    CONFIG_INPUT_UINPUT=y
    CONFIG_INPUT_GPIO=y
    # CONFIG_SERIO is not set
    CONFIG_DEVPTS_MULTIPLE_INSTANCES=y
    # CONFIG_LEGACY_PTYS is not set
    # CONFIG_DEVKMEM is not set
    CONFIG_SERIAL_8250=y
    CONFIG_SERIAL_8250_CONSOLE=y
    # CONFIG_SERIAL_8250_PCI is not set
    CONFIG_SERIAL_8250_NR_UARTS=5
    CONFIG_SERIAL_8250_RUNTIME_UARTS=5
    CONFIG_SERIAL_8250_DW=y
    CONFIG_SERIAL_OF_PLATFORM=y
    CONFIG_HW_RANDOM=y
    CONFIG_HW_RANDOM_ROCKCHIP=y
    CONFIG_TCG_TPM=y
    CONFIG_TCG_TIS_I2C_INFINEON=y
    CONFIG_I2C_CHARDEV=y
    CONFIG_I2C_MUX=y
    CONFIG_I2C_RK3X=y
    CONFIG_I2C_CROS_EC_TUNNEL=y
    CONFIG_SPI=y
    CONFIG_SPI_BITBANG=y
    CONFIG_SPI_ROCKCHIP=y
    CONFIG_SPI_SPIDEV=y
    CONFIG_SPI_WK2XXX=y
    CONFIG_DEBUG_GPIO=y
    CONFIG_GPIO_SYSFS=y
    CONFIG_GPIO_GENERIC_PLATFORM=y
    CONFIG_GPIO_PCA953X=y
    CONFIG_GPIO_RK8XX=y
    CONFIG_GPIO_WIEGAND_SEND=y
    CONFIG_GPIO_WIEGAND_RECEIVE=y
    CONFIG_GPIO_RADAR=y
    CONFIG_GPIO_ADB_SELECT=y
    CONFIG_BATTERY_SBS=y
    CONFIG_CHARGER_GPIO=y
    CONFIG_CHARGER_BQ24735=y
    CONFIG_BATTERY_CW2015=y
    CONFIG_BATTERY_RK817=y
    CONFIG_CHARGER_RK817=y
    CONFIG_POWER_RESET_GPIO=y
    CONFIG_POWER_RESET_GPIO_RESTART=y
    CONFIG_SYSCON_REBOOT_MODE=y
    CONFIG_POWER_AVS=y
    CONFIG_ROCKCHIP_IODOMAIN=y
    CONFIG_SENSORS_NTC_THERMISTOR=y
    CONFIG_THERMAL=y
    CONFIG_THERMAL_WRITABLE_TRIPS=y
    CONFIG_THERMAL_DEFAULT_GOV_POWER_ALLOCATOR=y
    CONFIG_THERMAL_GOV_FAIR_SHARE=y
    CONFIG_THERMAL_GOV_STEP_WISE=y
    CONFIG_CPU_THERMAL=y
    CONFIG_DEVFREQ_THERMAL=y
    CONFIG_ROCKCHIP_THERMAL=y
    CONFIG_WATCHDOG=y
    CONFIG_DW_WATCHDOG=y
    CONFIG_SOFT_WATCHDOG=n
    CONFIG_WATCHDOG_CORE=y
    CONFIG_MFD_CROS_EC=y
    CONFIG_MFD_CROS_EC_SPI=y
    CONFIG_MFD_RK808=y
    CONFIG_MFD_TPS6586X=y
    CONFIG_FUSB_30X=y
    CONFIG_REGULATOR=y
    CONFIG_REGULATOR_DEBUG=y
    CONFIG_REGULATOR_FIXED_VOLTAGE=y
    CONFIG_REGULATOR_ACT8865=y
    CONFIG_REGULATOR_FAN53555=y
    CONFIG_REGULATOR_GPIO=y
    CONFIG_REGULATOR_LP8752=y
    CONFIG_REGULATOR_MP8865=y
    CONFIG_REGULATOR_MP8859=y
    CONFIG_REGULATOR_PWM=y
    CONFIG_REGULATOR_RK808=y
    CONFIG_REGULATOR_RK818=y
    CONFIG_REGULATOR_TPS6586X=y
    CONFIG_REGULATOR_XZ3216=y
    CONFIG_MEDIA_SUPPORT=y
    CONFIG_MEDIA_CAMERA_SUPPORT=y
    CONFIG_MEDIA_RC_SUPPORT=y
    CONFIG_MEDIA_CEC_SUPPORT=y
    CONFIG_MEDIA_CONTROLLER=y
    CONFIG_VIDEO_V4L2_SUBDEV_API=y
    # CONFIG_IR_RC5_DECODER is not set
    # CONFIG_IR_RC6_DECODER is not set
    # CONFIG_IR_JVC_DECODER is not set
    # CONFIG_IR_SONY_DECODER is not set
    # CONFIG_IR_SANYO_DECODER is not set
    # CONFIG_IR_SHARP_DECODER is not set
    # CONFIG_IR_MCE_KBD_DECODER is not set
    # CONFIG_IR_XMP_DECODER is not set
    CONFIG_MEDIA_USB_SUPPORT=y
    CONFIG_USB_VIDEO_CLASS=y
    # CONFIG_USB_VIDEO_CLASS_INPUT_EVDEV is not set
    # CONFIG_USB_GSPCA is not set
    CONFIG_NPU_USB_ACM=y
    CONFIG_V4L_PLATFORM_DRIVERS=y
    CONFIG_SOC_CAMERA=y
    CONFIG_VIDEO_ROCKCHIP_ISP1=y
    CONFIG_VIDEO_ROCKCHIP_USBACM_CONTROL=y
    CONFIG_V4L_MEM2MEM_DRIVERS=y
    CONFIG_VIDEO_ROCKCHIP_RGA=y
    # CONFIG_MEDIA_SUBDRV_AUTOSELECT is not set
    # CONFIG_VIDEO_IR_I2C is not set
    CONFIG_VIDEO_TC35874X=y
    CONFIG_VIDEO_IMX327=y
    CONFIG_VIDEO_OV4689=y
    CONFIG_VIDEO_OV13850=y
    CONFIG_VIDEO_VM149C=y
    CONFIG_VIDEO_XC7022=y
    CONFIG_VIDEO_XC7160=y
    # CONFIG_DVB_AU8522_V4L is not set
    # CONFIG_DVB_TUNER_DIB0070 is not set
    # CONFIG_DVB_TUNER_DIB0090 is not set
    # CONFIG_VGA_ARB is not set
    CONFIG_DRM=y
    CONFIG_DRM_LOAD_EDID_FIRMWARE=y
    CONFIG_DRM_DMA_SYNC=y
    CONFIG_DRM_ROCKCHIP=y
    CONFIG_ROCKCHIP_DRM_DEBUG=y
    CONFIG_ROCKCHIP_CDN_DP=y
    CONFIG_ROCKCHIP_DW_HDMI=y
    CONFIG_ROCKCHIP_DW_MIPI_DSI=y
    CONFIG_ROCKCHIP_ANALOGIX_DP=y
    CONFIG_ROCKCHIP_INNO_HDMI=y
    CONFIG_ROCKCHIP_LVDS=y
    CONFIG_ROCKCHIP_DRM_TVE=y
    CONFIG_ROCKCHIP_RGB=y
    CONFIG_DRM_PANEL_SIMPLE=y
    CONFIG_DRM_DW_HDMI_I2S_AUDIO=y
    CONFIG_DRM_DW_HDMI_CEC=y
    CONFIG_MALI400=y
    CONFIG_MALI450=y
    # CONFIG_MALI400_PROFILING is not set
    CONFIG_MALI_SHARED_INTERRUPTS=y
    CONFIG_MALI_DT=y
    CONFIG_MALI_DEVFREQ=y
    CONFIG_MALI_MIDGARD=y
    CONFIG_MALI_EXPERT=y
    CONFIG_MALI_PLATFORM_THIRDPARTY=y
    CONFIG_MALI_PLATFORM_THIRDPARTY_NAME="rk"
    CONFIG_MALI_DEBUG=y
    CONFIG_MALI_PWRSOFT_765=y
    CONFIG_MALI_BIFROST_FOR_LINUX=y
    CONFIG_BACKLIGHT_LCD_SUPPORT=y
    # CONFIG_LCD_CLASS_DEVICE is not set
    CONFIG_BACKLIGHT_CLASS_DEVICE=y
    CONFIG_BACKLIGHT_PWM=y
    CONFIG_ROCKCHIP_RGA2=y
    CONFIG_RK_VCODEC=y
    CONFIG_IEP=y
    CONFIG_IEP_MMU=y
    CONFIG_ROCKCHIP_MPP_SERVICE=y
    CONFIG_ROCKCHIP_MPP_DEVICE=y
    CONFIG_FRAMEBUFFER_CONSOLE=y
    CONFIG_SOUND=y
    CONFIG_SND=y
    CONFIG_SND_SEQUENCER=y
    CONFIG_SND_SEQ_DUMMY=y
    CONFIG_SND_HRTIMER=y
    CONFIG_SND_DYNAMIC_MINORS=y
    # CONFIG_SND_SUPPORT_OLD_API is not set
    # CONFIG_SND_PCI is not set
    # CONFIG_SND_SPI is not set
    CONFIG_SND_USB_AUDIO=y
    CONFIG_SND_SOC=y
    CONFIG_SND_SOC_ROCKCHIP=y
    CONFIG_SND_SOC_ROCKCHIP_SPDIF=y
    CONFIG_SND_SOC_ROCKCHIP_HDMI_DP=y
    CONFIG_SND_SOC_ROCKCHIP_MAX98090=y
    CONFIG_SND_SOC_ROCKCHIP_MULTICODECS=y
    CONFIG_SND_SOC_ROCKCHIP_RT5645=y
    CONFIG_SND_SOC_ROCKCHIP_CDNDP=y
    CONFIG_SND_SOC_ES8316=y
    CONFIG_SND_SOC_ES8323=y
    CONFIG_SND_SOC_RK3328=y
    CONFIG_SND_SOC_RK817=y
    CONFIG_SND_SOC_RT5616=y
    CONFIG_SND_SOC_RT5640=y
    CONFIG_SND_SOC_RT5651=y
    CONFIG_SND_SOC_SPDIF=y
    CONFIG_SND_SIMPLE_CARD=y
    CONFIG_HID_BATTERY_STRENGTH=y
    CONFIG_HIDRAW=y
    CONFIG_UHID=y
    CONFIG_HID_KENSINGTON=y
    CONFIG_HID_MULTITOUCH=y
    CONFIG_USB_HIDDEV=y
    CONFIG_I2C_HID=y
    CONFIG_USB_ANNOUNCE_NEW_DEVICES=y
    # CONFIG_USB_DEFAULT_PERSIST is not set
    CONFIG_USB_OTG=y
    CONFIG_USB_MON=y
    CONFIG_USB_XHCI_HCD=y
    CONFIG_USB_EHCI_HCD=y
    CONFIG_USB_EHCI_ROOT_HUB_TT=y
    CONFIG_USB_EHCI_HCD_PLATFORM=y
    CONFIG_USB_OHCI_HCD=y
    # CONFIG_USB_OHCI_HCD_PCI is not set
    CONFIG_USB_OHCI_HCD_PLATFORM=y
    CONFIG_USB_ACM=y
    CONFIG_USB_STORAGE=y
    CONFIG_USB_UAS=y
    CONFIG_USB_DWC3=y
    # CONFIG_USB_DWC3_PCI is not set
    CONFIG_USB_DWC2=y
    CONFIG_USB_SERIAL=y
    CONFIG_USB_SERIAL_GENERIC=y
    CONFIG_USB_SERIAL_CH341=y
    CONFIG_USB_SERIAL_CP210X=y
    CONFIG_USB_SERIAL_FTDI_SIO=y
    CONFIG_USB_SERIAL_KEYSPAN=y
    CONFIG_USB_SERIAL_PL2303=y
    CONFIG_USB_SERIAL_OTI6858=y
    CONFIG_USB_SERIAL_QUALCOMM=y
    CONFIG_USB_SERIAL_SIERRAWIRELESS=y
    CONFIG_USB_SERIAL_OPTION=y
    CONFIG_USB_GADGET=y
    CONFIG_USB_GADGET_DEBUG_FILES=y
    CONFIG_USB_GADGET_VBUS_DRAW=500
    CONFIG_USB_CONFIGFS=y
    CONFIG_USB_CONFIGFS_ACM=y
    CONFIG_USB_CONFIGFS_RNDIS=y
    CONFIG_USB_CONFIGFS_MASS_STORAGE=y
    CONFIG_USB_CONFIGFS_F_FS=y
    CONFIG_USB_CONFIGFS_F_MTP=y
    CONFIG_USB_CONFIGFS_UEVENT=y
    CONFIG_USB_CONFIGFS_F_UAC1=y
    CONFIG_USB_CONFIGFS_F_UAC2=y
    CONFIG_USB_CONFIGFS_F_HID=y
    CONFIG_USB_CONFIGFS_F_UVC=y
    CONFIG_MMC=y
    CONFIG_MMC_BLOCK_MINORS=32
    CONFIG_MMC_TEST=y
    CONFIG_MMC_SDHCI=y
    CONFIG_MMC_SDHCI_PLTFM=y
    CONFIG_MMC_SDHCI_OF_ARASAN=y
    CONFIG_MMC_DW=y
    CONFIG_MMC_DW_ROCKCHIP=y
    CONFIG_NEW_LEDS=y
    CONFIG_LEDS_CLASS=y
    CONFIG_LEDS_GPIO=y
    CONFIG_LEDS_IS31FL32XX=y
    CONFIG_SWITCH=y
    CONFIG_RTC_CLASS=y
    CONFIG_RTC_DRV_HYM8563=y
    CONFIG_RTC_DRV_RK808=y
    CONFIG_DMADEVICES=y
    CONFIG_PL330_DMA=y
    CONFIG_STAGING=y
    CONFIG_INV_MPU_IIO=y
    CONFIG_SENSORS_ISL29018=y
    CONFIG_TSL2583=y
    # CONFIG_ANDROID_TIMED_OUTPUT is not set
    CONFIG_FIQ_DEBUGGER=y
    CONFIG_FIQ_DEBUGGER_NO_SLEEP=y
    CONFIG_FIQ_DEBUGGER_CONSOLE=y
    CONFIG_FIQ_DEBUGGER_CONSOLE_DEFAULT_ENABLE=y
    CONFIG_COMMON_CLK_RK808=y
    CONFIG_MAILBOX=y
    CONFIG_ROCKCHIP_IOMMU=y
    CONFIG_RK_IOMMU=y
    CONFIG_RK_IOVMM=y
    CONFIG_ROCKCHIP_PM_DOMAINS=y
    CONFIG_ROCKCHIP_PVTM=y
    CONFIG_ROCKCHIP_SUSPEND_MODE=y
    CONFIG_PM_DEVFREQ=y
    CONFIG_DEVFREQ_GOV_PERFORMANCE=y
    CONFIG_DEVFREQ_GOV_POWERSAVE=y
    CONFIG_DEVFREQ_GOV_USERSPACE=y
    CONFIG_ARM_ROCKCHIP_DMC_DEVFREQ=y
    CONFIG_PM_DEVFREQ_EVENT=y
    CONFIG_MEMORY=y
    CONFIG_IIO=y
    CONFIG_IIO_BUFFER=y
    CONFIG_IIO_KFIFO_BUF=y
    CONFIG_IIO_TRIGGER=y
    CONFIG_ROCKCHIP_SARADC=y
    CONFIG_SENSORS_TSL2563=y
    CONFIG_IIO_SYSFS_TRIGGER=y
    CONFIG_PWM=y
    CONFIG_PWM_ROCKCHIP=y
    CONFIG_PHY_ROCKCHIP_USB=y
    CONFIG_PHY_ROCKCHIP_INNO_USB2=y
    CONFIG_PHY_ROCKCHIP_INNO_USB3=y
    CONFIG_PHY_ROCKCHIP_EMMC=y
    CONFIG_PHY_ROCKCHIP_DP=y
    CONFIG_PHY_ROCKCHIP_INNO_MIPI_DPHY=y
    CONFIG_PHY_ROCKCHIP_INNO_HDMI_PHY=y
    CONFIG_PHY_ROCKCHIP_INNO_VIDEO_COMBO_PHY=y
    CONFIG_PHY_ROCKCHIP_TYPEC=y
    CONFIG_PHY_ROCKCHIP_PCIE=y
    CONFIG_ANDROID=y
    CONFIG_NVMEM=y
    CONFIG_ROCKCHIP_EFUSE=y
    CONFIG_RK_HEADSET=y
    CONFIG_ROCKCHIP_SIP=y
    # CONFIG_ACPI is not set
    CONFIG_EXT4_FS=y
    CONFIG_EXT4_FS_POSIX_ACL=y
    CONFIG_EXT4_FS_SECURITY=y
    CONFIG_XFS_FS=y
    CONFIG_BTRFS_FS=y
    CONFIG_BTRFS_FS_POSIX_ACL=y
    # CONFIG_DNOTIFY is not set
    CONFIG_AUTOFS4_FS=y
    CONFIG_FUSE_FS=y
    CONFIG_OVERLAY_FS=y
    CONFIG_ISO9660_FS=y
    CONFIG_JOLIET=y
    CONFIG_ZISOFS=y
    CONFIG_VFAT_FS=y
    CONFIG_FAT_DEFAULT_CODEPAGE=936
    CONFIG_FAT_DEFAULT_IOCHARSET="utf8"
    CONFIG_NTFS_FS=y
    CONFIG_TMPFS=y
    CONFIG_TMPFS_POSIX_ACL=y
    CONFIG_HUGETLBFS=y
    CONFIG_CONFIGFS_FS=y
    CONFIG_SQUASHFS=y
    CONFIG_SQUASHFS_LZ4=y
    CONFIG_SQUASHFS_LZO=y
    CONFIG_SQUASHFS_XZ=y
    CONFIG_PSTORE=y
    CONFIG_PSTORE_CONSOLE=y
    CONFIG_PSTORE_RAM=y
    CONFIG_NFS_FS=y
    CONFIG_NFS_V3_ACL=y
    CONFIG_NFS_V4=y
    CONFIG_NFS_SWAP=y
    CONFIG_NFSD=y
    CONFIG_NFSD_V4=y
    CONFIG_NLS_DEFAULT="utf8"
    CONFIG_NLS_CODEPAGE_437=y
    CONFIG_NLS_CODEPAGE_936=y
    CONFIG_NLS_ASCII=y
    CONFIG_NLS_ISO8859_1=y
    CONFIG_NLS_UTF8=y
    CONFIG_VIRTUALIZATION=y
    CONFIG_KVM=y
    CONFIG_VHOST_NET=y
    CONFIG_VHOST_CROSS_ENDIAN_LEGACY=y
    CONFIG_PRINTK_TIME=y
    CONFIG_DYNAMIC_DEBUG=y
    CONFIG_DEBUG_INFO=y
    CONFIG_MAGIC_SYSRQ=y
    CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE=0
    CONFIG_LOCKUP_DETECTOR=y
    CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
    CONFIG_BOOTPARAM_HUNG_TASK_PANIC=y
    CONFIG_SCHEDSTATS=y
    CONFIG_TIMER_STATS=y
    CONFIG_DEBUG_SPINLOCK=y
    CONFIG_DEBUG_CREDENTIALS=y
    CONFIG_RCU_CPU_STALL_TIMEOUT=60
    CONFIG_FUNCTION_TRACER=y
    CONFIG_BLK_DEV_IO_TRACE=y
    CONFIG_LKDTM=y
    CONFIG_STRICT_DEVMEM=y
    CONFIG_DEBUG_SET_MODULE_RONX=y
    CONFIG_SECURITY=y
    CONFIG_CRYPTO_AUTHENC=y
    CONFIG_CRYPTO_ECHAINIV=y
    CONFIG_CRYPTO_CBC=y
    CONFIG_CRYPTO_SHA1=y
    CONFIG_CRYPTO_SHA512=y
    CONFIG_CRYPTO_DES=y
    CONFIG_CRYPTO_TWOFISH=y
    CONFIG_CRYPTO_ANSI_CPRNG=y
    CONFIG_CRYPTO_USER_API_HASH=y
    CONFIG_CRYPTO_USER_API_SKCIPHER=y
    CONFIG_ASYMMETRIC_KEY_TYPE=y
    CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE=y
    CONFIG_X509_CERTIFICATE_PARSER=y
    CONFIG_PKCS7_MESSAGE_PARSER=y
    CONFIG_SYSTEM_TRUSTED_KEYRING=y
    CONFIG_ARM64_CRYPTO=y
    CONFIG_CRYPTO_SHA1_ARM64_CE=y
    CONFIG_CRYPTO_SHA2_ARM64_CE=y
    CONFIG_CRYPTO_GHASH_ARM64_CE=y
    CONFIG_CRYPTO_AES_ARM64_CE_CCM=y
    CONFIG_CRYPTO_AES_ARM64_CE_BLK=y
    CONFIG_CRC_T10DIF=y
    CONFIG_CRC7=y
    # CONFIG_XZ_DEC_X86 is not set
    # CONFIG_XZ_DEC_POWERPC is not set
    # CONFIG_XZ_DEC_IA64 is not set
    # CONFIG_XZ_DEC_SPARC is not set

修改成我的配置

CONFIG_WATCHDOG=y
    CONFIG_DW_WATCHDOG=y #build-in
    CONFIG_SOFT_WATCHDOG=n #不需要
    CONFIG_WATCHDOG_CORE=y

或者

CONFIG_WATCHDOG=y
    CONFIG_DW_WATCHDOG=m #module
    CONFIG_SOFT_WATCHDOG=n #不需要
    CONFIG_WATCHDOG_CORE=y

CONFIG\_SOFT\_WATCHDOG选n就行了，就是不编译，因为有了硬件watchdog，软件watchdog其实就没有那么必要了，可以理解为软件watchdog是硬件watchdog的一个补充。

`设备树`  
kernel/arch/arm64/boot/dts/rockchip/rk3399-firefly-aioc.dtsi  
在这个设备里找到`&wdt`并将status设置为okay，默认是disable的

&wdt {
        
            status = "okay";
    };

`切记保存下`

### 2.开始编译 ###

回到源代码主目录然后进入kernel的目录执行make clean清除以前的编译缓存。然后回到主目录执行

./build.sh aio-3399c-ubuntu.mk

我的是非AI版的，如果你是AI版就执行:

./build.sh aio-3399c-ai-ubuntu.mk

上面的shell是指定编译哪一个board，因为firefly的源代码支持的board种类众多，需要人工指定下。  
接下来执行内核编译任务：

./build.sh kernel

如果指定kernel就是只编译内核，我就是只编译内核的，如果你想完整编译就执行：

./build.sh

`整个过程不需要sudo权限`

### 3.安装内核 ###

我们不用完整刷机，可以单刷内核，方法也很简单，我们只需要将kernel目录的boot.img复制到设备上然后通过dd拷贝到指定分区就行了，这个地方操作很危险，如果你准备采用我这种方式的话请`仔仔细细`往下看，否则可能`资料全失，欲哭无泪！！！操作前切记备份资料!!`

1.  查看分区表  
    回到源代码主目录找到rockdev的目录里的paramter.txt，这个文件是一个软链，不过我们并不关心它是啥，我们只看它的内容。每个设备，每个人环境都可能不一样，这个文件的内容也可能不一样，但是大体结构是一样的。

FIRMWARE_VER: 8.1
    MACHINE_MODEL: RK3399
    MACHINE_ID: 007
    MANUFACTURER: RK3399
    MAGIC: 0x5041524B
    ATAG: 0x00200800
    MACHINE: 3399
    CHECK_MASK: 0x80
    PWR_HLD: 0,0,A,0,1
    TYPE: GPT
    CMDLINE: mtdparts=rk29xxnand:0x00002000@0x00004000(uboot),0x00002000@0x00006000(trust),0x00002000@0x00008000(misc),0x00020000@0x0000a000(boot),0x00020000@0x0002a000(recovery),0x00010000@0x0004a000(backup),0x00600000@0x0005a000(rootfs),-@0x0065a000(userdata:grow)
    uuid:rootfs=614e0000-0000-4b53-8000-1d28000054a9

找到`0x00020000@0x0000a000(boot)`这个配置，前面的`0x00020000`是emmc分区的开始位置，这个位置一定不能和前面的分区重合，否则会覆盖并破坏数据，导致系统无法启动，保持默认就好。后面的`0x0000a000`是从起始位置扩展的空间大小。`注意：这个值是sectors，不是B或KB这种单位`，sector怎么看可以到设备上看，执行sudo fdisk -l可以看到分区详细信息：

Disk /dev/mmcblk0: 14.6 GiB, 15634268160 bytes, 30535680 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disklabel type: gpt
    Disk identifier: FB330000-0000-4A61-8000-06380000252A
    
    Device           Start      End  Sectors  Size Type
    /dev/mmcblk0p1   16384    24575     8192    4M unknown
    /dev/mmcblk0p2   24576    32767     8192    4M unknown
    /dev/mmcblk0p3   32768    40959     8192    4M unknown
    /dev/mmcblk0p4   40960   172031   131072   64M unknown
    /dev/mmcblk0p5  172032   303103   131072   64M unknown
    /dev/mmcblk0p6  303104   368639    65536   32M unknown
    /dev/mmcblk0p7  368640  4325375  3956736  1.9G unknown
    /dev/mmcblk0p8 4325376 30535646 26210271 12.5G unknown

注意这句`Units: sectors of 1 * 512 = 512 bytes`，说明文件系统的每一个sector占512B，所以上面的boot实际分区大小是`10*16^3*512 字节也就是20MB`，但事实是我们打出来的boot.img大小是33MB左右，所以这个分区是不是有问题？这里先卖个关子，留在后面解释。

1.  确认分区位置  
    从paramter.txt可以看出来我们有8个分区，而boot是第4个分区，也就是上面的

/dev/mmcblk0p4   40960   172031   131072   64M unknown

好，分区已经确认，接下来复写内核。

1.  更新内核

将boot.img复制到需要更新的设备的home目录下，确保设备上至少有大于boot.img的内存空间。执行以下命令：

sudo dd if=boot.img of=/dev/mmcblk0p4

等待写入完成，如果没报错就说明成功了，如果报错了就说明完蛋了，只要你重新启动设备就陷入无限循环了。这个时候只能完整刷机了，运气好的刷入旧的内核可以解决，前提是你的内核不能大于64M，一旦超过这个数可能覆盖后一个分区，导致不可逆的损坏，只能完整镜像抢救了！！！

不出以外你的设备重启进入系统，执行ls /dev会出现watchdog这个字符设备，测试代码如下:

watchdog.c

#include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <sys/types.h>
    #include <sys/stat.h>
    #include <unistd.h>
    #include <fcntl.h>
    #include <sys/ioctl.h>
    #include <errno.h>
    #include <sys/time.h>
    #include <unistd.h>
    #include <time.h>
    #include <getopt.h>
    #include <sys/signal.h>
    #include <termios.h>
    
    struct watchdog_info{
        
        unsigned int options;   //options the card/driver supprots 19
        unsigned int firmware_version;  //firmcard version of the card
        unsigned char identity[32];     //identity of the board 21
     };
    
    #define WATCHDOG_IOCTL_BASE 'W'
    #define WDIOC_GETSUPPORT _IOR(WATCHDOG_IOCTL_BASE, 0, struct watchdog_info)
    #define WDIOC_SETTIMEOUT _IOWR(WATCHDOG_IOCTL_BASE, 6, int)
    #define WDIOC_GETTIMEOUT _IOR(WATCHDOG_IOCTL_BASE, 7, int) //27
    #define WDIOS_DISABLECARD 0x0001
    #define WDIOS_ENABLECARD 0x0002
    #define WDIOC_SETOPTIONS _IOR(WATCHDOG_IOCTL_BASE, 4, int)
    #define WDIOC_KEEPALIVE _IOR(WATCHDOG_IOCTL_BASE, 5, int)
    
    int Getch (void)   //无回显的从屏幕输入字符，来达到喂狗的目的
    
    {
        
    
         int ch;
         struct termios oldt, newt;   //终端设备结构体
         tcgetattr(STDIN_FILENO, &oldt);   //获得终端属性
         newt = oldt;
         newt.c_lflag &= ~(ECHO|ICANON);   //设置无回显属性
         tcsetattr(STDIN_FILENO, TCSANOW, &newt);  //设置新的终端属性
         ch = getchar();   //从键盘输入一个数据
         tcsetattr(STDIN_FILENO, TCSANOW, &oldt);  //恢复终端设备初始设置
         return ch;
    
    }
     //suspend some seconds
    int zsleep(int millisecond)
    
    {
        
         unsigned long usec;
         usec=1000*millisecond;
         usleep(usec); //usleep(1)睡眠一微秒（10E-6),这里也就是0.1s
    }
    int Init()
    {
        
         int fd;
         //open device file
         fd = open("/dev/watchdog",O_RDWR);   //打开看门狗设备
          if(fd < 0)
         {
        
             printf("device open fail\n");
             return -1;
         }
         printf("open success\n");
         return fd;
    }
    
    int main(int argc,char **argv)
    {
        
         int fd,ch;
         int i,j;
         char c;
         struct watchdog_info wi;
             if(argc != 2){
        
                     printf("Usage : ./watchdog 10\n");
                     return -1;
             }
         fd=Init();  //打开终端看门狗设备
             ioctl(fd, WDIOC_SETOPTIONS, WDIOS_ENABLECARD);
         //读板卡信息，但不常用
         ioctl(fd,WDIOC_GETSUPPORT,&wi);
         printf("options is %d,identity is %s\n",wi.options,wi.identity);
         //读看门狗溢出时间
    
         printf("put_usr return,if 0,success:%d\n",ioctl(fd,WDIOC_GETTIMEOUT,&i));
    
             printf("The old reset time is: %d\n", i);
         //关闭
          i=WDIOS_DISABLECARD;//WDIOC_SETOPTIONS=0X0001
         printf("return ENOTTY,if -1,success:%d\n",ioctl(fd,WDIOC_SETOPTIONS,&i));
         //打开
          i=WDIOS_ENABLECARD;//WDIOS_ENABLECARD 0x0002
         printf("return ENOTTY,if -1,success:%d\n",ioctl(fd,WDIOC_SETOPTIONS,&i));
         i=atoi(argv[1]);
         printf("put_user return,if 0,success:%d\n",ioctl(fd,WDIOC_SETTIMEOUT,&i));
         //读新的设置时间
    
         printf("put_usr return,if 0,success:%d\n",ioctl(fd,WDIOC_GETTIMEOUT,&i));
    
    
         while(1)
         {
        
               zsleep(100);
               if((c=Getch())!=27){
        
                    //输入如果不是ESC，就喂狗，否则不喂狗，到时间后系统重启
            printf("keep alive \n");
                    ioctl(fd,WDIOC_KEEPALIVE,NULL);
                    //write(fd,NULL,1);     //同样是喂狗
    
               }
         }
        close(fd);   //关闭设备
         return 0;
    }

执行:

gcc watchdog.c -o watchdog
    sudo ./watchdog 10

成功的话出现下面的提示：

open success
    options is 33152,identity is Synopsys DesignWare Watchdog
    put_usr return,if 0,success:0
    The old reset time is: 21
    return ENOTTY,if -1,success:-1
    return ENOTTY,if -1,success:-1
    put_user return,if 0,success:0
    put_usr return,if 0,success:0

一定要`open success`，`Synopsys DesignWare Watchdog`出现这个就是基于IP的watchdog，只要不是soft watchdog字样就行了。`The old reset time is: 21` 这个`21`就是默认的喂狗间隔，如果超过时间没有敲键盘（喂狗），设备就会自动重新启动，无视一切命令。

1.  线刷内核

本来有了上面的命令已经够用了，还有一种方法是rockchip官方提供的分区刷入，需要借助瑞芯微开发工具。你把boot.img和paramter.txt复制到windows桌面，打开瑞芯微刷机工具，按照我的选，指定两个文件的位置，其他的选项不要勾选，使设备进入boot loader模式然后点击执行，等待刷入完成。  
![在这里插入图片描述][cd84f7dd933d4999aec504effb79a7bd.png]  
刷入完成之后，系统会重启进入，这个时候就可以测试/dev/watchdog了。

1.  linux线刷

其实rockchip还提供了一种基于linux的线刷tool叫upgrade\_tool，这里我不说它了，因为我也很少用，而且比windows难用不少，我不推荐。供大家自行研究学习。

1.  多说一句

这里很关键的一个点就是你刷入的boot.img在linux上的大小一定不能超过分区最大容量，比如我前面贴出来的我的boot分区容量是64M，我编译出来的boot.img如果超过64M就不能使用分区刷入了，只能改为完整镜像刷入。还有我前面遗留的问题boot.img有33M而分区表里的容量只有20M，这怎么可能呢？实际上完整镜像是可以刷入的，33M的内核分区也变成了64M，说明检测到容量不够自动扩容了，这个应该是`刷机工具`完成的，扩容粒度应该是32M的倍数。这个留一个悬念，我还没有完全找到控制扩容的地方。

### 4.软硬结合 ###

之前说要把软件看门狗和硬件看门狗结合起来，完成一个晚上的看门狗功能，也省去了写代码的烦恼。

sudo apt install watchdog

watchdog知道的是支持Ubuntu、Centos、Debian的，其他的应该也支持，只是我没有用过。

我们要改两个文件

/etc/default/watchdog

# Start watchdog at boot time? 0 or 1
    run_watchdog=1
    # Start wd_keepalive after stopping watchdog? 0 or 1
    run_wd_keepalive=1
    # Load module before starting watchdog
    #build-in
    watchdog_module="none"
    #module
    #watchdog_module="wd_wdt"
    #watchdog_module="Synopsys"
    # Specify additional watchdog options here (see manpage).
    watchdog_options="-v -s -c /etc/watchdog.conf"

`这个地方做个说明：watchdog_module的选项跟着内核构建方式来的，如果刚才选的构建方式是build-in，这个地方用none就行了，填其他的服务启动不起来。如果刚才内核编译选择的是module，就需要手动加载下了。`

/etc/watchdog.conf

ping                    = 10.0.20.1
    #ping                   = 44.104.88.254
    interface               = eth0
    #file                   = /var/log/messages
    #change                 = 1407
    
    # Uncomment to enable test. Setting one of these values to '0' disables it.
    # These values will hopefully never reboot your machine during normal use
    # (if your machine is really hung, the loadavg will go much higher than 25)
    #max-load-1             = 24
    #max-load-5             = 18
    #max-load-15            = 12
    
    # Note that this is the number of pages!
    # To get the real size, check how large the pagesize is on your machine.
    #min-memory             = 1
    #allocatable-memory     = 1
    
    #repair-binary          = /usr/sbin/repair
    #repair-timeout         = 60
    #test-binary            =
    #test-timeout           = 60
    
    # The retry-timeout and repair limit are used to handle errors in a more robust
    # manner. Errors must persist for longer than retry-timeout to action a repair
    # or reboot, and if repair-maximum attempts are made without the test passing a
    # reboot is initiated anyway.
    #retry-timeout          = 30
    #repair-maximum         = 1
    
    watchdog-device = /dev/watchdog
    
    # Defaults compiled into the binary
    temperature-sensor      = /sys/class/thermal/thermal_zone0/temp
    max-temperature         = 90
    
    # Defaults compiled into the binary
    admin                   = root
    interval                = 10
    logtick                 = 60
    log-dir                 = /var/log/watchdog
    
    # This greatly decreases the chance that watchdog won't be scheduled before
    # your machine is really loaded
    realtime                = yes
    priority                = 1
    
    # Check if rsyslogd is still running by enabling the following line
    pidfile                 = /var/run/rsyslogd.pid
    pidfile                 = /var/run/sshd.pid
    pidfile                 = /var/run/inetd.pid
    
    watchdog-timeout        = 60

接着执行:

sudo systemctl start watchdog
    systemctl status watchdog

如果没报错就是成功了，可喜可贺，终于还是到了这一步。至于watchdog.conf里的配置含义，我的另一篇博客说的很明白了，大家可以参照下看看。每一项的测试方法我就不说了，我每一个都测过了，效果很好，有不懂的可以评论区问我。

--------------------

## 总结 ##

1、不同的设备肯定不太一样，如果你和我设备一样或相近，那肯定适用于你。  
2、整个流程完整测试下来，证明是可行的。  
3、有问题请留言，我看到了会回复你的。

[linux watchdog]: https://blog.csdn.net/jiexijihe945/article/details/128021600
[cd84f7dd933d4999aec504effb79a7bd.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/31/67a182a4e59f4aa0b3a6b336fc9beb31.png