Systemd
啟動期間串列 getty 服務停止
我正在開發一個執行基於 Yocto 的 Linux 發行版的嵌入式設備。
其他人似乎在不同的條件下遇到了這個確切的問題，但似乎沒有找到解決方案。
我採用了庫存的 OpenSTLinux 發行版並開始一層一層地刪除（例如 X11），並且在此過程中破壞了一些帶走串列登錄控制台的東西。
奇怪的是，寫入 sdcard 映像後第一次啟動設備時出現登錄提示。但是，在隨後的引導中，登錄提示不再存在。
引導消息（通過串列埠列印）表明：
- 控制台參數傳遞給核心
- 有問題的串列埠已正確初始化
- 串列 Getty 實例已啟動，但立即停止
Starting kernel ... [ 0.000000] Booting Linux on physical CPU 0x0 [ 0.000000] Linux version 5.10.61 (oe-user@oe-host) (arm-ostl-linux-gnueabi-gcc (GCC) 9.3.0, GNU ld (GNU Binutils) 2.34.0.20200220) #1 SMP PREEMPT Thu Aug 26 12:51:21 1 [ 0.000000] CPU: ARMv7 Processor [410fc075] revision 5 (ARMv7), cr=10c5387d [ 0.000000] CPU: div instructions available: patching division code [ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache [ 0.000000] OF: fdt: Machine model: STMicroelectronics STM32MP157F-DK2 Discovery Board [ 0.000000] Memory policy: Data cache writealloc [ 0.000000] Reserved memory: created DMA memory pool at 0x10000000, size 0 MiB [ 0.000000] OF: reserved mem: initialized node mcuram2@10000000, compatible id shared-dma-pool [ 0.000000] Reserved memory: created DMA memory pool at 0x10040000, size 0 MiB [ 0.000000] OF: reserved mem: initialized node vdev0vring0@10040000, compatible id shared-dma-pool [ 0.000000] Reserved memory: created DMA memory pool at 0x10041000, size 0 MiB [ 0.000000] OF: reserved mem: initialized node vdev0vring1@10041000, compatible id shared-dma-pool [ 0.000000] Reserved memory: created DMA memory pool at 0x10042000, size 0 MiB [ 0.000000] OF: reserved mem: initialized node vdev0buffer@10042000, compatible id shared-dma-pool [ 0.000000] Reserved memory: created DMA memory pool at 0x10048000, size 0 MiB [ 0.000000] OF: reserved mem: initialized node mcu_rsc_table@10048000, compatible id shared-dma-pool [ 0.000000] Reserved memory: created DMA memory pool at 0x30000000, size 0 MiB [ 0.000000] OF: reserved mem: initialized node mcuram@30000000, compatible id shared-dma-pool [ 0.000000] Reserved memory: created DMA memory pool at 0x38000000, size 0 MiB [ 0.000000] OF: reserved mem: initialized node retram@38000000, compatible id shared-dma-pool [ 0.000000] cma: Reserved 128 MiB at 0xc7800000 [ 0.000000] Zone ranges: [ 0.000000] Normal [mem 0x00000000c0000000-0x00000000dfffffff] [ 0.000000] HighMem empty [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x00000000c0000000-0x00000000d3ffffff] [ 0.000000] node 0: [mem 0x00000000d4000000-0x00000000d7ffffff] [ 0.000000] node 0: [mem 0x00000000d8000000-0x00000000dfcfffff] [ 0.000000] node 0: [mem 0x00000000dfd00000-0x00000000dffeffff] [ 0.000000] node 0: [mem 0x00000000dfff0000-0x00000000dfffffff] [ 0.000000] Initmem setup node 0 [mem 0x00000000c0000000-0x00000000dfffffff] [ 0.000000] psci: probing for conduit method from DT. [ 0.000000] psci: PSCIv1.1 detected in firmware. [ 0.000000] psci: Using standard PSCI v0.2 function IDs [ 0.000000] psci: MIGRATE_INFO_TYPE not supported. [ 0.000000] psci: SMC Calling Convention v1.2 [ 0.000000] percpu: Embedded 20 pages/cpu s51788 r8192 d21940 u81920 [ 0.000000] Built 1 zonelists, mobility grouping on. Total pages: 129920 [ 0.000000] Kernel command line: root=PARTUUID=e91c4e10-16e6-4c0e-bd0e-77becf4a3582 rootwait rw console=ttySTM0,115200 [ 0.000000] Dentry cache hash table entries: 65536 (order: 6, 262144 bytes, linear) [ 0.000000] Inode-cache hash table entries: 32768 (order: 5, 131072 bytes, linear) [ 0.000000] mem auto-init: stack:off, heap alloc:off, heap free:off [ 0.000000] Memory: 297404K/524288K available (11264K kernel code, 1207K rwdata, 3308K rodata, 1024K init, 239K bss, 95812K reserved, 131072K cma-reserved, 0K highmem) [ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=2, Nodes=1 [ 0.000000] rcu: Preemptible hierarchical RCU implementation. [ 0.000000] rcu: RCU event tracing is enabled. [ 0.000000] Trampoline variant of Tasks RCU enabled. [ 0.000000] Tracing variant of Tasks RCU enabled. [ 0.000000] rcu: RCU calculated value of scheduler-enlistment delay is 10 jiffies. [ 0.000000] NR_IRQS: 16, nr_irqs: 16, preallocated irqs: 16 [ 0.000000] random: get_random_bytes called from start_kernel+0x388/0x560 with crng_init=0 [ 0.000000] arch_timer: cp15 timer(s) running at 24.00MHz (virt). [ 0.000000] clocksource: arch_sys_counter: mask: 0xffffffffffffff max_cycles: 0x588fe9dc0, max_idle_ns: 440795202592 ns [ 0.000008] sched_clock: 56 bits at 24MHz, resolution 41ns, wraps every 4398046511097ns [ 0.000024] Switching to timer-based delay loop, resolution 41ns [ 0.001420] Console: colour dummy device 80x30 [ 0.001477] Calibrating delay loop (skipped), value calculated using timer frequency.. 48.00 BogoMIPS (lpj=240000) [ 0.001503] pid_max: default: 32768 minimum: 301 [ 0.001721] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) [ 0.001743] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) [ 0.002888] CPU: Testing write buffer coherency: ok [ 0.003300] /cpus/cpu@0 missing clock-frequency property [ 0.003342] /cpus/cpu@1 missing clock-frequency property [ 0.003359] CPU0: thread -1, cpu 0, socket 0, mpidr 80000000 [ 0.004407] Setting up static identity map for 0xc0100000 - 0xc0100060 [ 0.004588] rcu: Hierarchical SRCU implementation. [ 0.005816] smp: Bringing up secondary CPUs ... [ 0.006874] CPU1: thread -1, cpu 1, socket 0, mpidr 80000001 [ 0.007094] smp: Brought up 1 node, 2 CPUs [ 0.007120] SMP: Total of 2 processors activated (96.00 BogoMIPS). [ 0.007132] CPU: All CPU(s) started in SVC mode. [ 0.007882] devtmpfs: initialized [ 0.037995] VFP support v0.3: implementor 41 architecture 2 part 30 variant 7 rev 5 [ 0.038325] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns [ 0.038358] futex hash table entries: 512 (order: 3, 32768 bytes, linear) [ 0.044500] pinctrl core: initialized pinctrl subsystem [ 0.046193] NET: Registered protocol family 16 [ 0.049095] DMA: preallocated 256 KiB pool for atomic coherent allocations [ 0.050729] thermal_sys: Registered thermal governor 'step_wise' [ 0.051131] cpuidle: using governor menu [ 0.051484] hw-breakpoint: found 5 (+1 reserved) breakpoint and 4 watchpoint registers. [ 0.051503] hw-breakpoint: maximum watchpoint size is 8 bytes. [ 0.051847] Serial: AMBA PL011 UART driver [ 0.095434] stm32-pm-domain pm_domain: domain core-ret-power-domain registered [ 0.095479] stm32-pm-domain pm_domain: subdomain core-power-domain registered [ 0.095494] stm32-pm-domain pm_domain: domains probed [ 0.118494] SCSI subsystem initialized [ 0.119253] usbcore: registered new interface driver usbfs [ 0.119330] usbcore: registered new interface driver hub [ 0.119409] usbcore: registered new device driver usb [ 0.119669] pps_core: LinuxPPS API ver. 1 registered [ 0.119684] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti <giometti@linux.it> [ 0.119716] PTP clock support registered [ 0.120538] arm-scmi firmware:scmi0: SCMI Notifications - Core Enabled. [ 0.120621] arm-scmi firmware:scmi0: SCMI Protocol v2.0 'ST:' Firmware version 0x0 [ 0.123567] clocksource: Switched to clocksource arch_sys_counter [ 1.235280] simple-framebuffer dfd00000.framebuffer: framebuffer at 0xdfd00000, 0xbb800 bytes, mapped to 0x(ptrval) [ 1.235313] simple-framebuffer dfd00000.framebuffer: format=r5g6b5, mode=480x800x16, linelength=960 [ 1.235745] simple-framebuffer dfd00000.framebuffer: fb0: simplefb registered! [ 1.247748] NET: Registered protocol family 2 [ 1.248000] IP idents hash table entries: 8192 (order: 4, 65536 bytes, linear) [ 1.249208] tcp_listen_portaddr_hash hash table entries: 512 (order: 0, 6144 bytes, linear) [ 1.249362] TCP established hash table entries: 4096 (order: 2, 16384 bytes, linear) [ 1.249423] TCP bind hash table entries: 4096 (order: 3, 32768 bytes, linear) [ 1.249502] TCP: Hash tables configured (established 4096 bind 4096) [ 1.249666] UDP hash table entries: 256 (order: 1, 8192 bytes, linear) [ 1.249714] UDP-Lite hash table entries: 256 (order: 1, 8192 bytes, linear) [ 1.250289] NET: Registered protocol family 1 [ 1.251232] RPC: Registered named UNIX socket transport module. [ 1.251258] RPC: Registered udp transport module. [ 1.251269] RPC: Registered tcp transport module. [ 1.251280] RPC: Registered tcp NFSv4.1 backchannel transport module. [ 1.251624] Trying to unpack rootfs image as initramfs... [ 1.547733] Freeing initrd memory: 3548K [ 1.548702] hw perfevents: enabled with armv7_cortex_a7 PMU driver, 5 counters available [ 1.550424] Initialise system trusted keyrings [ 1.550811] workingset: timestamp_bits=14 max_order=17 bucket_order=3 [ 1.559823] squashfs: version 4.0 (2009/01/31) Phillip Lougher [ 1.561119] NFS: Registering the id_resolver key type [ 1.561177] Key type id_resolver registered [ 1.561189] Key type id_legacy registered [ 1.561340] nfs4filelayout_init: NFSv4 File Layout Driver Registering... [ 1.561356] nfs4flexfilelayout_init: NFSv4 Flexfile Layout Driver Registering... [ 1.561538] ntfs: driver 2.1.32 [Flags: R/O]. [ 1.561806] jffs2: version 2.2. (NAND) �© 2001-2006 Red Hat, Inc. [ 1.562580] fuse: init (API version 7.32) [ 1.563491] NET: Registered protocol family 38 [ 1.563518] Key type asymmetric registered [ 1.563531] Asymmetric key parser 'x509' registered [ 1.563687] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 246) [ 1.563705] io scheduler mq-deadline registered [ 1.563717] io scheduler kyber registered [ 1.575020] STM32 USART driver initialized [ 1.594625] brd: module loaded [ 1.599100] random: fast init done [ 1.603858] random: crng init done [ 1.606905] loop: module loaded [ 1.611950] libphy: Fixed MDIO Bus: probed [ 1.613824] CAN device driver interface [ 1.615651] pegasus: v0.9.3 (2013/04/25), Pegasus/Pegasus II USB Ethernet driver [ 1.615738] usbcore: registered new interface driver pegasus [ 1.615812] usbcore: registered new interface driver asix [ 1.615866] usbcore: registered new interface driver ax88179_178a [ 1.615917] usbcore: registered new interface driver cdc_ether [ 1.615984] usbcore: registered new interface driver smsc75xx [ 1.616061] usbcore: registered new interface driver smsc95xx [ 1.616114] usbcore: registered new interface driver net1080 [ 1.616166] usbcore: registered new interface driver cdc_subset [ 1.616216] usbcore: registered new interface driver zaurus [ 1.616292] usbcore: registered new interface driver cdc_ncm [ 1.617608] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver [ 1.617668] ehci-platform: EHCI generic platform driver [ 1.618061] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver [ 1.618100] ohci-platform: OHCI generic platform driver [ 1.618735] usbcore: registered new interface driver usb-storage [ 1.622124] i2c /dev entries driver [ 1.626527] stm32-cpufreq stm32-cpufreq: Failed to get chip info: -517 [ 1.627688] sdhci: Secure Digital Host Controller Interface driver [ 1.627708] sdhci: Copyright(c) Pierre Ossman [ 1.627718] Synopsys Designware Multimedia Card Interface Driver [ 1.628129] sdhci-pltfm: SDHCI platform and OF driver helper [ 1.629272] ledtrig-cpu: registered to indicate activity on CPUs [ 1.629504] SMCCC: SOC_ID: ID = jep106:0020:0500 Revision = 0x00002001 [ 1.629917] usbcore: registered new interface driver usbhid [ 1.629933] usbhid: USB HID core driver [ 1.631216] remoteproc remoteproc0: releasing m4 [ 1.633687] NET: Registered protocol family 17 [ 1.633733] can: controller area network core [ 1.633848] NET: Registered protocol family 29 [ 1.633862] can: raw protocol [ 1.633877] can: broadcast manager protocol [ 1.633897] can: netlink gateway - max_hops=1 [ 1.634634] Key type dns_resolver registered [ 1.634797] ThumbEE CPU extension supported. [ 1.634826] Registering SWP/SWPB emulation handler [ 1.635245] registered taskstats version 1 [ 1.635271] Loading compiled-in X.509 certificates [ 1.671331] stm32-mdma 58000000.dma-controller: STM32 MDMA driver registered [ 1.674576] stm32-dma 48000000.dma-controller: STM32 DMA driver registered [ 1.676863] stm32-dma 48001000.dma-controller: STM32 DMA driver registered [ 1.685886] stm_thermal 50028000.thermal: stm_thermal_probe: Driver initialized successfully [ 1.692265] remoteproc remoteproc0: releasing m4 [ 1.693045] /soc/interrupt-controller@5000d000: bank0 [ 1.693069] /soc/interrupt-controller@5000d000: bank1 [ 1.693085] /soc/interrupt-controller@5000d000: bank2 [ 1.697079] stm32mp157-pinctrl soc:pin-controller@50002000: GPIOA bank added [ 1.698997] stm32mp157-pinctrl soc:pin-controller@50002000: GPIOB bank added [ 1.700879] stm32mp157-pinctrl soc:pin-controller@50002000: GPIOC bank added [ 1.702782] stm32mp157-pinctrl soc:pin-controller@50002000: GPIOD bank added [ 1.704755] stm32mp157-pinctrl soc:pin-controller@50002000: GPIOE bank added [ 1.706924] stm32mp157-pinctrl soc:pin-controller@50002000: GPIOF bank added [ 1.708740] stm32mp157-pinctrl soc:pin-controller@50002000: GPIOG bank added [ 1.710511] stm32mp157-pinctrl soc:pin-controller@50002000: GPIOH bank added [ 1.712226] stm32mp157-pinctrl soc:pin-controller@50002000: GPIOI bank added [ 1.712535] stm32mp157-pinctrl soc:pin-controller@50002000: Pinctrl STM32 initialized [ 1.715425] stm32mp157-pinctrl soc:pin-controller-z@54004000: GPIOZ bank added [ 1.715464] stm32mp157-pinctrl soc:pin-controller-z@54004000: Pinctrl STM32 initialized [ 1.718602] 4000e000.serial: ttySTM3 at MMIO 0x4000e000 (irq = 61, base_baud = 4000000) is a stm32-usart [ 1.718929] serial serial0: tty port ttySTM3 registered [ 1.720797] stm32-usart 40010000.serial: interrupt mode for rx (no dma) [ 1.720823] stm32-usart 40010000.serial: interrupt mode for tx (no dma) [ 1.720858] 40010000.serial: ttySTM0 at MMIO 0x40010000 (irq = 62, base_baud = 4000000) is a stm32-usart [ 2.965639] printk: console [ttySTM0] enabled ... Welcome to ST OpenSTLinux - Weston - (A Yocto Project Based Distro) 3.1.11-snapshot-20211216 (dunfell)! [ 5.867882] systemd[1]: Set hostname to <stm32mp1>. [ 5.882917] systemd[1]: Hardware watchdog 'STM32 Independent Watchdog', version 0 [ 5.890326] systemd[1]: Set hardware watchdog to 32s. [ 6.505443] systemd[1]: Unnecessary job for /dev/ttySTM0 was removed. [ 6.517357] systemd[1]: Created slice system-getty.slice. [ OK ] Created slice system-getty.slice. [ 6.557278] systemd[1]: Created slice system-serial\x2dgetty.slice. [ OK ] Created slice system-serial\x2dgetty.slice. [ 6.597028] systemd[1]: Created slice User and Session Slice. [ OK ] Created slice User and Session Slice. [ 6.634855] systemd[1]: Started Dispatch Password Requests to Console Directory Watch. [ OK ] Started Dispatch Password �…ts to Console Directory Watch. [ 6.674597] systemd[1]: Started Forward Password Requests to Wall Directory Watch. [ OK ] Started Forward Password R�…uests to Wall Directory Watch. [ 6.714486] systemd[1]: Reached target Paths. [ OK ] Reached target Paths. [ 6.744085] systemd[1]: Reached target Remote File Systems. [ OK ] Reached target Remote File Systems. [ 6.784102] systemd[1]: Reached target Slices. [ OK ] Reached target Slices. [ 6.814158] systemd[1]: Reached target Swap. [ OK ] Reached target Swap. [ 6.884002] systemd[1]: Listening on RPCbind Server Activation Socket. [ OK ] Listening on RPCbind Server Activation Socket. [ 6.924179] systemd[1]: Reached target RPC Port Mapper. [ OK ] Reached target RPC Port Mapper. [ 6.965725] systemd[1]: Listening on Syslog Socket. [ OK ] Listening on Syslog Socket. [ 7.026252] systemd[1]: Listening on Process Core Dump Socket. [ OK ] Listening on Process Core Dump Socket. [ 7.064801] systemd[1]: Listening on initctl Compatibility Named Pipe. [ OK ] Listening on initctl Compatibility Named Pipe. [ 7.113194] systemd[1]: Condition check resulted in Journal Audit Socket being skipped. [ 7.121650] systemd[1]: Listening on Journal Socket (/dev/log). [ OK ] Listening on Journal Socket (/dev/log). [ 7.155508] systemd[1]: Listening on Journal Socket. [ OK ] Listening on Journal Socket. [ 7.195987] systemd[1]: Listening on Network Service Netlink Socket. [ OK ] Listening on Network Service Netlink Socket. [ 7.235479] systemd[1]: Listening on udev Control Socket. [ OK ] Listening on udev Control Socket. [ 7.274985] systemd[1]: Listening on udev Kernel Socket. [ OK ] Listening on udev Kernel Socket. [ 7.315694] systemd[1]: Condition check resulted in Huge Pages File System being skipped. [ 7.333008] systemd[1]: Mounting POSIX Message Queue File System... Mounting POSIX Message Queue File System... [ 7.384647] systemd[1]: Mounting Kernel Debug File System... Mounting Kernel Debug File System... [ 7.437495] systemd[1]: Mounting Temporary Directory (/tmp)... Mounting Temporary Directory (/tmp)... [ 7.485149] systemd[1]: Starting Create list of static device nodes for the current kernel... Starting Create list of st�…odes for the current kernel... [ 7.545605] systemd[1]: Starting RPC Bind... Starting RPC Bind... [ 7.574602] systemd[1]: Condition check resulted in File System Check on Root Device being skipped. [ 7.592953] systemd[1]: Starting Journal Service... Starting Journal Service... [ 7.627247] systemd[1]: Condition check resulted in Load Kernel Modules being skipped. [ 7.640351] systemd[1]: Mounting FUSE Control File System... Mounting FUSE Control File System... [ 7.660372] systemd[1]: Mounting Kernel Configuration File System... Mounting Kernel Configuration File System... [ 7.684598] systemd[1]: Starting Remount Root and Kernel File Systems... Starting Remount Root and Kernel File Systems... [ 7.732844] EXT4-fs (mmcblk0p6): re-mounted. Opts: (null) [ 7.744149] systemd[1]: Starting Apply Kernel Variables... Starting Apply Kernel Variables... [ 7.775175] systemd[1]: Starting udev Coldplug all Devices... Starting udev Coldplug all Devices... [ 7.846450] systemd[1]: Started RPC Bind. [ OK ] Started RPC Bind. [ 7.884892] systemd[1]: Started Journal Service. [ OK ] Started Journal Service. [ OK ] Mounted POSIX Message Queue File System. [ OK ] Mounted Kernel Debug File System. [ OK ] Mounted Temporary Directory (/tmp). [ OK ] Started Create list of sta�… nodes for the current kernel. [ OK ] Mounted FUSE Control File System. [ OK ] Mounted Kernel Configuration File System. [ OK ] Started Remount Root and Kernel File Systems. [ OK ] Started Apply Kernel Variables. Starting Flush Journal to Persistent Storage... [ 8.261556] systemd-journald[257]: Received client request to flush runtime journal. Starting Create Static Device Nodes in /dev... [ OK ] Started Flush Journal to Persistent Storage. [ OK ] Started Create Static Device Nodes in /dev. [ OK ] Reached target Local File Systems (Pre). Mounting /var/volatile... Starting udev Kernel Device Manager... [ OK ] Mounted /var/volatile. Starting Load/Save Random Seed... [ OK ] Reached target Local File Systems. Starting Create Volatile Files and Directories... [ OK ] Started Load/Save Random Seed. [ OK ] Started udev Kernel Device Manager. [ OK ] Started udev Coldplug all Devices. [ OK ] Started Create Volatile Files and Directories. Starting Network Time Synchronization... Starting Update UTMP about System Boot/Shutdown... [ OK ] Started Update UTMP about System Boot/Shutdown. [ OK ] Started Network Time Synchronization. [ OK ] Reached target System Initialization. [ OK ] Started Daily Cleanup of Temporary Directories. [ OK ] Reached target System Time Set. [ OK ] Reached target System Time Synchronized. [ OK ] Reached target Timers. [ OK ] Listening on Avahi mDNS/DNS-SD Stack Activation Socket. [ OK ] Listening on D-Bus System Message Bus Socket. [ OK ] Listening on dropbear.socket. [ OK ] Reached target Sockets. [ OK ] Reached target Basic System. [ OK ] Started Kernel Logging Service. [ OK ] Started System Logging Service. [ 9.739841] Bluetooth: Core ver 2.22 [ 9.742261] NET: Registered protocol family 31 [ 9.771239] st,stm32-i2s 4000b000.audio-controller: No cache defaults, reading back from HW [ OK ] Started D-Bus System Message Bus. [ 9.808251] stm32-cryp 54001000.cryp: will run requests pump with realtime priority [ 9.816453] Bluetooth: HCI device and connection manager initialized [ 9.821463] Bluetooth: HCI socket layer initialized [ 9.834299] stm32-hash 54002000.hash: will run requests pump with realtime priority [ OK ] Started Gett[ 9.899739] stm32-cryp 54001000.cryp: Initialized y on tty1. [ 9.914298] Bluetooth: L2CAP socket layer initialized [ 9.918052] Bluetooth: SCO socket layer initialized Starting IPv6 Packet Filtering Framework... Starting IPv4 Packet Filtering Framework... [ OK ] Started Serial Getty on ttySTM0. [ 10.030315] Bluetooth: HCI UART driver ver 2.3 [ 10.043752] stm32-hash 54002000.hash: Init HASH done HW ver 23 DMA mode 1 [ 10.051633] stm32-crc32 58009000.crc: Initialized Stopping Serial Getty on ttySTM0... Starting Login Service... [ 10.129884] Bluetooth: HCI UART protocol H4 registered [ 10.144424] galcore: loading out-of-tree module taints kernel. [ OK ] Started TEE Supplicant. [ 10.171541] Bluetooth: HCI UART protocol Broadcom registered [ OK ] Started IPv6 Packet Filtering Framework. [ OK ] Started IPv4 Packet Filtering Framework. [ 10.351280] Galcore version 6.4.3.279124 [ 10.363263] cfg80211: Loading compiled-in X.509 certificates for regulatory database [ OK ] Stopped Serial Getty on ttySTM0. [ 10.480989] cfg80211: Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7' [ 10.551612] platform regulatory.0: Direct firmware load for regulatory.db failed with error -2 [ 10.564325] cfg80211: failed to load regulatory.db [ 10.567851] Bluetooth: hci0: BCM: chip id 94 [ 10.572661] Bluetooth: hci0: BCM: features 0x2e [ 10.579068] Bluetooth: hci0: BCM43430A1 [ 10.581554] Bluetooth: hci0: BCM43430A1 (001.002.009) build 0000 [ 10.593980] Bluetooth: hci0: BCM43430A1 'brcm/BCM43430A1.hcd' Patch [ 10.719466] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43430-sdio for chip BCM43430/1 [ 10.944323] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43430-sdio for chip BCM43430/1 [ 11.034191] brcmfmac: brcmf_c_preinit_dcmds: Firmware: BCM43430/1 wl0: Feb 16 2020 22:39:24 version 7.45.98.97 (r724416 CY) FWID 01-bf41ed64 [ 11.246819] Bluetooth: hci0: BCM4343WA1 37.4MHz Murata Type-1DX BT4.2-0093 [ 11.252320] Bluetooth: hci0: BCM43430A1 (001.002.009) build 0395 [ 11.337201] cs42l51 0-004a: Cirrus Logic CS42L51, Revision: 01 [ OK ] Started Login Service. [ OK ] Created slice system-systemd\x2dbacklight.slice. [ OK ] Reached target Bluetooth. [ OK ] Reached target Login Prompts. [ OK ] Reached target Network (Pre). [ OK ] Reached target Sound Card. [ OK ] Reached target Hardware activated USB gadget. Starting Load/Save Screen �…of backlight:5a000000.dsi.0... Starting Network Service... [FAILED] Failed to start Load/Save �…s of backlight:5a000000.dsi.0. See 'systemctl status systemd-backlight�…ht:5a000000.dsi.0.service' for details. [ OK ] Started Network Service. Starting Network Name Resolutio[ 12.423795] stm32-dwmac 5800a000.ethernet eth0: PHY [stmmac-0:00] driver [RTL8211F Gigabit Ethernet] (irq=POLL) n... [ 12.438978] dwmac4: Master AXI performs any burst length [ 12.442981] stm32-dwmac 5800a000.ethernet eth0: No Safety Features support found [ 12.451037] stm32-dwmac 5800a000.ethernet eth0: IEEE 1588-2008 Advanced Timestamp supported [ 12.460125] stm32-dwmac 5800a000.ethernet eth0: registered PTP clock [ 12.468558] stm32-dwmac 5800a000.ethernet eth0: configuring for phy/rgmii-id link mode [ OK ] Started Network Name Resolution. [ OK ] Reached target Network. [ OK ] Reached target Host and Network Name Lookups. Starting Avahi mDNS/DNS-SD Stack... [ OK ] Started Avahi mDNS/DNS-SD Stack. [ OK ] Reached target Multi-User System. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. [ 16.716957] stm32-dwmac 5800a000.ethernet eth0: Link is Up - 1Gbps/Full - flow control rx/tx [ 16.724237] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready [ 33.753839] usb33: supplied by vdd_usb [ 33.756433] vref: supplied by vdd [ 33.759707] vref: disabling [ 33.762296] vdda: disablingGetty 服務的狀態表明它由於串口設備不活動而停止：
$ systemctl status serial-getty@ttySTM0.service ● serial-getty@ttySTM0.service - Serial Getty on ttySTM0 Loaded: loaded (/lib/systemd/system/serial-getty@.service; enabled; vendor preset: disabled) Active: inactive (dead) since Wed 2021-12-22 20:15:56 UTC; 3min 35s ago Docs: man:agetty(8) man:systemd-getty-generator(8) http://0pointer.de/blog/projects/serial-console.html Process: 321 ExecStart=/sbin/agetty -8 --autologin root -L ttySTM0 115200 $TERM (code=killed, signal=HUP) Main PID: 321 (code=killed, signal=HUP) Dec 22 20:15:56 stm32mp1 systemd[1]: Started Serial Getty on ttySTM0. Dec 22 20:15:56 stm32mp1 systemd[1]: serial-getty@ttySTM0.service: Unit is bound to inactive unit dev-ttySTM0.device. Stopping, too. Dec 22 20:15:56 stm32mp1 systemd[1]: Stopping Serial Getty on ttySTM0... Dec 22 20:15:56 stm32mp1 systemd[1]: serial-getty@ttySTM0.service: Succeeded. Dec 22 20:15:56 stm32mp1 systemd[1]: Stopped Serial Getty on ttySTM0.但是，設備列表表明它可用且處於活動狀態：
$ systemctl --all --full -t device UNIT LOAD ACTIVE SUB DESCRIPTION ... dev-ttySTM0.device loaded active plugged /dev/ttySTM0 ...誰能提出問題可能是什麼？
或者你能建議我還能做些什麼來找到問題的根源嗎？
謝謝你。
我最終弄清楚了問題所在。
供應商提供了一個方法來覆蓋
/lib/systemd/system/serial-getty@.service文件的內容。因此，雖然上游來源包含以下行：
After=dev-%i.device systemd-user-sessions.service plymouth-quit-wait.service getty-pre.target最終在 rootfs 上的服務文件將該行修改為：
After=systemd-user-sessions.service plymouth-quit-wait.service getty-pre.target最終結果是一種競爭條件，有時會由於設備不可用而導致串列 getty 服務失敗。
我不得不侵入 systemd 源以添加一些調試消息以查看確切的事件序列。