# Kernel Ring Buffer

```bash
DMESG(1)                         User Commands                        DMESG(1)

NAME
       dmesg - print or control the kernel ring buffer

SYNOPSIS
       dmesg [options]

       dmesg --clear
       dmesg --read-clear [options]
       dmesg --console-level level
       dmesg --console-on
       dmesg --console-off

DESCRIPTION
       dmesg is used to examine or control the kernel ring buffer.

       The default action is to display all messages from the kernel ring buf‐
       fer.
...
```

```bash
pi@raspberrypi:~ $ dmesg
[    0.000000] Booting Linux on physical CPU 0x0
[    0.000000] Linux version 4.9.59-v7+ (dc4@dc4-XPS13-9333) (gcc version 4.9.3 (crosstool-NG crosstool-ng-1.22.0-88-g8460611) ) #1047 SMP Sun Oct 29 12:19:23 GMT 2017
[    0.000000] CPU: ARMv7 Processor [410fd034] revision 4 (ARMv7), cr=10c5383d
[    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: Raspberry Pi 3 Model B Rev 1.2
[    0.000000] cma: Reserved 8 MiB at 0x3ac00000
[    0.000000] Memory policy: Data cache writealloc
[    0.000000] On node 0 totalpages: 242688
[    0.000000] free_area_init_node: node 0, pgdat 80c6f380, node_mem_map ba3a1000
[    0.000000]   Normal zone: 2133 pages used for memmap
[    0.000000]   Normal zone: 0 pages reserved
[    0.000000]   Normal zone: 242688 pages, LIFO batch:31
[    0.000000] percpu: Embedded 14 pages/cpu @ba35b000 s25600 r8192 d23552 u57344
[    0.000000] pcpu-alloc: s25600 r8192 d23552 u57344 alloc=14*4096
[    0.000000] pcpu-alloc: [0] 0 [0] 1 [0] 2 [0] 3 
[    0.000000] Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 240555
[    0.000000] Kernel command line: 8250.nr_uarts=0 bcm2708_fb.fbwidth=1360 bcm2708_fb.fbheight=768 bcm2708_fb.fbswap=1 vc_mem.mem_base=0x3ec00000 vc_mem.mem_size=0x40000000  dwc_otg.lpm_enable=0 console=ttyS0,115200 console=tty1 root=PARTUUID=00aa1cb9-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait quiet splash plymouth.ignore-serial-consoles
[    0.000000] PID hash table entries: 4096 (order: 2, 16384 bytes)
[    0.000000] Dentry cache hash table entries: 131072 (order: 7, 524288 bytes)
[    0.000000] Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
[    0.000000] Memory: 940364K/970752K available (7168K kernel code, 486K rwdata, 2012K rodata, 1024K init, 770K bss, 22196K reserved, 8192K cma-reserved)
[    0.000000] Virtual kernel memory layout:
                   vector  : 0xffff0000 - 0xffff1000   (   4 kB)
                   fixmap  : 0xffc00000 - 0xfff00000   (3072 kB)
                   vmalloc : 0xbb800000 - 0xff800000   (1088 MB)
                   lowmem  : 0x80000000 - 0xbb400000   ( 948 MB)
                   modules : 0x7f000000 - 0x80000000   (  16 MB)
                     .text : 0x80008000 - 0x80800000   (8160 kB)
                     .init : 0x80b00000 - 0x80c00000   (1024 kB)
                     .data : 0x80c00000 - 0x80c79834   ( 487 kB)
                      .bss : 0x80c7b000 - 0x80d3b964   ( 771 kB)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1
[    0.000000] Hierarchical RCU implementation.
[    0.000000]     Build-time adjustment of leaf fanout to 32.
[    0.000000] NR_IRQS:16 nr_irqs:16 16
[    0.000000] arm_arch_timer: Architected cp15 timer(s) running at 19.20MHz (phys).
[    0.000000] clocksource: arch_sys_counter: mask: 0xffffffffffffff max_cycles: 0x46d987e47, max_idle_ns: 440795202767 ns
[    0.000007] sched_clock: 56 bits at 19MHz, resolution 52ns, wraps every 4398046511078ns
[    0.000019] Switching to timer-based delay loop, resolution 52ns
[    0.000295] Console: colour dummy device 80x30
[    0.000310] console [tty1] enabled
[    0.000330] Calibrating delay loop (skipped), value calculated using timer frequency.. 38.40 BogoMIPS (lpj=192000)
[    0.000345] pid_max: default: 32768 minimum: 301
[    0.000651] Mount-cache hash table entries: 2048 (order: 1, 8192 bytes)
[    0.000660] Mountpoint-cache hash table entries: 2048 (order: 1, 8192 bytes)
[    0.001666] Disabling memory control group subsystem
[    0.001738] CPU: Testing write buffer coherency: ok
[    0.001772] ftrace: allocating 22392 entries in 66 pages
[    0.048823] CPU0: update cpu_capacity 1024
[    0.048838] CPU0: thread -1, cpu 0, socket 0, mpidr 80000000
[    0.048874] Setting up static identity map for 0x100000 - 0x100034
[    0.050733] CPU1: update cpu_capacity 1024
[    0.050740] CPU1: thread -1, cpu 1, socket 0, mpidr 80000001
[    0.051425] CPU2: update cpu_capacity 1024
[    0.051432] CPU2: thread -1, cpu 2, socket 0, mpidr 80000002
[    0.052101] CPU3: update cpu_capacity 1024
[    0.052108] CPU3: thread -1, cpu 3, socket 0, mpidr 80000003
[    0.052195] Brought up 4 CPUs
[    0.052205] SMP: Total of 4 processors activated (153.60 BogoMIPS).
[    0.052209] CPU: All CPU(s) started in HYP mode.
[    0.052213] CPU: Virtualization extensions available.
[    0.053007] devtmpfs: initialized
[    0.064440] VFP support v0.3: implementor 41 architecture 3 part 40 variant 3 rev 4
[    0.064710] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[    0.064726] futex hash table entries: 1024 (order: 4, 65536 bytes)
[    0.065262] pinctrl core: initialized pinctrl subsystem
[    0.066168] NET: Registered protocol family 16
[    0.068513] DMA: preallocated 1024 KiB pool for atomic coherent allocations
[    0.077460] hw-breakpoint: found 5 (+1 reserved) breakpoint and 4 watchpoint registers.
[    0.077466] hw-breakpoint: maximum watchpoint size is 8 bytes.
[    0.077605] Serial: AMBA PL011 UART driver
[    0.079507] bcm2835-mbox 3f00b880.mailbox: mailbox enabled
[    0.080031] uart-pl011 3f201000.serial: could not find pctldev for node /soc/gpio@7e200000/uart0_pins, deferring probe
[    0.149657] bcm2835-dma 3f007000.dma: DMA legacy API manager at bb80f000, dmachans=0x1
[    0.151473] SCSI subsystem initialized
[    0.151623] usbcore: registered new interface driver usbfs
[    0.151699] usbcore: registered new interface driver hub
[    0.151789] usbcore: registered new device driver usb
[    0.158627] raspberrypi-firmware soc:firmware: Attached to firmware from 2017-10-24 17:09
[    0.160101] clocksource: Switched to clocksource arch_sys_counter
[    0.207117] VFS: Disk quotas dquot_6.6.0
[    0.207193] VFS: Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
[    0.207395] FS-Cache: Loaded
[    0.207643] CacheFiles: Loaded
[    0.219765] NET: Registered protocol family 2
[    0.220663] TCP established hash table entries: 8192 (order: 3, 32768 bytes)
[    0.220770] TCP bind hash table entries: 8192 (order: 4, 65536 bytes)
[    0.220955] TCP: Hash tables configured (established 8192 bind 8192)
[    0.221042] UDP hash table entries: 512 (order: 2, 16384 bytes)
[    0.221084] UDP-Lite hash table entries: 512 (order: 2, 16384 bytes)
[    0.221288] NET: Registered protocol family 1
[    0.221694] RPC: Registered named UNIX socket transport module.
[    0.221699] RPC: Registered udp transport module.
[    0.221704] RPC: Registered tcp transport module.
[    0.221708] RPC: Registered tcp NFSv4.1 backchannel transport module.
[    0.222760] hw perfevents: enabled with armv7_cortex_a7 PMU driver, 7 counters available
[    0.225051] workingset: timestamp_bits=14 max_order=18 bucket_order=4
[    0.241107] FS-Cache: Netfs 'nfs' registered for caching
[    0.242080] NFS: Registering the id_resolver key type
[    0.242106] Key type id_resolver registered
[    0.242111] Key type id_legacy registered
[    0.244498] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 251)
[    0.244600] io scheduler noop registered
[    0.244606] io scheduler deadline registered (default)
[    0.244876] io scheduler cfq registered
[    0.250509] BCM2708FB: allocated DMA memory fad10000
[    0.250532] BCM2708FB: allocated DMA channel 0 @ bb80f000
[    0.280246] Console: switching to colour frame buffer device 170x48
[    0.298482] bcm2835-rng 3f104000.rng: hwrng registered
[    0.298598] vc-mem: phys_addr:0x00000000 mem_base=0x3ec00000 mem_size:0x40000000(1024 MiB)
[    0.299124] vc-sm: Videocore shared memory driver
[    0.314280] brd: module loaded
[    0.323216] loop: module loaded
[    0.323227] Loading iSCSI transport class v2.0-870.
[    0.323765] usbcore: registered new interface driver smsc95xx
[    0.323780] dwc_otg: version 3.00a 10-AUG-2012 (platform bus)
[    0.551842] Core Release: 2.80a
[    0.551850] Setting default values for core params
[    0.551882] Finished setting default values for core params
[    0.752269] Using Buffer DMA mode
[    0.752275] Periodic Transfer Interrupt Enhancement - disabled
[    0.752279] Multiprocessor Interrupt Enhancement - disabled
[    0.752285] OTG VER PARAM: 0, OTG VER FLAG: 0
[    0.752299] Dedicated Tx FIFOs mode
[    0.752662] WARN::dwc_otg_hcd_init:1032: FIQ DMA bounce buffers: virt = 0xbad04000 dma = 0xfad04000 len=9024
[    0.752687] FIQ FSM acceleration enabled for :
               Non-periodic Split Transactions
               Periodic Split Transactions
               High-Speed Isochronous Endpoints
               Interrupt/Control Split Transaction hack enabled
[    0.752694] dwc_otg: Microframe scheduler enabled
[    0.752740] WARN::hcd_init_fiq:459: FIQ on core 1 at 0x8058f5b0
[    0.752750] WARN::hcd_init_fiq:460: FIQ ASM at 0x8058f920 length 36
[    0.752761] WARN::hcd_init_fiq:486: MPHI regs_base at 0xbb87a000
[    0.752822] dwc_otg 3f980000.usb: DWC OTG Controller
[    0.752855] dwc_otg 3f980000.usb: new USB bus registered, assigned bus number 1
[    0.752885] dwc_otg 3f980000.usb: irq 62, io mem 0x00000000
[    0.752933] Init: Port Power? op_state=1
[    0.752938] Init: Power Port (0)
[    0.753150] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
[    0.753160] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[    0.753169] usb usb1: Product: DWC OTG Controller
[    0.753176] usb usb1: Manufacturer: Linux 4.9.59-v7+ dwc_otg_hcd
[    0.753184] usb usb1: SerialNumber: 3f980000.usb
[    0.754005] hub 1-0:1.0: USB hub found
[    0.754042] hub 1-0:1.0: 1 port detected
[    0.754735] dwc_otg: FIQ enabled
[    0.754739] dwc_otg: NAK holdoff enabled
[    0.754743] dwc_otg: FIQ split-transaction FSM enabled
[    0.754756] Module dwc_common_port init
[    0.754980] usbcore: registered new interface driver usb-storage
[    0.755225] mousedev: PS/2 mouse device common for all mice
[    0.756204] bcm2835-wdt 3f100000.watchdog: Broadcom BCM2835 watchdog timer
[    0.756477] bcm2835-cpufreq: min=600000 max=1200000
[    0.756863] sdhci: Secure Digital Host Controller Interface driver
[    0.756867] sdhci: Copyright(c) Pierre Ossman
[    0.757145] sdhost-bcm2835 3f202000.sdhost: could not get clk, deferring probe
[    0.759318] mmc-bcm2835 3f300000.mmc: could not get clk, deferring probe
[    0.759417] sdhci-pltfm: SDHCI platform and OF driver helper
[    0.762041] ledtrig-cpu: registered to indicate activity on CPUs
[    0.762230] hidraw: raw HID events driver (C) Jiri Kosina
[    0.762418] usbcore: registered new interface driver usbhid
[    0.762422] usbhid: USB HID core driver
[    0.763214] vchiq: vchiq_init_state: slot_zero = 0xbad80000, is_master = 0
[    0.773847] [vc_sm_connected_init]: end - returning 0
[    0.774205] Initializing XFRM netlink socket
[    0.774227] NET: Registered protocol family 17
[    0.774346] Key type dns_resolver registered
[    0.774848] Registering SWP/SWPB emulation handler
[    0.775530] registered taskstats version 1
[    0.781796] uart-pl011 3f201000.serial: cts_event_workaround enabled
[    0.781866] 3f201000.serial: ttyAMA0 at MMIO 0x3f201000 (irq = 87, base_baud = 0) is a PL011 rev2
[    0.783439] sdhost: log_buf @ bad07000 (fad07000)
[    0.860135] mmc0: sdhost-bcm2835 loaded - DMA enabled (>1)
[    0.862350] mmc-bcm2835 3f300000.mmc: mmc_debug:0 mmc_debug2:0
[    0.862358] mmc-bcm2835 3f300000.mmc: DMA channel allocated
[    0.920237] of_cfs_init
[    0.920457] of_cfs_init: OK
[    0.920954] Waiting for root device PARTUUID=00aa1cb9-02...
[    0.930893] mmc0: host does not support reading read-only switch, assuming write-enable
[    0.932905] mmc0: new high speed SDHC card at address 1234
[    0.933570] mmcblk0: mmc0:1234 SA08G 7.25 GiB
[    0.935138]  mmcblk0: p1 p2
[    0.941242] mmc1: queuing unknown CIS tuple 0x80 (2 bytes)
[    0.942790] mmc1: queuing unknown CIS tuple 0x80 (3 bytes)
[    0.944337] mmc1: queuing unknown CIS tuple 0x80 (3 bytes)
[    0.947116] mmc1: queuing unknown CIS tuple 0x80 (7 bytes)
[    0.970206] Indeed it is in host mode hprt0 = 00021501
[    1.037745] random: fast init done
[    1.054005] EXT4-fs (mmcblk0p2): mounted filesystem with ordered data mode. Opts: (null)
[    1.054052] VFS: Mounted root (ext4 filesystem) readonly on device 179:2.
[    1.055188] devtmpfs: mounted
[    1.057039] Freeing unused kernel memory: 1024K
[    1.098350] mmc1: new high speed SDIO card at address 0001
[    1.170155] usb 1-1: new high-speed USB device number 2 using dwc_otg
[    1.170296] Indeed it is in host mode hprt0 = 00001101
[    1.400477] usb 1-1: New USB device found, idVendor=0424, idProduct=9514
[    1.400492] usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[    1.401330] hub 1-1:1.0: USB hub found
[    1.401425] hub 1-1:1.0: 5 ports detected
[    1.513692] systemd[1]: System time before build time, advancing clock.
[    1.642640] NET: Registered protocol family 10
[    1.663074] ip_tables: (C) 2000-2006 Netfilter Core Team
[    1.687567] systemd[1]: systemd 232 running in system mode. (+PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD +IDN)
[    1.688138] systemd[1]: Detected architecture arm.
[    1.689287] systemd[1]: Set hostname to <raspberrypi>.
[    1.720166] usb 1-1.1: new high-speed USB device number 3 using dwc_otg
[    1.850490] usb 1-1.1: New USB device found, idVendor=0424, idProduct=ec00
[    1.850505] usb 1-1.1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[    1.853314] smsc95xx v1.0.5
[    1.944109] smsc95xx 1-1.1:1.0 eth0: register 'smsc95xx' at usb-3f980000.usb-1.1, smsc95xx USB 2.0 Ethernet, b8:27:eb:68:da:f4
[    2.040152] usb 1-1.3: new high-speed USB device number 4 using dwc_otg
[    2.168270] systemd[1]: Listening on Journal Socket (/dev/log).
[    2.169368] systemd[1]: Set up automount Arbitrary Executable File Formats File System Automount Point.
[    2.169674] systemd[1]: Listening on Journal Socket.
[    2.171571] usb 1-1.3: New USB device found, idVendor=05e3, idProduct=0608
[    2.171585] usb 1-1.3: New USB device strings: Mfr=0, Product=1, SerialNumber=0
[    2.171594] usb 1-1.3: Product: USB2.0 Hub
[    2.172514] hub 1-1.3:1.0: USB hub found
[    2.172812] hub 1-1.3:1.0: 4 ports detected
[    2.189392] systemd[1]: Listening on fsck to fsckd communication Socket.
[    2.189656] systemd[1]: Listening on udev Kernel Socket.
[    2.189910] systemd[1]: Listening on udev Control Socket.
[    2.190758] systemd[1]: Created slice User and Session Slice.
[    2.313707] i2c /dev entries driver
[    2.490176] usb 1-1.3.3: new low-speed USB device number 5 using dwc_otg
[    2.626572] usb 1-1.3.3: New USB device found, idVendor=046d, idProduct=c05a
[    2.626589] usb 1-1.3.3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[    2.626598] usb 1-1.3.3: Product: USB Optical Mouse
[    2.626605] usb 1-1.3.3: Manufacturer: Logitech
[    2.635785] input: Logitech USB Optical Mouse as /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.3/1-1.3.3/1-1.3.3:1.0/0003:046D:C05A.0001/input/input0
[    2.636388] hid-generic 0003:046D:C05A.0001: input,hidraw0: USB HID v1.11 Mouse [Logitech USB Optical Mouse] on usb-3f980000.usb-1.3.3/input0
[    2.730149] usb 1-1.3.4: new low-speed USB device number 6 using dwc_otg
[    2.762728] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null)
[    2.867026] systemd-journald[118]: Received request to flush runtime journal from PID 1
[    2.871226] usb 1-1.3.4: New USB device found, idVendor=046d, idProduct=c31c
[    2.871244] usb 1-1.3.4: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[    2.871260] usb 1-1.3.4: Product: USB Keyboard
[    2.871267] usb 1-1.3.4: Manufacturer: Logitech
[    2.886091] input: Logitech USB Keyboard as /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.3/1-1.3.4/1-1.3.4:1.0/0003:046D:C31C.0002/input/input1
[    2.952917] hid-generic 0003:046D:C31C.0002: input,hidraw1: USB HID v1.10 Keyboard [Logitech USB Keyboard] on usb-3f980000.usb-1.3.4/input0
[    2.969956] input: Logitech USB Keyboard as /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.3/1-1.3.4/1-1.3.4:1.1/0003:046D:C31C.0003/input/input2
[    3.030620] hid-generic 0003:046D:C31C.0003: input,hidraw2: USB HID v1.10 Device [Logitech USB Keyboard] on usb-3f980000.usb-1.3.4/input1
[    3.524055] gpiomem-bcm2835 3f200000.gpiomem: Initialised: Registers at 0x3f200000
[    3.830958] brcmfmac: F1 signature read @0x18000000=0x1541a9a6
[    3.838058] usbcore: registered new interface driver brcmfmac
[    4.045867] brcmfmac: Firmware version = wl0: Aug  7 2017 00:46:29 version 7.45.41.46 (r666254 CY) FWID 01-f8a78378
[    4.046831] brcmfmac: brcmf_c_preinit_dcmds: CLM version = API: 12.2 Data: 7.11.15 Compiler: 1.24.2 ClmImport: 1.24.1 Creation: 2014-05-26 10:53:55 Inc Data: 9.10.41 Inc Compiler: 1.29.4 Inc ClmImport: 1.36.3 Creation: 2017-08-07 00:37:47 
[    4.942461] uart-pl011 3f201000.serial: no DMA platform data
[    5.455926] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[    5.456093] brcmfmac: power management disabled
[    5.852483] smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup
[    5.852721] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[    6.476707] Adding 102396k swap on /var/swap.  Priority:-1 extents:1 across:102396k SSFS
[    7.375104] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[    7.375800] smsc95xx 1-1.1:1.0 eth0: link up, 100Mbps, full-duplex, lpa 0xC5E1
[    9.438277] Bluetooth: Core ver 2.22
[    9.438365] NET: Registered protocol family 31
[    9.438368] Bluetooth: HCI device and connection manager initialized
[    9.439211] Bluetooth: HCI socket layer initialized
[    9.439221] Bluetooth: L2CAP socket layer initialized
[    9.439247] Bluetooth: SCO socket layer initialized
[    9.461150] Bluetooth: HCI UART driver ver 2.3
[    9.461157] Bluetooth: HCI UART protocol H4 registered
[    9.461160] Bluetooth: HCI UART protocol Three-wire (H5) registered
[    9.461253] Bluetooth: HCI UART protocol Broadcom registered
[    9.689939] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[    9.689948] Bluetooth: BNEP filters: protocol multicast
[    9.689963] Bluetooth: BNEP socket layer initialized
[    9.748062] Bluetooth: RFCOMM TTY layer initialized
[    9.748090] Bluetooth: RFCOMM socket layer initialized
[    9.748110] Bluetooth: RFCOMM ver 1.11
[   12.936040] fuse init (API version 7.26)
[   19.839955] random: crng init done
[   38.486026] usb 1-1.3: USB disconnect, device number 4
[   38.486042] usb 1-1.3.3: USB disconnect, device number 5
[   38.561228] usb 1-1.3.4: USB disconnect, device number 6
[   68.220200] usb 1-1.3: new high-speed USB device number 7 using dwc_otg
[   68.351618] usb 1-1.3: New USB device found, idVendor=05e3, idProduct=0608
[   68.351634] usb 1-1.3: New USB device strings: Mfr=0, Product=1, SerialNumber=0
[   68.351643] usb 1-1.3: Product: USB2.0 Hub
[   68.354864] hub 1-1.3:1.0: USB hub found
[   68.355903] hub 1-1.3:1.0: 4 ports detected
[   68.670157] usb 1-1.3.3: new low-speed USB device number 8 using dwc_otg
[   68.806549] usb 1-1.3.3: New USB device found, idVendor=046d, idProduct=c05a
[   68.806562] usb 1-1.3.3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[   68.806571] usb 1-1.3.3: Product: USB Optical Mouse
[   68.806578] usb 1-1.3.3: Manufacturer: Logitech
[   68.814213] input: Logitech USB Optical Mouse as /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.3/1-1.3.3/1-1.3.3:1.0/0003:046D:C05A.0004/input/input3
[   68.817549] hid-generic 0003:046D:C05A.0004: input,hidraw0: USB HID v1.11 Mouse [Logitech USB Optical Mouse] on usb-3f980000.usb-1.3.3/input0
[   68.910142] usb 1-1.3.4: new low-speed USB device number 9 using dwc_otg
[   69.067151] usb 1-1.3.4: New USB device found, idVendor=046d, idProduct=c31c
[   69.067160] usb 1-1.3.4: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[   69.067164] usb 1-1.3.4: Product: USB Keyboard
[   69.067168] usb 1-1.3.4: Manufacturer: Logitech
[   69.080191] input: Logitech USB Keyboard as /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.3/1-1.3.4/1-1.3.4:1.0/0003:046D:C31C.0005/input/input4
[   69.150865] hid-generic 0003:046D:C31C.0005: input,hidraw1: USB HID v1.10 Keyboard [Logitech USB Keyboard] on usb-3f980000.usb-1.3.4/input0
[   69.161267] input: Logitech USB Keyboard as /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.3/1-1.3.4/1-1.3.4:1.1/0003:046D:C31C.0006/input/input5
[   69.230424] hid-generic 0003:046D:C31C.0006: input,hidraw2: USB HID v1.10 Device [Logitech USB Keyboard] on usb-3f980000.usb-1.3.4/input1
[   78.422006] usb 1-1.3: USB disconnect, device number 7
[   78.422022] usb 1-1.3.3: USB disconnect, device number 8
[   78.531158] usb 1-1.3.4: USB disconnect, device number 9
[   96.382524] usb 1-1.5: new high-speed USB device number 10 using dwc_otg
[   96.514068] usb 1-1.5: New USB device found, idVendor=05e3, idProduct=0608
[   96.514082] usb 1-1.5: New USB device strings: Mfr=0, Product=1, SerialNumber=0
[   96.514092] usb 1-1.5: Product: USB2.0 Hub
[   96.515103] hub 1-1.5:1.0: USB hub found
[   96.515435] hub 1-1.5:1.0: 4 ports detected
[   96.832634] usb 1-1.5.3: new low-speed USB device number 11 using dwc_otg
[   96.969046] usb 1-1.5.3: New USB device found, idVendor=046d, idProduct=c05a
[   96.969059] usb 1-1.5.3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[   96.969068] usb 1-1.5.3: Product: USB Optical Mouse
[   96.969075] usb 1-1.5.3: Manufacturer: Logitech
[   96.975182] input: Logitech USB Optical Mouse as /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.5/1-1.5.3/1-1.5.3:1.0/0003:046D:C05A.0007/input/input6
[   96.975942] hid-generic 0003:046D:C05A.0007: input,hidraw0: USB HID v1.11 Mouse [Logitech USB Optical Mouse] on usb-3f980000.usb-1.5.3/input0
[   97.072794] usb 1-1.5.4: new low-speed USB device number 12 using dwc_otg
[   97.216553] usb 1-1.5.4: New USB device found, idVendor=046d, idProduct=c31c
[   97.216569] usb 1-1.5.4: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[   97.216577] usb 1-1.5.4: Product: USB Keyboard
[   97.216585] usb 1-1.5.4: Manufacturer: Logitech
[   97.225618] input: Logitech USB Keyboard as /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.5/1-1.5.4/1-1.5.4:1.0/0003:046D:C31C.0008/input/input7
[   97.294270] hid-generic 0003:046D:C31C.0008: input,hidraw1: USB HID v1.10 Keyboard [Logitech USB Keyboard] on usb-3f980000.usb-1.5.4/input0
[   97.309427] input: Logitech USB Keyboard as /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.5/1-1.5.4/1-1.5.4:1.1/0003:046D:C31C.0009/input/input8
[   97.373251] hid-generic 0003:046D:C31C.0009: input,hidraw2: USB HID v1.10 Device [Logitech USB Keyboard] on usb-3f980000.usb-1.5.4/input1
pi@raspberrypi:~ $
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://theiotlearninginitiative.gitbook.io/raspberrypi/embedded-linux/initialization/kernel-ring-buffer.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.