> For the complete documentation index, see [llms.txt](https://netsec.nerd-cafe.ir/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://netsec.nerd-cafe.ir/network-administrator/lpic-1/101.1-determine-and-configure-hardware-settings.md). # 101.1 Determine and configure hardware settings This involves working with: * BIOS/UEFI * Boot process * Hardware devices (PCI, USB, CPU info, etc.) * Tools like `lspci`, `lsusb`, `dmesg`, `lsmod`, `modprobe`, etc. ### **Step 1: Understand the Role of BIOS/UEFI** BIOS (Basic Input/Output System) or UEFI (Unified Extensible Firmware Interface) **initializes hardware before the OS starts**. #### Tasks: * Configure boot device order * Enable/disable onboard devices * Manage virtualization support * Check CPU features like Hyper-Threading, VT-x, etc. > You must access BIOS/UEFI before the OS boots (usually by pressing `Del`, `F2`, or `Esc` at boot time). ### **Step 2: View Hardware Information from Within CentOS** #### 2.1 Check CPU Info ```sh [root@nerd-cafe ~]# cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 58 model name : Intel(R) Core(TM) i7-3632QM CPU @ 2.20GHz stepping : 9 microcode : 0x21 cpu MHz : 2195.019 cache size : 6144 KB physical id : 0 siblings : 1 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx rdtscp lm constant_tsc arch_perfmon nopl xtopology tsc_reliable nonstop_tsc eagerfpu pni pclmulqdq ssse3 cx16 pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm ssbd rsb_ctxsw ibrs ibpb stibp fsgsbase tsc_adjust smep arat md_clear spec_ctrl intel_stibp flush_l1d arch_capabilities bogomips : 4390.03 clflush size : 64 cache_alignment : 64 address sizes : 45 bits physical, 48 bits virtual power management: [root@nerd-cafe ~]# ``` #### 2.2 View Memory Info ```sh [root@nerd-cafe ~]# cat /proc/meminfo MemTotal: 995460 kB MemFree: 424448 kB MemAvailable: 432864 kB Buffers: 2108 kB Cached: 149548 kB SwapCached: 0 kB Active: 311924 kB Inactive: 129364 kB Active(anon): 290100 kB Inactive(anon): 25256 kB Active(file): 21824 kB Inactive(file): 104108 kB Unevictable: 0 kB Mlocked: 0 kB SwapTotal: 839676 kB SwapFree: 839676 kB Dirty: 8 kB Writeback: 0 kB AnonPages: 289664 kB Mapped: 58644 kB Shmem: 25724 kB Slab: 57496 kB SReclaimable: 20364 kB SUnreclaim: 37132 kB KernelStack: 4048 kB PageTables: 9304 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 1337404 kB Committed_AS: 968220 kB VmallocTotal: 34359738367 kB VmallocUsed: 180460 kB VmallocChunk: 34359310332 kB Percpu: 33280 kB HardwareCorrupted: 0 kB AnonHugePages: 206848 kB CmaTotal: 0 kB CmaFree: 0 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB DirectMap4k: 73600 kB DirectMap2M: 974848 kB [root@nerd-cafe ~]# ``` #### 2.3 Check Disk Drives ```sh [root@nerd-cafe ~]# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 8G 0 disk ├─sda1 8:1 0 1G 0 part /boot └─sda2 8:2 0 7G 0 part ├─centos-root 253:0 0 6.2G 0 lvm / └─centos-swap 253:1 0 820M 0 lvm [SWAP] sr0 11:0 1 1024M 0 rom [root@nerd-cafe ~]# ``` or use: ```sh [root@nerd-cafe ~]# fdisk -l Disk /dev/sda: 8589 MB, 8589934592 bytes, 16777216 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 Disk label type: dos Disk identifier: 0x000ec008 Device Boot Start End Blocks Id System /dev/sda1 * 2048 2099199 1048576 83 Linux /dev/sda2 2099200 16777215 7339008 8e Linux LVM Disk /dev/mapper/centos-root: 6652 MB, 6652166144 bytes, 12992512 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 Disk /dev/mapper/centos-swap: 859 MB, 859832320 bytes, 1679360 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 [root@nerd-cafe ~]# ``` #### 2.4 View PCI Devices (e.g. network cards, GPUs) ```sh [root@nerd-cafe ~]# lspci 00:00.0 Host bridge: Intel Corporation 440BX/ZX/DX - 82443BX/ZX/DX Host bridge (rev 01) 00:01.0 PCI bridge: Intel Corporation 440BX/ZX/DX - 82443BX/ZX/DX AGP bridge (rev 01) 00:07.0 ISA bridge: Intel Corporation 82371AB/EB/MB PIIX4 ISA (rev 08) 00:07.1 IDE interface: Intel Corporation 82371AB/EB/MB PIIX4 IDE (rev 01) 00:07.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 08) 00:07.7 System peripheral: VMware Virtual Machine Communication Interface (rev 10) 00:0f.0 VGA compatible controller: VMware SVGA II Adapter 00:10.0 SCSI storage controller: Broadcom / LSI 53c1030 PCI-X Fusion-MPT Dual Ultra320 SCSI (rev 01) 00:11.0 PCI bridge: VMware PCI bridge (rev 02) 00:15.0 PCI bridge: VMware PCI Express Root Port (rev 01) 00:15.1 PCI bridge: VMware PCI Express Root Port (rev 01) 00:15.2 PCI bridge: VMware PCI Express Root Port (rev 01) 00:15.3 PCI bridge: VMware PCI Express Root Port (rev 01) 00:15.4 PCI bridge: VMware PCI Express Root Port (rev 01) 00:15.5 PCI bridge: VMware PCI Express Root Port (rev 01) 00:15.6 PCI bridge: VMware PCI Express Root Port (rev 01) 00:15.7 PCI bridge: VMware PCI Express Root Port (rev 01) 00:16.0 PCI bridge: VMware PCI Express Root Port (rev 01) 00:16.1 PCI bridge: VMware PCI Express Root Port (rev 01) 00:16.2 PCI bridge: VMware PCI Express Root Port (rev 01) 00:16.3 PCI bridge: VMware PCI Express Root Port (rev 01) 00:16.4 PCI bridge: VMware PCI Express Root Port (rev 01) 00:16.5 PCI bridge: VMware PCI Express Root Port (rev 01) 00:16.6 PCI bridge: VMware PCI Express Root Port (rev 01) 00:16.7 PCI bridge: VMware PCI Express Root Port (rev 01) 00:17.0 PCI bridge: VMware PCI Express Root Port (rev 01) 00:17.1 PCI bridge: VMware PCI Express Root Port (rev 01) 00:17.2 PCI bridge: VMware PCI Express Root Port (rev 01) 00:17.3 PCI bridge: VMware PCI Express Root Port (rev 01) 00:17.4 PCI bridge: VMware PCI Express Root Port (rev 01) 00:17.5 PCI bridge: VMware PCI Express Root Port (rev 01) 00:17.6 PCI bridge: VMware PCI Express Root Port (rev 01) 00:17.7 PCI bridge: VMware PCI Express Root Port (rev 01) 00:18.0 PCI bridge: VMware PCI Express Root Port (rev 01) 00:18.1 PCI bridge: VMware PCI Express Root Port (rev 01) 00:18.2 PCI bridge: VMware PCI Express Root Port (rev 01) 00:18.3 PCI bridge: VMware PCI Express Root Port (rev 01) 00:18.4 PCI bridge: VMware PCI Express Root Port (rev 01) 00:18.5 PCI bridge: VMware PCI Express Root Port (rev 01) 00:18.6 PCI bridge: VMware PCI Express Root Port (rev 01) 00:18.7 PCI bridge: VMware PCI Express Root Port (rev 01) 02:00.0 USB controller: VMware USB1.1 UHCI Controller 02:01.0 Ethernet controller: Intel Corporation 82545EM Gigabit Ethernet Controller (Copper) (rev 01) 02:02.0 Ethernet controller: Intel Corporation 82545EM Gigabit Ethernet Controller (Copper) (rev 01) 02:04.0 USB controller: VMware USB2 EHCI Controller [root@nerd-cafe ~]# ``` You can install `pciutils` if `lspci` is not found: ```python [root@nerd-cafe ~]# sudo yum install pciutils ``` #### 2.5 View USB Devices ```sh [root@nerd-cafe ~]# lsusb Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 003: ID 0e0f:0002 VMware, Inc. Virtual USB Hub Bus 002 Device 002: ID 0e0f:0003 VMware, Inc. Virtual Mouse Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub [root@nerd-cafe ~]# ``` Install `usbutils` if needed: ```python [root@nerd-cafe ~]# sudo yum install usbutils ``` ### **Step 3: Kernel Messages and dmesg** #### 3.1 View Boot Hardware Messages ```sh [root@nerd-cafe ~]# dmesg | less ``` Useful filters: ```sh [root@nerd-cafe ~]# dmesg | grep -i usb [ 0.442446] ACPI: bus type USB registered [ 0.442463] usbcore: registered new interface driver usbfs [ 0.442471] usbcore: registered new interface driver hub [ 0.442545] usbcore: registered new device driver usb [ 0.885826] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver [ 0.886259] ehci-pci 0000:02:04.0: new USB bus registered, assigned bus number 1 [ 0.893015] ehci-pci 0000:02:04.0: USB 2.0 started, EHCI 1.00 [ 0.893120] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002, bcdDevice= 3.10 [ 0.893122] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 0.893124] usb usb1: Product: EHCI Host Controller [ 0.893126] usb usb1: Manufacturer: Linux 3.10.0-1160.102.1.el7.x86_64 ehci_hcd [ 0.893128] usb usb1: SerialNumber: 0000:02:04.0 [ 0.893244] hub 1-0:1.0: USB hub found [ 0.893469] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver [ 0.893497] uhci_hcd: USB Universal Host Controller Interface driver [ 0.893936] uhci_hcd 0000:02:00.0: new USB bus registered, assigned bus number 2 [ 0.894385] usb usb2: New USB device found, idVendor=1d6b, idProduct=0001, bcdDevice= 3.10 [ 0.894387] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 0.894389] usb usb2: Product: UHCI Host Controller [ 0.894391] usb usb2: Manufacturer: Linux 3.10.0-1160.102.1.el7.x86_64 uhci_hcd [ 0.894392] usb usb2: SerialNumber: 0000:02:00.0 [ 0.894490] hub 2-0:1.0: USB hub found [ 0.894742] usbcore: registered new interface driver usbserial_generic [ 0.894749] usbserial: USB Serial support registered for generic [ 0.901352] usbcore: registered new interface driver usbhid [ 0.901353] usbhid: USB HID core driver [ 1.205798] usb 2-1: new full-speed USB device number 2 using uhci_hcd [ 1.345738] usb 2-1: New USB device found, idVendor=0e0f, idProduct=0003, bcdDevice= 1.03 [ 1.345743] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 1.345746] usb 2-1: Product: VMware Virtual USB Mouse [ 1.345748] usb 2-1: Manufacturer: VMware [ 1.357301] input: VMware VMware Virtual USB Mouse as /devices/pci0000:00/0000:00:11.0/0000:02:00.0/usb2/2-1/2-1:1.0/input/input4 [ 1.357431] hid-generic 0003:0E0F:0003.0001: input,hidraw0: USB HID v1.10 Mouse [VMware VMware Virtual USB Mouse] on usb-0000:02:00.0-1/input0 [ 1.469771] usb 2-2: new full-speed USB device number 3 using uhci_hcd [ 1.610598] usb 2-2: New USB device found, idVendor=0e0f, idProduct=0002, bcdDevice= 1.00 [ 1.610602] usb 2-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 1.610604] usb 2-2: Product: VMware Virtual USB Hub [ 1.610606] usb 2-2: Manufacturer: VMware, Inc. [ 1.618097] hub 2-2:1.0: USB hub found [root@nerd-cafe ~]# ``` or: ```sh [root@nerd-cafe ~]# dmesg | grep -i eth [ 2.556039] e1000 0000:02:01.0 eth0: (PCI:66MHz:32-bit) 00:0c:29:48:46:e1 [ 2.556047] e1000 0000:02:01.0 eth0: Intel(R) PRO/1000 Network Connection [ 2.957370] e1000 0000:02:02.0 eth1: (PCI:66MHz:32-bit) 00:0c:29:48:46:eb [ 2.957376] e1000 0000:02:02.0 eth1: Intel(R) PRO/1000 Network Connection [root@nerd-cafe ~]# ``` This shows how hardware was detected and initialized during boot. ### **Step 4: Kernel Modules (Drivers)** Linux uses **kernel modules** to load drivers dynamically. #### 4.1 List Loaded Kernel Modules ```sh [root@nerd-cafe ~]# lsmod Module Size Used by ip6t_rpfilter 12595 1 ip6t_REJECT 12625 2 nf_reject_ipv6 13717 1 ip6t_REJECT ipt_REJECT 12541 2 nf_reject_ipv4 13373 1 ipt_REJECT xt_conntrack 12760 13 ebtable_nat 12807 1 ebtable_broute 12731 1 bridge 155432 1 ebtable_broute stp 12976 1 bridge llc 14552 2 stp,bridge ip6table_nat 12864 1 nf_conntrack_ipv6 18935 8 nf_defrag_ipv6 35104 1 nf_conntrack_ipv6 nf_nat_ipv6 14131 1 ip6table_nat ip6table_mangle 12700 1 ip6table_security 12710 1 ip6table_raw 12683 1 iptable_nat 12875 1 nf_conntrack_ipv4 19149 7 nf_defrag_ipv4 12729 1 nf_conntrack_ipv4 nf_nat_ipv4 14115 1 iptable_nat nf_nat 26583 2 nf_nat_ipv4,nf_nat_ipv6 iptable_mangle 12695 1 iptable_security 12705 1 iptable_raw 12678 1 nf_conntrack 143411 6 nf_nat,nf_nat_ipv4,nf_nat_ipv6,xt_conntrack,nf_conntrack_ipv4,nf_conntrack_ipv6 ip_set 45799 0 ebtable_filter 12827 1 ebtables 35009 3 ebtable_broute,ebtable_nat,ebtable_filter ip6table_filter 12815 1 ip6_tables 26912 5 ip6table_filter,ip6table_mangle,ip6table_security,ip6table_nat,ip6table_raw iptable_filter 12810 1 iosf_mbi 15582 0 crc32_pclmul 13133 0 ppdev 17671 0 ghash_clmulni_intel 13273 0 aesni_intel 189456 0 lrw 13286 1 aesni_intel gf128mul 15139 1 lrw glue_helper 13990 1 aesni_intel ablk_helper 13597 1 aesni_intel cryptd 21190 3 ghash_clmulni_intel,aesni_intel,ablk_helper vmw_balloon 18094 0 pcspkr 12718 0 joydev 17389 0 sg 40719 0 vmw_vmci 67168 0 i2c_piix4 22401 0 parport_pc 28205 0 parport 46395 2 ppdev,parport_pc ip_tables 27126 5 iptable_security,iptable_filter,iptable_mangle,iptable_nat,iptable_raw xfs 1014152 2 libcrc32c 12644 3 xfs,nf_nat,nf_conntrack sr_mod 22416 0 cdrom 46696 1 sr_mod ata_generic 12923 0 pata_acpi 13053 0 vmwgfx 296089 1 sd_mod 46281 3 crc_t10dif 12912 1 sd_mod drm_kms_helper 186531 1 vmwgfx crct10dif_generic 12647 0 syscopyarea 12529 1 drm_kms_helper sysfillrect 12701 1 drm_kms_helper sysimgblt 12640 1 drm_kms_helper fb_sys_fops 12703 1 drm_kms_helper ttm 100769 1 vmwgfx crct10dif_pclmul 14307 1 crct10dif_common 12595 3 crct10dif_pclmul,crct10dif_generic,crc_t10dif crc32c_intel 22094 1 drm 468454 4 ttm,drm_kms_helper,vmwgfx ata_piix 35052 0 nfit 59735 0 mptspi 22673 2 serio_raw 13434 0 libata 247190 3 pata_acpi,ata_generic,ata_piix scsi_transport_spi 30732 1 mptspi libnvdimm 163620 1 nfit e1000 137624 0 mptscsih 40150 1 mptspi mptbase 106036 2 mptspi,mptscsih drm_panel_orientation_quirks 17180 1 drm dm_mirror 22326 0 dm_region_hash 20813 1 dm_mirror dm_log 18411 2 dm_region_hash,dm_mirror dm_mod 128595 8 dm_log,dm_mirror [root@nerd-cafe ~]# ``` #### 4.2 Load a Kernel Module ```sh [root@nerd-cafe ~]# sudo modprobe ``` **Example:** To load the `e1000e` network driver: ```sh [root@nerd-cafe ~]# sudo modprobe e1000e ``` #### 4.3 Unload a Kernel Module ```sh [root@nerd-cafe ~]# sudo modprobe -r ``` #### 4.4 Check Module Info ```sh [root@nerd-cafe ~]# modinfo e1000e filename: /lib/modules/3.10.0-1160.102.1.el7.x86_64/kernel/drivers/net/ethernet/intel/e1000e/e1000e.ko.xz version: 3.2.6-k license: GPL v2 description: Intel(R) PRO/1000 Network Driver author: Intel Corporation, retpoline: Y rhelversion: 7.9 srcversion: 098ECE9B1EBA1A3C30EA7ED alias: pci:v00008086d000015E2sv*sd*bc*sc*i* ... alias: pci:v00008086d0000105Esv*sd*bc*sc*i* depends: ptp intree: Y vermagic: 3.10.0-1160.102.1.el7.x86_64 SMP mod_unload modversions signer: CentOS Linux kernel signing key sig_key: 56:7C:0A:85:06:C7:C3:00:F0:66:03:5C:EA:63:E5:BA:FD:E2:3F:DA sig_hashalgo: sha256 parm: debug:Debug level (0=none,...,16=all) (int) parm: copybreak:Maximum size of packet that is copied to a new buffer on receive (uint) parm: TxIntDelay:Transmit Interrupt Delay (array of int) parm: TxAbsIntDelay:Transmit Absolute Interrupt Delay (array of int) parm: RxIntDelay:Receive Interrupt Delay (array of int) parm: RxAbsIntDelay:Receive Absolute Interrupt Delay (array of int) parm: InterruptThrottleRate:Interrupt Throttling Rate (array of int) parm: IntMode:Interrupt Mode (array of int) parm: SmartPowerDownEnable:Enable PHY smart power down (array of int) parm: KumeranLockLoss:Enable Kumeran lock loss workaround (array of int) parm: WriteProtectNVM:Write-protect NVM [WARNING: disabling this can lead to corrupted NVM] (array of int) parm: CrcStripping:Enable CRC Stripping, disable if your BMC needs the CRC (array of int) [root@nerd-cafe ~]# ``` ### **Step 5: Configure Modules to Load at Boot** Edit `/etc/modules-load.d/` or use `/etc/modprobe.d/` #### Example: Auto-load `loop` module on boot ```sh [root@nerd-cafe ~]# echo loop | sudo tee /etc/modules-load.d/loop.conf loop [root@nerd-cafe ~]# ``` ### **Step 6: Check and Configure IRQs and DMA (optional for most modern systems)** View interrupt requests (IRQs): ```sh [root@nerd-cafe ~]# cat /proc/interrupts CPU0 0: 112 IO-APIC-edge timer 1: 42 IO-APIC-edge i8042 8: 1 IO-APIC-edge rtc0 9: 0 IO-APIC-fasteoi acpi 12: 127 IO-APIC-edge i8042 14: 0 IO-APIC-edge ata_piix 15: 3131 IO-APIC-edge ata_piix 16: 4715 IO-APIC-fasteoi vmwgfx, ens34 17: 11450 IO-APIC-fasteoi ioc0 18: 65 IO-APIC-fasteoi ehci_hcd:usb1, uhci_hcd:usb2 19: 25454 IO-APIC-fasteoi ens33 24: 0 PCI-MSI-edge PCIe PME, pciehp 25: 0 PCI-MSI-edge PCIe PME, pciehp 26: 0 PCI-MSI-edge PCIe PME, pciehp 27: 0 PCI-MSI-edge PCIe PME, pciehp 28: 0 PCI-MSI-edge PCIe PME, pciehp 29: 0 PCI-MSI-edge PCIe PME, pciehp 30: 0 PCI-MSI-edge PCIe PME, pciehp 31: 0 PCI-MSI-edge PCIe PME, pciehp 32: 0 PCI-MSI-edge PCIe PME, pciehp 33: 0 PCI-MSI-edge PCIe PME, pciehp 34: 0 PCI-MSI-edge PCIe PME, pciehp 35: 0 PCI-MSI-edge PCIe PME, pciehp 36: 0 PCI-MSI-edge PCIe PME, pciehp 37: 0 PCI-MSI-edge PCIe PME, pciehp 38: 0 PCI-MSI-edge PCIe PME, pciehp 39: 0 PCI-MSI-edge PCIe PME, pciehp 40: 0 PCI-MSI-edge PCIe PME, pciehp 41: 0 PCI-MSI-edge PCIe PME, pciehp 42: 0 PCI-MSI-edge PCIe PME, pciehp 43: 0 PCI-MSI-edge PCIe PME, pciehp 44: 0 PCI-MSI-edge PCIe PME, pciehp 45: 0 PCI-MSI-edge PCIe PME, pciehp 46: 0 PCI-MSI-edge PCIe PME, pciehp 47: 0 PCI-MSI-edge PCIe PME, pciehp 48: 0 PCI-MSI-edge PCIe PME, pciehp 49: 0 PCI-MSI-edge PCIe PME, pciehp 50: 0 PCI-MSI-edge PCIe PME, pciehp 51: 0 PCI-MSI-edge PCIe PME, pciehp 52: 0 PCI-MSI-edge PCIe PME, pciehp 53: 0 PCI-MSI-edge PCIe PME, pciehp 54: 0 PCI-MSI-edge PCIe PME, pciehp 55: 0 PCI-MSI-edge PCIe PME, pciehp 56: 0 PCI-MSI-edge vmw_vmci 57: 0 PCI-MSI-edge vmw_vmci NMI: 0 Non-maskable interrupts LOC: 132836 Local timer interrupts SPU: 0 Spurious interrupts PMI: 0 Performance monitoring interrupts IWI: 7203 IRQ work interrupts RTR: 0 APIC ICR read retries RES: 0 Rescheduling interrupts CAL: 0 Function call interrupts TLB: 0 TLB shootdowns TRM: 0 Thermal event interrupts THR: 0 Threshold APIC interrupts DFR: 0 Deferred Error APIC interrupts MCE: 0 Machine check exceptions MCP: 12 Machine check polls ERR: 0 MIS: 0 PIN: 0 Posted-interrupt notification event NPI: 0 Nested posted-interrupt event PIW: 0 Posted-interrupt wakeup event [root@nerd-cafe ~]# ``` Direct memory access (DMA) channels (less relevant on modern systems): ```sh [root@nerd-cafe ~]# cat /proc/dma 4: cascade [root@nerd-cafe ~]# ``` ### **Step 7: Troubleshoot Hardware Detection** * Check `dmesg` for errors. * Use `lspci -v` or `lsusb -v` for detailed info. * If a device is not working, identify its driver and ensure the module is loaded. * Check logs: ```sh [root@nerd-cafe ~]# sudo journalctl -k ``` ### Summary of Important Commands | Command | Description | | ----------------- | -------------------------- | | cat /proc/cpuinfo | View CPU details | | cat /proc/meminfo | View memory usage | | lsblk | List block storage devices | | lspci | List PCI devices | | lsusb | List USB devices | | dmesg | Kernel and boot messages | | lsmod | Show loaded modules | | modprobe | Load/unload kernel modules | | modinfo | View module info | | journalctl -k | Kernel log messages | ### Keywords `BIOS`, `UEFI`, `CPU info`, `memory info`, `lsblk`, `fdisk`, `lspci`, `lsusb`, `dmesg`, `kernel modules`, `lsmod`, `modprobe`, `modinfo`, `CentOS`, `IRQ`, `DMA`, `journalctl`, `hardware detection`, `boot process`, `hardware configuration`, `nerd cafe`