LPIC1 (2) Hardware Information

1. Hardware Information:

Some useful tools to report the information of the hardware and the module such as lsusb, lspci, lsdev and lsmod.

2. USB Information:

We can use lsusb to list the information of the USB devices.

$ lsusb -t

-t option for treelike diagram.

/:  Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 5000M
/:  Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 480M
/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M
    |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/6p, 480M

3. PCI Information:

We can use lspci to list the information of the USB devices.

$ lspci -tvv

-t option for treelike diagram and -vv option for very verbose version.

-[0000:00]-+-00.0  Intel Corporation 2nd Generation Core Processor Family DRAM Controller
           +-01.0-[01]----00.0  NVIDIA Corporation GF108M [GeForce GT 540M]
           +-02.0  Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller
           +-16.0  Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #1
           +-1a.0  Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2
           +-1b.0  Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller
           +-1c.0-[02]----00.0  Qualcomm Atheros AR8151 v2.0 Gigabit Ethernet
           +-1c.1-[03]----00.0  Qualcomm Atheros AR9287 Wireless Network Adapter (PCI-Express)
           +-1c.2-[04]--+-00.0  Realtek Semiconductor Co., Ltd. RTS5209 PCI Express Card Reader
           |            \-00.1  Realtek Semiconductor Co., Ltd. RTS5209 PCI Express Card Reader

4. Device Information:

The lsdev command displays the information about your system’s hardware, such as interrupt, addresses and I/O ports.

$ lsdev | less

Device            DMA   IRQ  I/O Ports
------------------------------------------------
0000:00:02.0                   0000-0000
0000:00:1f.2             31    0000-0000   0000-0000   0000-0000   0000-0000   0000-0000
0000:00:1f.3                   0000-0000
0000:01:00.0                     0000-0000
0000:02:00.0                     0000-0000
acpi                      9 
ACPI                             0000-0000     0000-0000     0000-0000     0000-0000     0000-0000     0000-0000
ahci                             0000-0000     0000-0000     0000-0000    

5. List Module:

A module is dynamically linked into the running kernel when it is loaded.

The modules loaded in the system is recorded in /proc/modules.

$ cat /proc/modules | less

drbg 32768 1 - Live 0x0000000000000000
ansi_cprng 16384 0 - Live 0x0000000000000000
ctr 16384 1 - Live 0x0000000000000000
ccm 20480 1 - Live 0x0000000000000000
rfcomm 69632 2 - Live 0x0000000000000000
vmw_vsock_vmci_transport 32768 0 - Live 0x0000000000000000
vsock 36864 1 vmw_vsock_vmci_transport, Live 0x0000000000000000
vmw_vmci 65536 1 vmw_vsock_vmci_transport, Live 0x0000000000000000
ipt_MASQUERADE 16384 1 - Live 0x0000000000000000
nf_nat_masquerade_ipv4 16384 1 ipt_MASQUERADE, Live 0x0000000000000000
xfrm_user 32768 1 - Live 0x0000000000000000
xfrm_algo 16384 1 xfrm_user, Live 0x0000000000000000

For each kernel module loaded, the lsmod displays its name, size, use count, and a list of other referring modules.

$ lsmod | less

Module                  Size  Used by
drbg                   32768  1
ansi_cprng             16384  0
ctr                    16384  1
ccm                    20480  1
rfcomm                 69632  2
vmw_vsock_vmci_transport    32768  0
vsock                  36864  1 vmw_vsock_vmci_transport
vmw_vmci               65536  1 vmw_vsock_vmci_transport
ipt_MASQUERADE         16384  1
nf_nat_masquerade_ipv4    16384  1 ipt_MASQUERADE

6. Insert Module:

The insmod command is used to insert the module.

Tipically, one module depends on other modules. For example, module A is depend on the module B and C. Before we inserting the module A, we must insert the module B and C first. The insmod command would not check the dependency automatically. Using the modprobe command instead of using insmod command to automatically determine these dependencies and it would install the prerequisite modules.

$ insmod <module name>

$? would report the status code of last command. echo $? return 0 for success.

$ echo $?

7. Remove Module:

The rmmod command can be used to remove the module which is not used in the system.

$ rmmod 
$ rmmod -a 

-a option for all modules which is not used in the system.

8. Module Information:

Display the information of the module.

• -a: display the module’s author.<-li>
• -d: display the module’s description.
• -p: display the typed parameters that a module supports.

$ cd /lib/modules/4.4.0-119-generic/kernel/drivers/usb/class
$ modinfo -d usblp.ko
$ modinfo -a usblp.ko
$ modinfo -p usblp.ko

9. Module Probe:

The modprobe command determines prerequisite relationships between modules by reading modules.dep at the top of the module directory hierarchy. If the module is dependent upon other modules, they will be loaded first.

$ modprobe <module name> # insert a module
$ modprobe -r <module name1> <module name2> # remove the modules

Reference

[1] Adam Haeder, Stephen Addison Schneiter, Bruno Gomes Pessanha, and James Stanger , LPI Linux Certification in a nutshell (3rd), O’Reilly Media (2010)