Linux compiled kernel

To view the kernel:

#uname [OPTION]

[OPTION]

-R Displays the kernel version and the release number.

How user space accesses and monitors the kernel:

/proc

/sys

Pseudo File System:

Many files in the/proc/sys directory are readable and writable.

/sys Some files can be written

To set kernel parameter values:

Temporary effect, restart after the failure:

#echo VALUE >/proc/sys/file

#sysctl-W DIR. File=value

/proc/sys can be ignored in the/proc/sys directory, and the remaining paths are represented by Dir.file.

For example:

#echo 1 >/proc/sys/vm/dorp_caches

#sysctl-W Vm.dorp_caches=1

#sysctl-W kernel.hostname=test.com

#sysctl-W net.ipv4.ip_forward=1

Permanently valid, not immediately effective:

Modify the/etc/sysctl.conf file. After modification, use SYSCTL-P to let the system reread the file for immediate results.

The editing format is as follows:

DIR. File=value

#sysctl [OPTION] DIR. File=value

[OPTION]

-W temporarily changes the value of a parameter.

-p file loads the system parameters from the specified FILE and takes effect immediately. Load from/etc/sysctl.conf if not specified.

-a displays all kernel parameters and their values.

Kernel Module Management:

#lsmod lists the modules and module names that are loaded in the current kernel.

The display format is as follows:

Module name

Size sizes

Information such as used by usage, which file is called.

#modprobe [OPTION] modname loads a module with the name ModName. The dependencies between modules are processed.

[OPTION]

-R Unload Module

#modinfo modname View the module details.

#insmod moddir load module.

#rmmod modname unload the module.

#depmod moddir build dependencies between modules. and saved to the directory.

For example:

#lsmod |grep Floppy

#modproble-R Floppy

#modinf Mii

#insmod/lib/modules/kernel_version/kernel/drivers/net/mii.ko

#rmmod Mii

Features in the kernel, in addition to the core functionality, at compile time, most features have 3 choices:

1. Do not use this feature.

2. Compile into a kernel module.

3. Compile into the kernel.

Compile kernel:

0. Install the development libraries and tools:

#yum Groupinstall "Development Tools" "Development libaries"

1. After the kernel download is complete, the decompression is stored under/USR/SRC. You can create soft links to simplify access.

#tar-xf kernelfile-c/usr/src

/usr/src/kernelversion

#cd/USR/SRC

#ln-S Kernelversion simplename

2. Copy the current kernel's configuration file to the. config file of the kernel to be compiled. This effectively avoids a certain degree of the creation of the. config file because the feature selection is inappropriate or the dependency causes the failure to start, and multiple compilations are repeated.

#cp/boot/config-kernel_version/usr/src/simplename/.config

3. Start compiling:

#cd Simplename

Under the graphical interface:

Need to install the graphical interface Development library.

Used #make Geconfig GNOME environment. GNOME Software Development

#make kconfig KDE environment. KDE Software Development

Text:

#make Menuconfig

which

*: Compile into kernel.

M: Compiling into modules

Null: Do not use this feature.

#make

Install the kernel module #make modules_install.

#make Install

4. Compiling INITRD

Create a initrd file #mkinitrd initrdfile kernelversion.

Common scenarios for compiling kernels:

1. Interrupt during kernel compilation:

Use the screen tool.

2. Compile again after compiling:

Delete the entire folder and unzip it after the compilation.

Or

If necessary, back up the. config file first.

#make clean cleans up the previously compiled two-level module.

#make Mrproper Clean up all the operations that were previously compiled.

This article is from "Small Private blog" blog, please be sure to keep this source http://ggvylf.blog.51cto.com/784661/1614900

Linux compiled kernel