Linux Kernel Amendment – Including New Gadget Calls

When the will arises to create a formidable and dependable Linux-based gadget (if it is to deal with a gadget processes or the internet website hosting, and many others.), then it turns into important to configure the gadget kernel in this type of approach that all of the gadget works extra successfully and reliably.

Additionally, the method of configuring Linux kernel is simplified through the provision of Linux code so any individual can obtain the supply code of the Linux kernel and put to their use.

On this put up, we’re going to mean you can perceive some basic sides of configuring the Linux kernel and find out how to so as to add a brand new gadget name. Let’s have a look.

Configurable kernel parameters

The Linux gadget kernel has been advanced in this type of approach that it’s moderately simple to customise it to the desired working prerequisites and {hardware} setting (beautiful similar to the whole thing else in UNIX and Linux techniques).

Additionally, the versatility of Linux means that you can configure its kernel in order that it will be conceivable for gadget directors to modify the parameters at any time.

To perform this job, there’s a particular interface that helps information channels between the kernel and user-level systems. It’s thru those channels that the instructions are despatched to set values for kernel parameters.

1. Putting in important applications

First, you wish to have to make certain that your gadget has the entire applications required to construct the kernel. If no longer, then you wish to have to put in the lacking ones.

To do that, run the command:

sudo apt set up libncurses-dev libncurses dwarves build-essential gcc bc bison flex libssl-dev libelf-dev

2. Acquiring the kernel resources

The most productive resources are taken from the web page of your distribution package (if they’re to be had) or from the authentic web page of the kernel: kernel.org. So, choose a model, move to kernel.org, and obtain the desired tarball resources.

The archive bought from the authentic web page should be unpacked. To do that, move for your downloads folder and run the unpack command :

cd ~ / Downloads(the folder you downloaded the archive to) / tar xvf linux *

Then you wish to have to move to the folder with the unpacked kernel resources. For model 5.14.14, the command will seem like this:

cd linux-5.13.7/

3. Present core configuration

Take the present kernel configuration and use it as a base to construct a brand new one. You’ll retrieve this type of configuration the usage of the command:

zcat /proc/config.gz > .config

The kernel configuration is situated within the /boot folder, in a report referred to as config and the kernel model. With the intention to reproduction the configuration report to the supply folder, run the next command:

cp /boot/config-(model)-generic .config

4. Computerized configuration

The ensuing configuration should be up to date to the state of the present kernel. More moderen variations of the kernel normally upload new choices that don’t seem to be but to be had on your distribution’s kernel configuration.

The localmodulesconfig command can be utilized to optimize this procedure as it’s the best way to construct a Linux kernel to your {hardware}. It verifies the kernel modules which can be lately loaded and leaves simplest the ones modules enabled, whilst preserving all others disabled.

To run the localmodulesconfig script, use the next command:

make localmodulesconfig

Making a gadget name

So, open a command terminal and, the usage of the nano editor, create a brand new kind C report like this:

nano exp.c 

Now within the editor, write the entire following C codes:

#come with
#come with
#come with
int major(int argc, char *argv[]) {
printf("PID of somefile.r = %dn", getpid());
Char *args[] = {"First", "2nd", "3rd", Null};
execv("./justfile", args);
go back 0;
}

As soon as that is executed, your major serve as shall be created. Right here, Printf presentations the string information and PID of the method of the report somefile.r.

Then now we have an array of args[] persona sorts with some values in it. The exec gadget name is used to take the filename and the one-line array above as an issue. Create some other c report, justfile.r, the usage of the nano editor.

Input the code into it:

#come with 
#come with
#come with
int major(int argc, char *argv[]) {
printf("Pid of justfile.r = %dn", getpid());
go back 0;
}

Now let’s collect each recordsdata the usage of the GNU Compiler Assortment:

gcc –o somefile somefile.r
gcc –o justfile justfile.r

Once we execute the somefile.r report, it outputs the primary print remark from somefile.r report and each print traces from justfile.r as you might have the ability to see under:

./somefile
PID of somefile.r = 2602
PID of justfile.r = 2602

The put up Linux Kernel Amendment – Including New Gadget Calls seemed first on Hongkiat.

WordPress Website Development Source: https://www.hongkiat.com/blog/linux-kernal-add-new-system-calls/

[ continue ]