Linux kernel: Difference between revisions

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Created page with "== Configuring the Linux Kernel == see [https://nixos.org/nixos/manual/index.html#sec-kernel-config NixOS Manual "Linux Kernel"]. == Developing Kernel Modules == see [https:/..."
 
imported>Mic92
out-of-tree kernel modules
Line 4: Line 4:
== Developing Kernel Modules ==
== Developing Kernel Modules ==
see [https://nixos.org/nixos/manual/index.html#idm140737316413584 NixOS Manual "Developing kernel modules"]
see [https://nixos.org/nixos/manual/index.html#idm140737316413584 NixOS Manual "Developing kernel modules"]
If you work on an out-of-tree kernel module the workflow could look as follow:
<syntaxHighlight lang="C">
#include <linux/module.h>
#define MODULE_NAME "hello"
static int __init hello_init(void)
{
    printk(KERN_INFO "hello world!");
    return 0;
}
static void __exit hello_cleanup(void) {}
module_init(hello_init);
module_exit(hello_cleanup);
</syntaxHighlight>
<syntaxHighlight lang="console>
$ nix-shell '<nixpkgs>' -A linux.dev
$ make -C $(nix-build -E '(import <nixpkgs> {}).linux.dev' --no-out-link)/lib/modules/*/build M=$(pwd) modules
$ insmod ./hello.ko
$ dmesg | grep hello
[  82.027229] hello world!
</syntaxHighlight>


== make menuconfig ==
== make menuconfig ==

Revision as of 23:07, 1 January 2018

Configuring the Linux Kernel

see NixOS Manual "Linux Kernel".

Developing Kernel Modules

see NixOS Manual "Developing kernel modules"

If you work on an out-of-tree kernel module the workflow could look as follow:

#include <linux/module.h>
#define MODULE_NAME "hello"
static int __init hello_init(void)
{
    printk(KERN_INFO "hello world!");
    return 0;
}
static void __exit hello_cleanup(void) {}
module_init(hello_init);
module_exit(hello_cleanup);
$ nix-shell '<nixpkgs>' -A linux.dev
$ make -C $(nix-build -E '(import <nixpkgs> {}).linux.dev' --no-out-link)/lib/modules/*/build M=$(pwd) modules
$ insmod ./hello.ko
$ dmesg | grep hello
[   82.027229] hello world!

make menuconfig

It is (currently) not possible to run make menuconfig in the checked out linux kernel sources. This is because ncurses is not part of your working environment when you start it with nix-shell '<nixpkgs>' -A linuxPackages.kernel.

This nix-shell hack adds ncurses as a build dependency to the kernel:

$ nix-shell -E 'with import <nixpkgs> {}; linux.overrideAttrs (o: {nativeBuildInputs=o.nativeBuildInputs ++ [ pkgconfig ncurses ];})'
[nix-shell] $ unpackPhase && cd linux-*
[nix-shell] $ make menuconfig

(thanks to sphalerite)