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What is Kbuild and Kconfig?
The Linux kernel config/build system, also known as Kconfig/kbuild, has been around for a long time, ever since the Linux kernel code migrated to Git. config file and the vmlinux/bzImage files are produced, and introduce a smart trick for dependency tracking.
What is select in Kconfig?
select will force a symbol to a value without visiting the dependencies. By abusing select you are able to select a symbol FOO even if FOO depends on BAR that is not set. In general use select only for non-visible symbols (no prompts anywhere) and for symbols with no dependencies.
What is config file in kernel?
The Linux kernel configuration is usually found in the kernel source in the file: /usr/src/linux/. config . make config – starts a character based questions and answer session. make menuconfig – starts a terminal-oriented configuration tool (using ncurses)
What is the use of Menuconfig?
make menuconfig is one of five similar tools that can configure Linux source, a necessary early step needed to compile the source code. make menuconfig , with a menu-driven user interface, allows the user to choose the features of Linux (and other options) that will be compiled.
How do kernel modules work?
Kernel modules are pieces of code that can be loaded and unloaded into the kernel upon demand. They extend the functionality of the kernel without the need to reboot the system. A module can be configured as built-in or loadable. The kernel does not have to rebuild your kernel as often.
What is kernel build?
The infrastructure to manage this—building the kernel image and its modules—is known as the Kernel Build System (kbuild). Config symbols: compilation options that can be used to compile code conditionally in source files and to decide which objects to include in a kernel image or its modules.
What is the difference between Insmod and Modprobe?
4 Answers. modprobe is the intelligent version of insmod . insmod simply adds a module where modprobe looks for any dependency (if that particular module is dependent on any other module) and loads them.
Where is the config file in Linux?
- Generally system/global config is stored somewhere under /etc.
- User-specific config is stored in the user’s home directory, often as a hidden file, sometimes as a hidden directory containing non-hidden files (and possibly more subdirectories).
Where is my kernel config file?
You can look at /proc/config. gz if you’re in luck, it will be there. If you have the kernel source, it’s worth having a look at /arch/arm/configs – most Android kernel’s I’ve seen will have the default config for your CPU and you can start from there.
What is Linux Buildroot?
Buildroot is a set of Makefiles and patches that simplifies and automates the process of building a complete and bootable Linux environment for an embedded system, while using cross-compilation to allow building for multiple target platforms on a single Linux-based development system.
How do modules work in Linux?
Linux modules are lumps of code that can be dynamically linked into the kernel at any point after the system has booted. They can be unlinked from the kernel and removed when they are no longer needed. Mostly Linux kernel modules are device drivers, pseudo-device drivers such as network drivers, or file-systems.