bzImage. The bzImage is the compressed kernel image created with command ‘make bzImage’ during kernel compile. It important to note that bzImage is not compressed with bzip2 !! The name bz in bzImage is misleading!! It stands for “Big Zimage”.
What is make bzImage?
“make bzImage” creates a bzip2 compressed kernel image (in arch/<arch>/build/bzImage). The kernel will be smaller, but might take a few seconds to uncompress on slow machines.
What does Vmlinux stand for?
Linux kernel boot and decompression process.
What is a key difference between a zImage and bzImage kernel image?
26 kernel (starts at line 44): Code: Note: the difference between ‘zImage’ files and ‘bzImage’ files is that ‘bzImage’ uses a different layout and a different loading algorithm, and thus has a larger capacity. Both files use gzip compression.
Why is it called vmlinuz?
The kernel binary on the original UNIX as developed at Bell Labs was called unix. … And because the Linux kernel executable was made into a compressed file and compressed files typically have a z or gz extension on Unix-like systems, the name of the compressed kernel executable became vmlinuz.
What is Initrd in Linux?
The initial RAM disk (initrd) is an initial root file system that is mounted prior to when the real root file system is available. The initrd is bound to the kernel and loaded as part of the kernel boot procedure. … In the case of desktop or server Linux systems, the initrd is a transient file system.
How do I extract Vmlinuz?
Extracting the Linux kernel image (vmlinuz)
You will be able to find the extract-linux script at /usr/src/linux-headers-$(uname -r)/scripts/extract-vmlinux . You will be able to find the extract-linux script at /usr/src/kernels/$(uname -r)/scripts/extract-vmlinux .
What is difference between Vmlinux and vmlinuz?
The vmlinux is the uncompressed built kernel, vmlinuz is the compressed one, that has been made bootable. (Note both names vmlinux and vmlinuz look same except for last letter z). Generally, you don’t need to worry about vmlinux, it is just an intermediate step.
What is vmlinuz in Linux?
Vmlinuz file is the name of Linux kernel executable , by other word its a compressed Linux kernel and it is bootable . Vmlinuz is located in /boot directory , it may be the actual kernel executable or a link to the real one , you can use ls -l /boot to know if its a link or not .
What is Squashfs Fileystem Linux?
Squashfs is a compressed read-only file system for Linux. Squashfs compresses files, inodes and directories, and supports block sizes from 4 KiB up to 1 MiB for greater compression. … Squashfs is also the name of free software, licensed under the GPL, for accessing Squashfs filesystems.
How do I create a Vmlinuz file?
In conclusion, you’ll have to use make bzImage . to create the vmlinuz file. Traditionally, when creating a bootable kernel image, the kernel is also compressed using the zlib algorithm, or since Linux 2.6. 30 using LZMA or BZIP2, which requires a very small decompression stub to be included in the resulting image.