Editing Vmlinux (section)

==Compression==
Traditionally, when creating a bootable [[Kernel (operating system)|kernel image]], the kernel is also [[data compression|compressed]] using [[gzip]], or, since Linux 2.6.30,<ref name="linux-2.6.30_compression">Linux 2.6.30, released the 9th of June 2009, added support to compress the kernel image with the LZMA and bzip2 algorithms [https://kernelnewbies.org/Linux_2_6_30#head-5773b3b80a9c48eca5aae1e45561f9237d493ae1]</ref> using [[LZMA]] or [[bzip2]], which requires a very small [[data compression|decompression]] stub to be included in the resulting image. The stub decompresses the kernel code, on some systems printing dots to the console to indicate progress, and then continues the boot process. Support for [[Lempel–Ziv–Oberhumer|LZO]],<ref>Linux 2.6.33, released on February 24, 2010, added support to compress the kernel image with LZO [https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7dd65feb6c603e13eba501c34c662259ab38e70e]</ref> [[Lempel–Ziv–Markov_chain_algorithm#xz_and_7z_formats|xz]],<ref>Linux 2.6.38, released on March 14, 2011, added support to compress the kernel image with xz [https://kernelnewbies.org/Linux_2_6_38#Core]</ref> [[LZ4 (compression algorithm)|LZ4]]<ref>Linux 3.11, released on September 2, 2013, added support to compress the kernel image with LZ4 [https://kernelnewbies.org/Linux_3.11#Core]</ref> and [[zstd]]<ref>Linux 5.9, released on October 11, 2020, added support to compress the kernel image, [[initrd]] and [[initramfs]] with zstd [https://kernelnewbies.org/Linux_5.9#Support_for_ZSTD_compressed_kernel.2C_ramdisk_and_initramfs]</ref> compression was added later.

The decompression routine is a negligible factor in boot time, and prior to the development of the ''bzImage'', the size constraints of some architectures, notably i386, were extremely limiting, making compression a necessity.

On the [[SPARC]] architecture, the vmlinux file is compressed using simple [[gzip]], because the [[SILO (boot loader)|SILO]] boot loader transparently decompresses gzipped images.

<!-- which convention!? rather "often" or "usually" but there's no convention... -->
The filename of the bootable image is not important, but many popular distributions use ''vmlinuz''.