Booting the Linux kernel When your computer's BIOS boots Slax, it actually just runs SYSLINUX boot loader. The boot loader itself is stored either in file isolinux.bin or ldlinux.sys, depending on your boot media - CD/DVD uses isolinux.bin, USB disk or hard drive uses ldlinux.sys. As soon as the SYSLINUX boot loader is executed, it learns what to do next from its configuration file (you guessed it) syslinux.cfg. In Slax, this configuration file contains instructions to show some cool boot logo and optionally provide boot menu if the user hits a key before timeout. When the timeout counter reaches zero or the user exited boot menu, SYSLINUX boot loader loads two files into memory: vmlinuz (Linux kernel) and initrfs.img (base root filesystem). The progress is indicated by continuous stream of dots printed on screen. Once the files are loaded, the vmlinuz binary is executed to start the Linux kernel.

Pre-init Under normal conditions (when a standard Linux distribution is starting from a hard drive), the Linux kernel would mount root filesystem from the hard drive and /sbin/init would be executed as the main process which takes care of system startup. In Slax, the situation is different - there is no hard drive to mount the root filesystem from, yet the kernel surely needs some init process to be started. For that purpose, Slax carries a base filesystem in initrfs.img file - it is a compressed CPIO archive with some directories and files inside, including core Linux tools (commands) and the desired init. So after the Linux kernel has successfully initialized and has a full control of your computer, its last task is to find the mentioned CPIO archive in memory (it was loaded there from file initrfs.img by syslinux boot loader as you surely remember), extract it (into a memory area which acts as a temporary root filesystem, called initramfs) and execute temporary /init process from there.

Slax is a modern, portable, small and fast Linux operating system.

Escaping initramfs At this moment, we have a fully initialized Linux Kernel running, initramfs area in memory is populated by a temporary root filesystem with just the most basic Linux commands, and temporary init just started. Kamus dewan bahasa melayu. Having the temporary root filesystem in initramfs is not ideal, since it doesn't support pivot_root system call - an important operation which will be used later in the boot up process. We need to switch from initramfs to something else.

To do that, the temporary init firstly mounts a tmpfs filesystem over /m, moves all files and directories in there including the init script itself, and uses switch_root to make this tmpfs /m the new root and to restart the init itself from there too. Blue star denotes the directory which is moved.

(tmpfs) ★ / ├─── bin │ ├─── sh │ ├─── mount │ └───. ├─── dev ├─── mnt ├─── memory ├─── proc ├─── sys ├─── init └─── shutdown No matter how strange this whole action looks like (we've ended up with the very same directory structure like before, it seems like no improvement at all), the change is significant. Since now, the temporary root filesystem is on tmpfs instead of initramfs, and thus pivot_root operation will be available when needed in the future. You may be wondering why is the current root filesystem still labeled as temporary. It's because we're still at the very beginning of the construction phase and we'll just build the real root filesystem later, as explained below, by combining Slax compressed data images to AUFS union.