Man initramfs tools

Show Threads. Show Posts. Each of these will be discussed separately below with the help of an imaginary tool which performs a frobnication of a lvm partition prior to mounting the root partition. Kernel Command Line The root filesystem used by the kernel is specified by the boot loader as always. Determines how long mountroot waits for root to appear. The default is seconds. Optional parameter for NFS root. The boot variable noresume overrides it.

Debug panic sets an timeout on panic. Instead when invoked with an arbitrary argument output is written to console. The default is premount without any arg.

Beware that if both "panic" and "break" are present, initramfs will not spawn any shells but reboot instead. Other scripts are discarded. Hook scripts These are used when an initramfs image is created and not included in the image itself. They can however cause files to be included in the image. Hook scripts are executed under errexit. Thus a hook script can abort the mkinitramfs build on possible errors exitcode! Boot scripts These are included in the initramfs image and normally executed during kernel boot in the early user-space before the root partition has been mounted.

They are executed during generation of the initramfs-image and are responsible for including all the necessary components in the image itself. No guarantees are made as to the order in which the different scripts are executed unless the prereqs are setup in the script. Header In order to support prereqs, each script should begin with the following lines:!

Thus a hook script can abort the mkinitramfs build on possible errors exitcode! These are included in the initramfs image and normally executed during kernel boot in the early user-space before the root partition has been mounted.

They are executed during generation of the initramfs-image and are responsible for including all the necessary components in the image itself.

No guarantees are made as to the order in which the different scripts are executed unless the prereqs are setup in the script. This means that most executables, unless compiled with klibc, will automatically include glibc in the image which will increase its size by several hundred kilobytes.

There are a number of subdirectories to these two directories which control the boot stage at which the scripts are executed. Like for hook scripts, there are no guarantees as to the order in which the different scripts in one subdirectory see "Subdirectories" below are executed.

In order to define a certain order, a similar header as for hook scripts should be used:. It is easy to check the generated initramfs for its content. One may need to double-check if it contains the relevant binaries, libs or modules:. R initramfs. Les logos Developpez. NAME 2. Kernel Command Line 3.

Standard 3. Debug 4. Hook scripts 4. Boot scripts 4. Header 4. Help functions 4. Including binaries 4. Exported variables 5.

Header 5. Help functions 5. Subdirectories 5. Boot parameters 6. Hook script 6. Boot script 6.