Initramfs init: Difference between revisions

Latest revision as of 05:48, 12 November 2024

mkinitfs is a tool to create initramfs images. Initramfs images are small images which contain a small filesystem with everything required to boot Alpine. For example, when booting a setup with full disk encryption, the initramfs contains the binaries required to prompt for a password and mount the encrypted disk.

Usage

Under a running alpine machine, the following command can be used if for some reason the initramfs has not been created properly for a new kernel.

mkinitfs -c /etc/mkinitfs/mkinitfs.conf -b / <kernelvers>

The script is located in /sbin/ and is created with ash. It expects /lib/modules to be populated with the <kernelvers> listed. For variations on this command (e.g. for chroot) Search "mkinitfs".

initramfs init cmdline options

In addition to the kernel boot parameters are a number of parameters that the init script understands. These are documented in the mkinitfs-bootparam(7) man page.

Although you may specify your own init script when building an initramfs, these parameters allow for extensive control over the initial startup of an Alpine Linux system.

@@ Line 1: / Line 1: @@
-{{draft}}
+[https://gitlab.alpinelinux.org/alpine/mkinitfs '''mkinitfs'''] is a tool to create initramfs images. Initramfs images are small images which contain a small filesystem with everything required to boot Alpine. For example, when booting a setup with [[Setting up encrypted volumes with LUKS|full disk encryption]], the initramfs contains the binaries required to prompt for a password and mount the encrypted disk.
-==Usage==
+== Usage ==
 Under a running alpine machine, the following command can be used if for some reason the initramfs has not been created properly for a new kernel.
-  mkinitfs -c /etc/mkinitfs/mkinitfs.conf -b / <kernelvers>
+  {{cmd|mkinitfs -c /etc/mkinitfs/mkinitfs.conf -b / <kernelvers>}}
-The script is located in /sbin/ and is created with ash. It expects /lib/modules to be populated with the <kernelvers> listed. For variations on this command (e.g. for chroot) Search "mkinitfs".
+The script is located in {{path|/sbin/}} and is created with ash. It expects {{path|/lib/modules}} to be populated with the <code><kernelvers></code> listed. For variations on this command (e.g. for chroot) Search "mkinitfs".
-== initramfs init cmdline options (work in progress) ==
+== initramfs init cmdline options ==
-In addition to the [https://www.kernel.org/doc/html/v4.14/admin-guide/kernel-parameters.html kernel boot parameters] are a number of parameters that the init script understands.
+In addition to the [https://www.kernel.org/doc/html/v4.14/admin-guide/kernel-parameters.html kernel boot parameters] are a number of parameters that the init script understands. These are documented in the <code>mkinitfs-bootparam(7)</code> man page.
 Although you may specify your own init script when building an initramfs, these parameters allow for extensive control over the initial startup of an Alpine Linux system.
-<code>quiet</code> : less verbose init script execution
+== See Also ==
+* [https://wiki.postmarketos.org/wiki/The_initramfs PostmarketOS Wiki]
-<code>debug_init</code> : sets '-x' in the init script and -d for mdev
+* [https://wiki.archlinux.org/title/Arch_boot_process#initramfs ArchWiki boot process]
-<code>chart</code> : Enables bootchartd for measuring system startup speed.
-<code>ip=dhcp</code> : use DHCP for network configuration.
-<code>ip=client-ip:server-ip:gw-ip:netmask:hostname:device:autoconf:dns1:dns2</code> : use static IP configuration, each field is separated by a colon <code>:</code>
-* <code>client-ip</code> ip address of the guest VM where we are going to run the installer
-* <code>server-ip</code> not used, leave blank or fill with <code>none</code>
-* <code>gw-ip</code>     the gateway ip address
-* <code>netmask</code>   the netmask
-* <code>hostname</code>  not used, leave blank or fill with <code>none</code>
-* <code>device</code>    the network interface of the guest VM, default is <code>eth0</code> if left blank
-* <code>autoconf</code>  not used, leave blank or fill with <code>none</code> or <code>off</code>
-* <code>dns1</code>      address of the DNS server
-* <code>dns2</code>      address of the 2nd DNS server
-<code>modloop=URL</code> : the remote location of the image containing kernel's modules, required for LVM and raid setup.
-:The remote location of the <code>modloop</code> image is the same as the kernel and initramfs (see below).
-<code>blacklist=MODULE{,MODULE}</code> : This comma-separated list names kernel modules that modprobe will reject to load.
-<code>alpine_repo=URL</code> : the location of the Alpine repository from which packages are downloaded.
-:For stable release, use <code>http://dl-cdn.alpinelinux.org/alpine/v3.9/main</code>
-:For rolling release, use <code>http://dl-cdn.alpinelinux.org/alpine/edge/main</code>
-<code>ssh_key=URL</code> : the remote location of your SSH public key. It will be added to root's authorized_keys. Also triggers OpenSSH-server to be installed and started.
-<code>apkovl=URL</code> : Unpack the APK Overlay file from this URL. Happens immediately after network is up . This option will set the default  for service install and setup to false. (see .default_boot_services).
-(work in progress)
-* init=
-* init_args=
-* dasd=
-* s390x_net=
-* rootfstype=
-* modules=
-* crytptroot=
-* cryptdm=
-* cryptheader=
-* cryptoffset=
-* cryptokey=
-* nbd=
-* root=
-* resume
-* rootflags
-* usbdelay
-* pkgs=
-* ssh_key=
-* keep_apk_new
-* splash=
-* ...
 [[category:Kernel]]
+[[Category:Booting]]