How do you make initramfs Cpio?

How do you make initramfs Cpio?

How to create an initramfs for my system

  1. In the root of your Factory directory, run make menuconfig.
  2. In the menu, set Target Configuration->Build RFS->cpio to y.
  3. If you wish to build the initramfs image into the kernel, set the option Target Configuration->Build RFS->cpio->Build cpio into kernel as initramfs to y.

What is Cpio initramfs?

The basic initramfs is the root filesystem image used for booting the kernel provided as a compressed cpio archive. If an uncompressed cpio archive exists at the start of the initramfs, extract and load the microcode from it to CPU.

How do I enable initramfs?

In the “General setup” menu, scroll down to the “Initial RAM filesystem and RAM disk support” option and activate it. Once the “Initial RAM filesystem and RAM disk support” option is activated, you should see the “Initramfs source file(s)” option appear. Select it.

How do I edit initramfs?

To modify an initramfs:

  1. Extract the contents of the cpio. gz archive. mkdir tmp_mnt/ gunzip -c initramfs.cpio.gz | sh -c ‘cd tmp_mnt/ && cpio -i’ cd tmp_mnt/
  2. Make changes to the filesystem.
  3. Repack the filesystem into a cpio. gz archive.

How do I view the contents of a cpio file?

How to List the Files on a Tape ( cpio )

  1. Insert an archive tape into the tape drive.
  2. List the files on the tape using the cpio command. $ cpio -civt < /dev/rmt/ n. -c. Specifies that cpio should read files in ASCII character format. -i.

Is Rootfs a RAM?

Rootfs is a special instance of ramfs (or tmpfs, if that’s enabled), which is always present in 2.6 systems.

What is initrd and vmlinuz in Linux?

vmlinuz is the name of the Linux kernel executable. vmlinux is generally just an intermediate step to producing vmlinuz. initrd: The initial RAM disk (initrd) is an initial root file system that is mounted prior to when the real rootfile system is available.

How do I open a cpio file?

Programs that open CPIO files

  1. File Viewer Plus — Get it from Microsoft. PeaZip. Apache Commons Compress.
  2. Apple Archive Utility. Included with OS. Incredible Bee Archiver. Apache Commons Compress. ditto. The Unarchiver.
  3. Linux. GNU cpio. ditto. Apache Commons Compress.

How use cpio command in Linux?

cpio command in Linux with Examples

  1. Copy-out Mode: Copy files named in name-list to the archive. Syntax: cpio -o < name-list > archive.
  2. Copy-in Mode: Extract files from the archive. Syntax: cpio -i < archive.
  3. Copy-pass Mode: Copy files named in name-list to destination-directory. Syntax:

What does the cpio command do in Linux?

You can use the cpio (copy in and out) command to copy individual files, groups of files, or complete file systems. This section describes how to use the cpio command to copy complete file systems. The cpio command is an archiving program that copies a list of files into a single, large output file.

What does the initramfs stand for in Debian?

The booting in Debian is a two-stage process, involving the initial RAM filesystem (initramfs for short, sometimes it is also referred to as initrd, which stands for initial RAM disk). First, the bootloader loads the kernel and initramfs into memory, and passes the execution control to the kernel.

Is the initrd file a compressed cpio file?

As said, an initramfs image is a compressed cpio archive, although the file name may sometimes be deceiving; sometimes it still has “initrd” in its name, and also many times it does not end in .gz or other suffixes that indicate compression: Now cpio is an ancient (and a bit weird) archive format.

How to unpack the initramfs archive in Debian?

Otherwise, treat the whole initramfs as the basic initramfs. unpack the basic initramfs by treating it as compressed (gzip by default on Debian, LZ4 on Ubuntu) cpio archive into a RAM-based disk. mount and use the RAM-based disk as the initial root filesystem.

How to tell if a file is initrd or initramfs?

In both cases, the image file is compressed (typically with gzip) and the kernel expands and mount it. All the recent Linux distribution that use an initial RAM disk use an initramfs image. initrd is being used less and less. To check if the file you’re interested in is an initrd or an initramfs, you can decompress it and feed it to file:

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