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Can I delete initrd IMG?
To free space in /boot we’ll remove an initrd. img file for a suitable old kernel manually, this is necessary due to a kenel packaging bug. If the last command fails due to insufficient disk space in /boot, you have to purge another kernel (e.g. linux-image-4.2.
What is ascii CPIO archive?
Description. A cpio archive consists of one or more concatenated member files. Each member file contains a header optionally followed by file contents as indicated in the header. ASCII archives have totally printable header information; thus, if the files being archived are also ASCII files, the whole archive is ASCII.
What does the initrd.img file contain?
It seems in “recent” kernels the initrd.img file can contain an uncompressed cpio archive (i.e. containing microcode updates) prepended to the (compressed) cpio archive containing the normal initramfs directory tree.
Where can I find the archive format for initramfs?
The complete initramfs archive format is explained in buffer-format.txt, created in usr/gen_init_cpio.c, and extracted in init/initramfs.c. All three together come to less than 26k total of human-readable text. 3) The GNU project standardizing on tar is approximately as relevant as Windows standardizing on zip.
How to repack initramfs.img with Newc format?
Make proper archive with newc format containing kernel/x86/microcode/GenuineIntel.bin: Add gzipped filesystem archive to the proper new_initrd.img: The second command renames the initrd, you specifiy the initrd to use when booting in grub. I suggest you test (boot)the custom initrd before moving or renaming it.
Where to find splitinitramfs function in initrd.img?
, but more precise code for parsing through this sort of initrd.img file can be found in the splitinitramfs () function within the unmkinitramfs command found in the initramfs-tools-core package (e.g. https://git.launchpad.net/ubuntu/+source/initramfs-tools/tree/unmkinitramfs ).