mirror of
https://salsa.debian.org/kernel-team/initramfs-tools.git
synced 2026-01-26 07:37:54 +00:00
a797b423d2
Parsing uncompressed cpio archives in this shell script requires
running multiple processes for each archive member.
This was not too bad when there were usually only a few microcode
blobs in an uncompressed archive, but now that we put compressed
kernel modules in an uncompressed archive, it became very slow indeed.
Rewrite it in C so that it's acceptably fast.
This should have no functional changes, except that it adds support
for an initramfs with no compressed part.
Fixes: 81fd41f72dd8 ("Put compressed kernel modules and firmware in an uncompressed cpio")
Signed-off-by: Ben Hutchings <benh@debian.org>
67 lines
1.6 KiB
Groff
67 lines
1.6 KiB
Groff
.TH UNMKINITRAMFS 8 "2025/03/20" "initramfs\-tools" "System Administration"
|
|
|
|
.SH NAME
|
|
unmkinitramfs \- extract content from an initramfs image
|
|
|
|
.SH SYNOPSIS
|
|
.B unmkinitramfs
|
|
.RB [ -v ]
|
|
.IR initramfs-file " " directory
|
|
.br
|
|
.BR unmkinitramfs " " -h
|
|
|
|
.SH DESCRIPTION
|
|
The
|
|
.B unmkinitramfs
|
|
command extracts the content of a given initramfs image using
|
|
.B cpio
|
|
and the appropriate decompressor command.
|
|
|
|
The initramfs image may be a single compressed cpio archive, or the
|
|
concatenation of any number of uncompressed cpio archives optionally
|
|
followed by a compressed cpio archive.
|
|
|
|
When the initramfs image includes one or more "early initramfs"
|
|
archives, that is uncompressed archives with microcode or other files
|
|
that the kernel uses directly, these are extracted to sub\-directories
|
|
named "\fBearly\fR", "\fBearly2\fR", etc., and the other archives are
|
|
extracted to a sub\-directory named "\fBmain\fR".
|
|
|
|
In a future version of initramfs\-tools this behaviour may change so
|
|
that all archives are extracted directly into the given directory.
|
|
|
|
.SH OPTIONS
|
|
|
|
.TP
|
|
.B -h
|
|
Display usage information and exit.
|
|
|
|
.TP
|
|
.B -v
|
|
Display verbose messages about extraction.
|
|
|
|
|
|
.SH USAGE EXAMPLES
|
|
|
|
Extract initramfs content of current running kernel:
|
|
|
|
.PP
|
|
.B unmkinitramfs /boot/initrd.img-$(uname -r) initramfs/
|
|
|
|
|
|
.SH BUGS
|
|
.BR unmkinitramfs
|
|
does not support initramfs images with more than one compressed cpio
|
|
archive.
|
|
|
|
.SH AUTHOR
|
|
The initramfs-tools are written by Maximilian Attems <maks@debian.org>
|
|
and numerous others.
|
|
|
|
.SH SEE ALSO
|
|
.BR
|
|
.IR initramfs-tools (7),
|
|
.IR lsinitramfs (8),
|
|
.IR mkinitramfs (8),
|
|
.IR update-initramfs (8).
|