Packing and unpacking initrd - Revision history

Leo at 19:16, 22 November 2021

2021-11-22T19:16:07Z

← Older revision		Revision as of 19:16, 22 November 2021
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			== Determine initrd format ==
	To modify {{code\|initird.img}} or other similar images, first determine the compression method used by the initrd file. Below, we see that it's using gzip which is typical.		To modify {{code\|initird.img}} or other similar images, first determine the compression method used by the initrd file. Below, we see that it's using gzip which is typical.

	{{Highlight		{{Highlight
	\| code = # file initrd.img		\| code = ## Using gzip
			# file initrd.img
	initramfs.gz: gzip compressed data, last modified: Thu Jul 22 04:16:52 2021, max compression, from Unix, original size 46489600		initramfs.gz: gzip compressed data, last modified: Thu Jul 22 04:16:52 2021, max compression, from Unix, original size 46489600

			## ASCII SVR4 archive
			# file initramfs.img
			initramfs.img: ASCII cpio archive (SVR4 with no CRC)
	\| lang = terminal		\| lang = terminal
	}}		}}

	To unpack and extract {{code\|initird.img}}~~, compressed with~~ gzip:		=== Extracting initrd ===

			==== Gzip ====
			To unpack and extract {{code\|initird.img}} using gzip:

	{{Highlight		{{Highlight
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	}}		}}

			==== ASCII cpio archive ====
			To unpack initramfs using ASCII cpio archive that's generated by dracut, use skipcpio.
			{{Highlight
			\| code = # /usr/lib/dracut/skipcpio initramfs.img {{!}} xz -d {{!}}cpio -id
			\| lang = terminal
			}}

			=== Repacking initrd ===
	To re-pack files back into {{code\|initrd.img}} after making your changes:		To re-pack files back into {{code\|initrd.img}} after making your changes:

Leo at 17:36, 9 August 2021

2021-08-09T17:36:17Z

← Older revision		Revision as of 17:36, 9 August 2021
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	modify {{code\|initird.img}} or other similar images		To modify {{code\|initird.img}} or other similar images, first determine the compression method used by the initrd file. Below, we see that it's using gzip which is typical.

	~~To extract~~ {{code~~\|initird~~.img}}:		{{Highlight
	~~<syntaxhighlight~~ lang=~~"bash" line start="1" enclose="div">~~		\| code = # file initrd.img
	~~# Go to an empty directory before extracting the image.~~		initramfs.gz: gzip compressed data, last modified: Thu Jul 22 04:16:52 2021, max compression, from Unix, original size 46489600
	~~mkdir -p /mnt/initrd_extract && cd /mnt/initrd_extract~~		\| lang = terminal
	~~gzip -dc < /path/to/initrd.img \| cpio -i~~		}}
	~~</syntaxhighlight>~~

	To ~~pack files back into~~ {{code\|~~initrd~~.img}}		To unpack and extract {{code\|initird.img}}, compressed with gzip:
	~~<syntaxhighlight lang="bash" line start="1" enclose="div">~~
	~~# Go to the directory containing the contents of the image.~~
	~~cd /mnt/initrd_extract~~
	~~find . \| cpio -o -c \|~~ gzip ~~-9 > /path/to/initrd.img~~
	~~</syntaxhighlight>~~

	~~You may want to run~~ {{code~~\|file~~ /path/to/initrd.img}} ~~in order to determine the exact method of compression. The above commands above assumes {{code~~\|~~cpio + gzip~~}}.		{{Highlight
			\| code = ## Go to an empty directory before extracting the image.
			# mkdir -p /mnt/initrd_extract && cd /mnt/initrd_extract
			# gzip -dc < /path/to/initrd.img {{!}} cpio -i
			\| lang = terminal
			}}

			To re-pack files back into {{code\|initrd.img}} after making your changes:

	{{Navbox Linux}}[[Category:Linux]]		{{Highlight
			\| code = # Go to the directory containing the contents of the image.
			# cd /mnt/initrd_extract
			# find . {{!}} cpio -o -c {{!}} gzip -9 > /path/to/initrd.img
			\| lang = terminal
			}}<br />
			{{Navbox Linux}}
			[[Category:Linux]]

Leo: Leo moved page Pack/Unpack initrd to Packing and unpacking initrd

2021-08-09T17:32:53Z

Leo moved page Pack/Unpack initrd to Packing and unpacking initrd

← Older revision		Revision as of 17:32, 9 August 2021
(No difference)

Leo: Text replacement - "Category:Linux{{Navbox Linux}}" to "{{Navbox Linux}}Category:Linux"

2019-09-01T06:20:56Z

Text replacement - "Category:Linux{{Navbox Linux}}" to "{{Navbox Linux}}Category:Linux"

← Older revision		Revision as of 06:20, 1 September 2019
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	[[Category:Linux]]~~{{Navbox Linux}}~~		{{Navbox Linux}}[[Category:Linux]]

Leo: Text replacement - "{{Navbox Linux}}{{Navbox Linux}}" to "{{Navbox Linux}}"

2019-09-01T05:10:24Z

Text replacement - "{{Navbox Linux}}{{Navbox Linux}}" to "{{Navbox Linux}}"

← Older revision		Revision as of 05:10, 1 September 2019
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	[[Category:Linux]]~~{{Navbox Linux}}~~{{Navbox Linux}}		[[Category:Linux]]{{Navbox Linux}}

Leo: Text replacement - "Category:Linux" to "Category:Linux{{Navbox Linux}}"

2019-09-01T05:07:37Z

Text replacement - "Category:Linux" to "Category:Linux{{Navbox Linux}}"

← Older revision		Revision as of 05:07, 1 September 2019
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	[[Category:Linux]]{{Navbox Linux}}		[[Category:Linux]]{{Navbox Linux}}{{Navbox Linux}}

Leo: Text replacement - "{{Navbox Linux}} {{Navbox Linux}}" to "{{Navbox Linux}}"

2019-09-01T04:50:12Z

Text replacement - "{{Navbox Linux}} {{Navbox Linux}}" to "{{Navbox Linux}}"

← Older revision		Revision as of 04:50, 1 September 2019
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	[[Category:Linux]]{{Navbox Linux}}		[[Category:Linux]]{{Navbox Linux}}
	~~{{Navbox Linux}}~~

Leo: Text replacement - "Category:Linux " to "Category:Linux{{Navbox Linux}} "

2019-09-01T03:53:25Z

Text replacement - "Category:Linux " to "Category:Linux{{Navbox Linux}} "

← Older revision		Revision as of 03:53, 1 September 2019
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	[[Category:Linux]]		[[Category:Linux]]{{Navbox Linux}}
	{{Navbox Linux}}		{{Navbox Linux}}

Leo: Text replacement - "" to "}}"

2017-02-24T19:14:41Z

Text replacement - "</code>" to "}}"

← Older revision		Revision as of 19:14, 24 February 2017
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	modify {{code\|initird.img~~</code>~~ or other similar images		modify {{code\|initird.img}} or other similar images

	To extract {{code\|initird.img~~</code>~~:		To extract {{code\|initird.img}}:
	<syntaxhighlight lang="bash" line start="1" enclose="div">		<syntaxhighlight lang="bash" line start="1" enclose="div">
	# Go to an empty directory before extracting the image.		# Go to an empty directory before extracting the image.
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	</syntaxhighlight>		</syntaxhighlight>

	To pack files back into {{code\|initrd.img~~</code>~~		To pack files back into {{code\|initrd.img}}
	<syntaxhighlight lang="bash" line start="1" enclose="div">		<syntaxhighlight lang="bash" line start="1" enclose="div">
	# Go to the directory containing the contents of the image.		# Go to the directory containing the contents of the image.
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	</syntaxhighlight>		</syntaxhighlight>

	You may want to run {{code\|file /path/to/initrd.img~~</code>~~ in order to determine the exact method of compression. The above commands above assumes {{code\|cpio + gzip~~</code>~~.		You may want to run {{code\|file /path/to/initrd.img}} in order to determine the exact method of compression. The above commands above assumes {{code\|cpio + gzip}}.


	[[Category:Linux]]		[[Category:Linux]]
	{{Navbox Linux}}		{{Navbox Linux}}

Leo: Text replacement - "`" to "{{code|"`


2017-02-24T19:13:11Z
Text replacement - "<code>" to "{{code|"

				
				
				
				
				
				← Older revision
				Revision as of 19:13, 24 February 2017
				
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modify <code>initird.img</code> or other similar images modify {{code|initird.img</code> or other similar images



To extract <code>initird.img</code>: To extract {{code|initird.img</code>:
<syntaxhighlight lang="bash" line start="1" enclose="div"> <syntaxhighlight lang="bash" line start="1" enclose="div">
  # Go to an empty directory before extracting the image.   # Go to an empty directory before extracting the image.
Line 8:
Line 8:
</syntaxhighlight> </syntaxhighlight>



To pack files back into <code>initrd.img</code> To pack files back into {{code|initrd.img</code>
<syntaxhighlight lang="bash" line start="1" enclose="div"> <syntaxhighlight lang="bash" line start="1" enclose="div">
  # Go to the directory containing the contents of the image.   # Go to the directory containing the contents of the image.
Line 15:
Line 15:
</syntaxhighlight> </syntaxhighlight>



You may want to run <code>file /path/to/initrd.img</code> in order to determine the exact method of compression. The above commands above assumes <code>cpio + gzip</code>. You may want to run {{code|file /path/to/initrd.img</code> in order to determine the exact method of compression. The above commands above assumes {{code|cpio + gzip</code>.






[[Category:Linux]] [[Category:Linux]]
{{Navbox Linux}} {{Navbox Linux}}

← Older revision		Revision as of 19:13, 24 February 2017
Line 1:		Line 1:
	modify <code>initird.img</code> or other similar images		modify {{code\|initird.img</code> or other similar images

	To extract <code>initird.img</code>:		To extract {{code\|initird.img</code>:
	<syntaxhighlight lang="bash" line start="1" enclose="div">		<syntaxhighlight lang="bash" line start="1" enclose="div">
	# Go to an empty directory before extracting the image.		# Go to an empty directory before extracting the image.
Line 8:		Line 8:
	</syntaxhighlight>		</syntaxhighlight>

	To pack files back into <code>initrd.img</code>		To pack files back into {{code\|initrd.img</code>
	<syntaxhighlight lang="bash" line start="1" enclose="div">		<syntaxhighlight lang="bash" line start="1" enclose="div">
	# Go to the directory containing the contents of the image.		# Go to the directory containing the contents of the image.
Line 15:		Line 15:
	</syntaxhighlight>		</syntaxhighlight>

	You may want to run <code>file /path/to/initrd.img</code> in order to determine the exact method of compression. The above commands above assumes <code>cpio + gzip</code>.		You may want to run {{code\|file /path/to/initrd.img</code> in order to determine the exact method of compression. The above commands above assumes {{code\|cpio + gzip</code>.


	[[Category:Linux]]		[[Category:Linux]]
	{{Navbox Linux}}		{{Navbox Linux}}