00dbf19c38
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
55 lines
2.1 KiB
Plaintext
55 lines
2.1 KiB
Plaintext
[[makedev-syntax]]
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Makedev syntax documentation
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----------------------------
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The makedev syntax is used across several places in Buildroot to
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define changes to be made for permissions or which device files to
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create and how to create them, in order to avoid to call mkdnod every
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now and then.
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This syntax is derived from the makedev utility, and a more complete
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documentation can be found in the +package/makedevs/README+ file.
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It takes the form of a line for each file, with the following layout:
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|===========================================================
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|name |type |mode |uid |gid |major |minor |start |inc |count
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|===========================================================
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There is a few non-trivial blocks here:
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- +name+ is the path to the file you want to create/modify
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- +type+ is the type of the file, being one of :
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* f: a regular file
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* d: a directory
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* c: a character device file
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* b: a block device file
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* p: a named pipe
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- +mode+, +uid+ and +gid+ are the usual permissions stuff
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- +major+ and +minor+ are here for device files
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- +start+, +inc+ and +count+ are when you want to create a whole batch
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of files, and can be reduced to a loop, beginning at +start+,
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incrementing its counter by +inc+ until it reaches +count+
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Let's say you want to change the permissions of a given file, using
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this syntax, you will need to put:
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-------------------------------------------------------------------
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/usr/bin/foobar f 644 0 0 - - - - -
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-------------------------------------------------------------------
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On the other hand, if you want to create the device file +/dev/hda+
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and the corresponding 15 files for the partitions, you will need for
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+/dev/hda+:
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-------------------------------------------------------------------
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/dev/hda b 640 0 0 3 0 0 0 -
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-------------------------------------------------------------------
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and then for device files corresponding to the partitions of
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+/dev/hda+, +/dev/hdaX+, +X+ ranging from 1 to 15:
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-------------------------------------------------------------------
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/dev/hda b 640 0 0 3 1 1 1 15
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-------------------------------------------------------------------
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