Commit a4798eb4 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Steven Rostedt (VMware)

Documentation: bootconfig: Fix typos in bootconfig documentation

Fix typos in bootconfig.rst according to Randy's suggestions.

Link: http://lkml.kernel.org/r/157949059219.25888.16939971423610233631.stgit@devnote2Suggested-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Acked-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 0947db01
...@@ -11,20 +11,22 @@ Boot Configuration ...@@ -11,20 +11,22 @@ Boot Configuration
Overview Overview
======== ========
The boot configuration is expanding current kernel cmdline to support The boot configuration expands the current kernel command line to support
additional key-value data when boot the kernel in an efficient way. additional key-value data when booting the kernel in an efficient way.
This allows adoministrators to pass a structured-Key config file. This allows administrators to pass a structured-Key config file.
Config File Syntax Config File Syntax
================== ==================
The boot config syntax is a simple structured key-value. Each key consists The boot config syntax is a simple structured key-value. Each key consists
of dot-connected-words, and key and value are connected by "=". The value of dot-connected-words, and key and value are connected by ``=``. The value
has to be terminated by semi-colon (``;``) or newline (``\n``). has to be terminated by semi-colon (``;``) or newline (``\n``).
For array value, array entries are separated by comma (``,``). :: For array value, array entries are separated by comma (``,``). ::
KEY[.WORD[...]] = VALUE[, VALUE2[...]][;] KEY[.WORD[...]] = VALUE[, VALUE2[...]][;]
Unlike the kernel command line syntax, spaces are OK around the comma and ``=``.
Each key word must contain only alphabets, numbers, dash (``-``) or underscore Each key word must contain only alphabets, numbers, dash (``-``) or underscore
(``_``). And each value only contains printable characters or spaces except (``_``). And each value only contains printable characters or spaces except
for delimiters such as semi-colon (``;``), new-line (``\n``), comma (``,``), for delimiters such as semi-colon (``;``), new-line (``\n``), comma (``,``),
...@@ -35,7 +37,7 @@ quotes (``"VALUE"``) or single-quotes (``'VALUE'``) to quote it. Note that ...@@ -35,7 +37,7 @@ quotes (``"VALUE"``) or single-quotes (``'VALUE'``) to quote it. Note that
you can not escape these quotes. you can not escape these quotes.
There can be a key which doesn't have value or has an empty value. Those keys There can be a key which doesn't have value or has an empty value. Those keys
are used for checking the key exists or not (like a boolean). are used for checking if the key exists or not (like a boolean).
Key-Value Syntax Key-Value Syntax
---------------- ----------------
...@@ -63,7 +65,7 @@ at boot time. So you can append similar trees or key-values. ...@@ -63,7 +65,7 @@ at boot time. So you can append similar trees or key-values.
Comments Comments
-------- --------
The config syntax accepts shell-script style comments. The comments start The config syntax accepts shell-script style comments. The comments starting
with hash ("#") until newline ("\n") will be ignored. with hash ("#") until newline ("\n") will be ignored.
:: ::
...@@ -108,7 +110,7 @@ update the boot loader and the kernel image itself. ...@@ -108,7 +110,7 @@ update the boot loader and the kernel image itself.
To do this operation, Linux kernel provides "bootconfig" command under To do this operation, Linux kernel provides "bootconfig" command under
tools/bootconfig, which allows admin to apply or delete the config file tools/bootconfig, which allows admin to apply or delete the config file
to/from initrd image. You can build it by follwoing command:: to/from initrd image. You can build it by the following command::
# make -C tools/bootconfig # make -C tools/bootconfig
...@@ -122,7 +124,7 @@ To remove the config from the image, you can use -d option as below:: ...@@ -122,7 +124,7 @@ To remove the config from the image, you can use -d option as below::
# tools/bootconfig/bootconfig -d /boot/initrd.img-X.Y.Z # tools/bootconfig/bootconfig -d /boot/initrd.img-X.Y.Z
C onfig File Limitation Config File Limitation
====================== ======================
Currently the maximum config size size is 32KB and the total key-words (not Currently the maximum config size size is 32KB and the total key-words (not
...@@ -145,10 +147,10 @@ User can query or loop on key-value pairs, also it is possible to find ...@@ -145,10 +147,10 @@ User can query or loop on key-value pairs, also it is possible to find
a root (prefix) key node and find key-values under that node. a root (prefix) key node and find key-values under that node.
If you have a key string, you can query the value directly with the key If you have a key string, you can query the value directly with the key
using xbc_find_value(). If you want to know what keys exist in the SKC using xbc_find_value(). If you want to know what keys exist in the boot
tree, you can use xbc_for_each_key_value() to iterate key-value pairs. config, you can use xbc_for_each_key_value() to iterate key-value pairs.
Note that you need to use xbc_array_for_each_value() for accessing Note that you need to use xbc_array_for_each_value() for accessing
each arraies value, e.g.:: each array's value, e.g.::
vnode = NULL; vnode = NULL;
xbc_find_value("key.word", &vnode); xbc_find_value("key.word", &vnode);
...@@ -157,8 +159,8 @@ each arraies value, e.g.:: ...@@ -157,8 +159,8 @@ each arraies value, e.g.::
printk("%s ", value); printk("%s ", value);
} }
If you want to focus on keys which has a prefix string, you can use If you want to focus on keys which have a prefix string, you can use
xbc_find_node() to find a node which prefix key words, and iterate xbc_find_node() to find a node by the prefix string, and iterate
keys under the prefix node with xbc_node_for_each_key_value(). keys under the prefix node with xbc_node_for_each_key_value().
But the most typical usage is to get the named value under prefix But the most typical usage is to get the named value under prefix
...@@ -174,8 +176,8 @@ or get the named array under prefix as below:: ...@@ -174,8 +176,8 @@ or get the named array under prefix as below::
This accesses a value of "key.prefix.option" and an array of This accesses a value of "key.prefix.option" and an array of
"key.prefix.array-option". "key.prefix.array-option".
Locking is not needed, since after initialized, the config becomes readonly. Locking is not needed, since after initialization, the config becomes
All data and keys must be copied if you need to modify it. read-only. All data and keys must be copied if you need to modify it.
Functions and structures Functions and structures
......
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