Lines Matching +full:sub +full:- +full:spaces

1 .. SPDX-License-Identifier: GPL-2.0
15 additional key-value data when booting the kernel in an efficient way.
16 This allows administrators to pass a structured-Key config file.
21 The boot config syntax is a simple structured key-value. Each key consists
22 of dot-connected-words, and key and value are connected by ``=``. The value
23 has to be terminated by semi-colon (``;``) or newline (``\n``).
28 Unlike the kernel command line syntax, spaces are OK around the comma and ``=``.
30 Each key word must contain only alphabets, numbers, dash (``-``) or underscore
31 (``_``). And each value only contains printable characters or spaces except
32 for delimiters such as semi-colon (``;``), new-line (``\n``), comma (``,``),
35 If you want to use those delimiters in a value, you can use either double-
36 quotes (``"VALUE"``) or single-quotes (``'VALUE'``) to quote it. Note that
42 Key-Value Syntax
43 ----------------
63 at boot time. So you can append similar trees or key-values.
65 Same-key Values
66 ---------------
68 It is prohibited that two or more values or arrays share a same-key.
72  foo = qux  # !ERROR! we can not re-define same key
92 However, a sub-key and a value can not co-exist under a parent key.
96  foo.bar = value2 # !ERROR! subkey "bar" and value "value1" can NOT co-exist
101 --------
103 The config syntax accepts shell-script style comments. The comments starting
129 /proc/bootconfig is a user-space interface of the boot config.
130 Unlike /proc/cmdline, this file shows the key-value style list.
131 Each key-value pair is shown in each line with following style::
141 checksum and 12-byte magic word as below.
163  # make -C tools/bootconfig
168  # tools/bootconfig/bootconfig -a your-config /boot/initrd.img-X.Y.Z
170 To remove the config from the image, you can use -d option as below::
172  # tools/bootconfig/bootconfig -d /boot/initrd.img-X.Y.Z
180 Currently the maximum config size size is 32KB and the total key-words (not
181 key-value entries) must be under 1024 nodes.
183 more than 2 nodes (a key-word and a value). So theoretically, it will be
184 up to 512 key-value pairs. If keys contains 3 words in average, it can
185 contain 256 key-value pairs. In most cases, the number of config items
197 User can query or loop on key-value pairs, also it is possible to find
198 a root (prefix) key node and find key-values under that node.
202 config, you can use xbc_for_each_key_value() to iterate key-value pairs.
223  xbc_node_for_each_array_value(root, "array-option", value, anode) {
228 "key.prefix.array-option".
231 read-only. All data and keys must be copied if you need to modify it.
237 .. kernel-doc:: include/linux/bootconfig.h
238 .. kernel-doc:: lib/bootconfig.c