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Dave Young5039e312013-12-20 18:02:21 +08001What: /sys/kernel/boot_params
2Date: December 2013
3Contact: Dave Young <dyoung@redhat.com>
4Description: The /sys/kernel/boot_params directory contains two
5 files: "data" and "version" and one subdirectory "setup_data".
6 It is used to export the kernel boot parameters of an x86
7 platform to userspace for kexec and debugging purpose.
8
9 If there's no setup_data in boot_params the subdirectory will
10 not be created.
11
12 "data" file is the binary representation of struct boot_params.
13
14 "version" file is the string representation of boot
15 protocol version.
16
17 "setup_data" subdirectory contains the setup_data data
18 structure in boot_params. setup_data is maintained in kernel
19 as a link list. In "setup_data" subdirectory there's one
20 subdirectory for each link list node named with the number
21 of the list nodes. The list node subdirectory contains two
22 files "type" and "data". "type" file is the string
23 representation of setup_data type. "data" file is the binary
24 representation of setup_data payload.
25
26 The whole boot_params directory structure is like below:
27 /sys/kernel/boot_params
28 |__ data
29 |__ setup_data
30 | |__ 0
31 | | |__ data
32 | | |__ type
33 | |__ 1
34 | |__ data
35 | |__ type
36 |__ version
37
38Users: Kexec