0001 What: /sys/kernel/boot_params
0002 Date: December 2013
0003 Contact: Dave Young <dyoung@redhat.com>
0004 Description: The /sys/kernel/boot_params directory contains two
0005 files: "data" and "version" and one subdirectory "setup_data".
0006 It is used to export the kernel boot parameters of an x86
0007 platform to userspace for kexec and debugging purpose.
0008
0009 If there's no setup_data in boot_params the subdirectory will
0010 not be created.
0011
0012 "data" file is the binary representation of struct boot_params.
0013
0014 "version" file is the string representation of boot
0015 protocol version.
0016
0017 "setup_data" subdirectory contains the setup_data data
0018 structure in boot_params. setup_data is maintained in kernel
0019 as a link list. In "setup_data" subdirectory there's one
0020 subdirectory for each link list node named with the number
0021 of the list nodes. The list node subdirectory contains two
0022 files "type" and "data". "type" file is the string
0023 representation of setup_data type. "data" file is the binary
0024 representation of setup_data payload.
0025
0026 The whole boot_params directory structure is like below::
0027
0028 /sys/kernel/boot_params
0029 |__ data
0030 |__ setup_data
0031 | |__ 0
0032 | | |__ data
0033 | | |__ type
0034 | |__ 1
0035 | |__ data
0036 | |__ type
0037 |__ version
0038
0039 Users: Kexec
