Documentation/ABI/testing/sysfs-kernel-boot_params

   1 What:           /sys/kernel/boot_params
   2 Date:           December 2013
   3 Contact:        Dave Young <dyoung@redhat.com>
   4 Description:    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
  38 Users:          Kexec