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Diffstat (limited to 'Documentation/ABI/testing/sysfs-kernel-boot_params')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-kernel-boot_params | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-kernel-boot_params b/Documentation/ABI/testing/sysfs-kernel-boot_params new file mode 100644 index 000000000..7f9bda453 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-kernel-boot_params @@ -0,0 +1,39 @@ +What: /sys/kernel/boot_params +Date: December 2013 +Contact: Dave Young <dyoung@redhat.com> +Description: The /sys/kernel/boot_params directory contains two + files: "data" and "version" and one subdirectory "setup_data". + It is used to export the kernel boot parameters of an x86 + platform to userspace for kexec and debugging purpose. + + If there's no setup_data in boot_params the subdirectory will + not be created. + + "data" file is the binary representation of struct boot_params. + + "version" file is the string representation of boot + protocol version. + + "setup_data" subdirectory contains the setup_data data + structure in boot_params. setup_data is maintained in kernel + as a link list. In "setup_data" subdirectory there's one + subdirectory for each link list node named with the number + of the list nodes. The list node subdirectory contains two + files "type" and "data". "type" file is the string + representation of setup_data type. "data" file is the binary + representation of setup_data payload. + + The whole boot_params directory structure is like below:: + + /sys/kernel/boot_params + |__ data + |__ setup_data + | |__ 0 + | | |__ data + | | |__ type + | |__ 1 + | |__ data + | |__ type + |__ version + +Users: Kexec |