1.. SPDX-License-Identifier: GPL-2.0
   4Zero Page
   6The additional fields in struct boot_params as a part of 32-bit boot
   7protocol of kernel. These should be filled by bootloader or 16-bit
   8real-mode setup code of the kernel. References/settings to it mainly
   9are in::
  11  arch/x86/include/uapi/asm/bootparam.h
  13===========     =====   ======================= =================================================
  14Offset/Size     Proto   Name                    Meaning
  16000/040         ALL     screen_info             Text mode or frame buffer information
  17                                                (struct screen_info)
  18040/014         ALL     apm_bios_info           APM BIOS information (struct apm_bios_info)
  19058/008         ALL     tboot_addr              Physical address of tboot shared page
  20060/010         ALL     ist_info                Intel SpeedStep (IST) BIOS support information
  21                                                (struct ist_info)
  22080/010         ALL     hd0_info                hd0 disk parameter, OBSOLETE!!
  23090/010         ALL     hd1_info                hd1 disk parameter, OBSOLETE!!
  240A0/010         ALL     sys_desc_table          System description table (struct sys_desc_table),
  25                                                OBSOLETE!!
  260B0/010         ALL     olpc_ofw_header         OLPC's OpenFirmware CIF and friends
  270C0/004         ALL     ext_ramdisk_image       ramdisk_image high 32bits
  280C4/004         ALL     ext_ramdisk_size        ramdisk_size high 32bits
  290C8/004         ALL     ext_cmd_line_ptr        cmd_line_ptr high 32bits
  30140/080         ALL     edid_info               Video mode setup (struct edid_info)
  311C0/020         ALL     efi_info                EFI 32 information (struct efi_info)
  321E0/004         ALL     alt_mem_k               Alternative mem check, in KB
  331E4/004         ALL     scratch                 Scratch field for the kernel setup code
  341E8/001         ALL     e820_entries            Number of entries in e820_table (below)
  351E9/001         ALL     eddbuf_entries          Number of entries in eddbuf (below)
  361EA/001         ALL     edd_mbr_sig_buf_entries Number of entries in edd_mbr_sig_buffer
  37                                                (below)
  381EB/001         ALL     kbd_status              Numlock is enabled
  391EC/001         ALL     secure_boot             Secure boot is enabled in the firmware
  401EF/001         ALL     sentinel                Used to detect broken bootloaders
  41290/040         ALL     edd_mbr_sig_buffer      EDD MBR signatures
  422D0/A00         ALL     e820_table              E820 memory map table
  43                                                (array of struct e820_entry)
  44D00/1EC         ALL     eddbuf                  EDD data (array of struct edd_info)
  45===========     =====   ======================= =================================================