Documentation/x86/zero-page.txt

   1 The additional fields in struct boot_params as a part of 32-bit boot
   2 protocol of kernel. These should be filled by bootloader or 16-bit
   3 real-mode setup code of the kernel. References/settings to it mainly
   4 are in:
   5
   6   arch/x86/include/uapi/asm/bootparam.h
   7
   8
   9 Offset  Proto   Name            Meaning
  10 /Size
  11
  12 000/040 ALL     screen_info     Text mode or frame buffer information
  13                                 (struct screen_info)
  14 040/014 ALL     apm_bios_info   APM BIOS information (struct apm_bios_info)
  15 058/008 ALL     tboot_addr      Physical address of tboot shared page
  16 060/010 ALL     ist_info        Intel SpeedStep (IST) BIOS support information
  17                                 (struct ist_info)
  18 080/010 ALL     hd0_info        hd0 disk parameter, OBSOLETE!!
  19 090/010 ALL     hd1_info        hd1 disk parameter, OBSOLETE!!
  20 0A0/010 ALL     sys_desc_table  System description table (struct sys_desc_table),
  21                                 OBSOLETE!!
  22 0B0/010 ALL     olpc_ofw_header OLPC's OpenFirmware CIF and friends
  23 0C0/004 ALL     ext_ramdisk_image ramdisk_image high 32bits
  24 0C4/004 ALL     ext_ramdisk_size  ramdisk_size high 32bits
  25 0C8/004 ALL     ext_cmd_line_ptr  cmd_line_ptr high 32bits
  26 140/080 ALL     edid_info       Video mode setup (struct edid_info)
  27 1C0/020 ALL     efi_info        EFI 32 information (struct efi_info)
  28 1E0/004 ALL     alk_mem_k       Alternative mem check, in KB
  29 1E4/004 ALL     scratch         Scratch field for the kernel setup code
  30 1E8/001 ALL     e820_entries    Number of entries in e820_map (below)
  31 1E9/001 ALL     eddbuf_entries  Number of entries in eddbuf (below)
  32 1EA/001 ALL     edd_mbr_sig_buf_entries Number of entries in edd_mbr_sig_buffer
  33                                 (below)
  34 1EB/001 ALL     kbd_status      Numlock is enabled
  35 1EC/001 ALL     secure_boot     Secure boot is enabled in the firmware
  36 1EF/001 ALL     sentinel        Used to detect broken bootloaders
  37 290/040 ALL     edd_mbr_sig_buffer EDD MBR signatures
  38 2D0/A00 ALL     e820_map        E820 memory map table
  39                                 (array of struct e820entry)
  40 D00/1EC ALL     eddbuf          EDD data (array of struct edd_info)