0001 .. SPDX-License-Identifier: GPL-2.0
0002
0003 =========
0004 Zero Page
0005 =========
0006 The additional fields in struct boot_params as a part of 32-bit boot
0007 protocol of kernel. These should be filled by bootloader or 16-bit
0008 real-mode setup code of the kernel. References/settings to it mainly
0009 are in::
0010
0011 arch/x86/include/uapi/asm/bootparam.h
0012
0013 =========== ===== ======================= =================================================
0014 Offset/Size Proto Name Meaning
0015
0016 000/040 ALL screen_info Text mode or frame buffer information
0017 (struct screen_info)
0018 040/014 ALL apm_bios_info APM BIOS information (struct apm_bios_info)
0019 058/008 ALL tboot_addr Physical address of tboot shared page
0020 060/010 ALL ist_info Intel SpeedStep (IST) BIOS support information
0021 (struct ist_info)
0022 070/008 ALL acpi_rsdp_addr Physical address of ACPI RSDP table
0023 080/010 ALL hd0_info hd0 disk parameter, OBSOLETE!!
0024 090/010 ALL hd1_info hd1 disk parameter, OBSOLETE!!
0025 0A0/010 ALL sys_desc_table System description table (struct sys_desc_table),
0026 OBSOLETE!!
0027 0B0/010 ALL olpc_ofw_header OLPC's OpenFirmware CIF and friends
0028 0C0/004 ALL ext_ramdisk_image ramdisk_image high 32bits
0029 0C4/004 ALL ext_ramdisk_size ramdisk_size high 32bits
0030 0C8/004 ALL ext_cmd_line_ptr cmd_line_ptr high 32bits
0031 13C/004 ALL cc_blob_address Physical address of Confidential Computing blob
0032 140/080 ALL edid_info Video mode setup (struct edid_info)
0033 1C0/020 ALL efi_info EFI 32 information (struct efi_info)
0034 1E0/004 ALL alt_mem_k Alternative mem check, in KB
0035 1E4/004 ALL scratch Scratch field for the kernel setup code
0036 1E8/001 ALL e820_entries Number of entries in e820_table (below)
0037 1E9/001 ALL eddbuf_entries Number of entries in eddbuf (below)
0038 1EA/001 ALL edd_mbr_sig_buf_entries Number of entries in edd_mbr_sig_buffer
0039 (below)
0040 1EB/001 ALL kbd_status Numlock is enabled
0041 1EC/001 ALL secure_boot Secure boot is enabled in the firmware
0042 1EF/001 ALL sentinel Used to detect broken bootloaders
0043 290/040 ALL edd_mbr_sig_buffer EDD MBR signatures
0044 2D0/A00 ALL e820_table E820 memory map table
0045 (array of struct e820_entry)
0046 D00/1EC ALL eddbuf EDD data (array of struct edd_info)
0047 =========== ===== ======================= =================================================
