| Changbin Du | 0c2d363 | 2019-05-08 23:21:22 +0800 | [diff] [blame] | 1 | .. SPDX-License-Identifier: GPL-2.0 |
| 2 | |
| 3 | ========= |
| 4 | Zero Page |
| 5 | ========= |
| 6 | The additional fields in struct boot_params as a part of 32-bit boot |
| 7 | protocol of kernel. These should be filled by bootloader or 16-bit |
| 8 | real-mode setup code of the kernel. References/settings to it mainly |
| 9 | are in:: |
| 10 | |
| 11 | arch/x86/include/uapi/asm/bootparam.h |
| 12 | |
| 13 | =========== ===== ======================= ================================================= |
| 14 | Offset/Size Proto Name Meaning |
| 15 | |
| 16 | 000/040 ALL screen_info Text mode or frame buffer information |
| 17 | (struct screen_info) |
| 18 | 040/014 ALL apm_bios_info APM BIOS information (struct apm_bios_info) |
| 19 | 058/008 ALL tboot_addr Physical address of tboot shared page |
| 20 | 060/010 ALL ist_info Intel SpeedStep (IST) BIOS support information |
| 21 | (struct ist_info) |
| 22 | 080/010 ALL hd0_info hd0 disk parameter, OBSOLETE!! |
| 23 | 090/010 ALL hd1_info hd1 disk parameter, OBSOLETE!! |
| 24 | 0A0/010 ALL sys_desc_table System description table (struct sys_desc_table), |
| 25 | OBSOLETE!! |
| 26 | 0B0/010 ALL olpc_ofw_header OLPC's OpenFirmware CIF and friends |
| 27 | 0C0/004 ALL ext_ramdisk_image ramdisk_image high 32bits |
| 28 | 0C4/004 ALL ext_ramdisk_size ramdisk_size high 32bits |
| 29 | 0C8/004 ALL ext_cmd_line_ptr cmd_line_ptr high 32bits |
| 30 | 140/080 ALL edid_info Video mode setup (struct edid_info) |
| 31 | 1C0/020 ALL efi_info EFI 32 information (struct efi_info) |
| 32 | 1E0/004 ALL alt_mem_k Alternative mem check, in KB |
| 33 | 1E4/004 ALL scratch Scratch field for the kernel setup code |
| 34 | 1E8/001 ALL e820_entries Number of entries in e820_table (below) |
| 35 | 1E9/001 ALL eddbuf_entries Number of entries in eddbuf (below) |
| 36 | 1EA/001 ALL edd_mbr_sig_buf_entries Number of entries in edd_mbr_sig_buffer |
| 37 | (below) |
| 38 | 1EB/001 ALL kbd_status Numlock is enabled |
| 39 | 1EC/001 ALL secure_boot Secure boot is enabled in the firmware |
| 40 | 1EF/001 ALL sentinel Used to detect broken bootloaders |
| 41 | 290/040 ALL edd_mbr_sig_buffer EDD MBR signatures |
| 42 | 2D0/A00 ALL e820_table E820 memory map table |
| 43 | (array of struct e820_entry) |
| 44 | D00/1EC ALL eddbuf EDD data (array of struct edd_info) |
| 45 | =========== ===== ======================= ================================================= |