1The additional fields in struct boot_params as a part of 32-bit boot 2protocol of kernel. These should be filled by bootloader or 16-bit 3real-mode setup code of the kernel. References/settings to it mainly 4are in: 5 6 arch/x86/include/asm/bootparam.h 7 8 9Offset Proto Name Meaning 10/Size 11 12000/040 ALL screen_info Text mode or frame buffer information 13 (struct screen_info) 14040/014 ALL apm_bios_info APM BIOS information (struct apm_bios_info) 15058/008 ALL tboot_addr Physical address of tboot shared page 16060/010 ALL ist_info Intel SpeedStep (IST) BIOS support information 17 (struct ist_info) 18080/010 ALL hd0_info hd0 disk parameter, OBSOLETE!! 19090/010 ALL hd1_info hd1 disk parameter, OBSOLETE!! 200A0/010 ALL sys_desc_table System description table (struct sys_desc_table) 210B0/010 ALL olpc_ofw_header OLPC's OpenFirmware CIF and friends 220C0/004 ALL ext_ramdisk_image ramdisk_image high 32bits 230C4/004 ALL ext_ramdisk_size ramdisk_size high 32bits 240C8/004 ALL ext_cmd_line_ptr cmd_line_ptr high 32bits 25140/080 ALL edid_info Video mode setup (struct edid_info) 261C0/020 ALL efi_info EFI 32 information (struct efi_info) 271E0/004 ALL alk_mem_k Alternative mem check, in KB 281E4/004 ALL scratch Scratch field for the kernel setup code 291E8/001 ALL e820_entries Number of entries in e820_map (below) 301E9/001 ALL eddbuf_entries Number of entries in eddbuf (below) 311EA/001 ALL edd_mbr_sig_buf_entries Number of entries in edd_mbr_sig_buffer 32 (below) 331EF/001 ALL sentinel Used to detect broken bootloaders 34290/040 ALL edd_mbr_sig_buffer EDD MBR signatures 352D0/A00 ALL e820_map E820 memory map table 36 (array of struct e820entry) 37D00/1EC ALL eddbuf EDD data (array of struct edd_info) 38