/* SPDX-License-Identifier: GPL-2.0-only */ /* * Linux/i386 loader * Supports bzImage, zImage and Image format. * * Based on work by Steve Gehlbach. * Portions are taken from mkelfImage. * * 2003-09 by SONE Takeshi */ #include <stdint.h> #include "linux_trampoline.h" typedef uint8_t u8; typedef uint16_t u16; typedef uint32_t u32; typedef uint64_t u64; #define E820MAX 32 /* number of entries in E820MAP */ struct e820entry { u64 addr; /* start of memory segment */ u64 size; /* size of memory segment */ u32 type; /* type of memory segment */ #define E820_RAM 1 #define E820_RESERVED 2 #define E820_ACPI 3 /* usable as RAM once ACPI tables have been read */ #define E820_NVS 4 }; /* The header of Linux/i386 kernel */ struct linux_header { u8 reserved1[0x1f1]; /* 0x000 */ u8 setup_sects; /* 0x1f1 */ u16 root_flags; /* 0x1f2 */ u32 syssize; /* 0x1f4 (2.04+) */ u8 reserved2[2]; /* 0x1f8 */ u16 vid_mode; /* 0x1fa */ u16 root_dev; /* 0x1fc */ u16 boot_sector_magic; /* 0x1fe */ /* 2.00+ */ u8 reserved3[2]; /* 0x200 */ u8 header_magic[4]; /* 0x202 */ u16 protocol_version; /* 0x206 */ u32 realmode_swtch; /* 0x208 */ u16 start_sys; /* 0x20c */ u16 kver_addr; /* 0x20e */ u8 type_of_loader; /* 0x210 */ u8 loadflags; /* 0x211 */ u16 setup_move_size; /* 0x212 */ u32 code32_start; /* 0x214 */ u32 ramdisk_image; /* 0x218 */ u32 ramdisk_size; /* 0x21c */ u8 reserved4[4]; /* 0x220 */ /* 2.01+ */ u16 heap_end_ptr; /* 0x224 */ u8 reserved5[2]; /* 0x226 */ /* 2.02+ */ u32 cmd_line_ptr; /* 0x228 */ /* 2.03+ */ u32 initrd_addr_max; /* 0x22c */ /* 2.05+ */ u32 kernel_alignment; /* 0x230 */ u8 relocatable_kernel; /* 0x234 */ u8 min_alignment; /* 0x235 (2.10+) */ u8 reserved6[2]; /* 0x236 */ /* 2.06+ */ u32 cmdline_size; /* 0x238 */ /* 2.07+ */ u32 hardware_subarch; /* 0x23c */ u64 hardware_subarch_data;/* 0x240 */ /* 2.08+ */ u32 payload_offset; /* 0x248 */ u32 payload_length; /* 0x24c */ /* 2.09+ */ u64 setup_data; /* 0x250 */ /* 2.10+ */ u64 pref_address; /* 0x258 */ u32 init_size; /* 0x260 */ } __packed; /* Parameters passed to 32-bit part of Linux * This is another view of the structure above.. */ struct linux_params { u8 orig_x; /* 0x00 */ u8 orig_y; /* 0x01 */ u16 ext_mem_k; /* 0x02 -- EXT_MEM_K sits here */ u16 orig_video_page; /* 0x04 */ u8 orig_video_mode; /* 0x06 */ u8 orig_video_cols; /* 0x07 */ u16 unused2; /* 0x08 */ u16 orig_video_ega_bx; /* 0x0a */ u16 unused3; /* 0x0c */ u8 orig_video_lines; /* 0x0e */ u8 orig_video_isVGA; /* 0x0f */ u16 orig_video_points; /* 0x10 */ /* VESA graphic mode -- linear frame buffer */ u16 lfb_width; /* 0x12 */ u16 lfb_height; /* 0x14 */ u16 lfb_depth; /* 0x16 */ u32 lfb_base; /* 0x18 */ u32 lfb_size; /* 0x1c */ u16 cl_magic; /* 0x20 */ #define CL_MAGIC_VALUE 0xA33F u16 cl_offset; /* 0x22 */ u16 lfb_linelength; /* 0x24 */ u8 red_size; /* 0x26 */ u8 red_pos; /* 0x27 */ u8 green_size; /* 0x28 */ u8 green_pos; /* 0x29 */ u8 blue_size; /* 0x2a */ u8 blue_pos; /* 0x2b */ u8 rsvd_size; /* 0x2c */ u8 rsvd_pos; /* 0x2d */ u16 vesapm_seg; /* 0x2e */ u16 vesapm_off; /* 0x30 */ u16 pages; /* 0x32 */ u8 reserved4[12]; /* 0x34 -- 0x3f reserved for future expansion */ //struct apm_bios_info apm_bios_info; /* 0x40 */ u8 apm_bios_info[0x40]; //struct drive_info_struct drive_info; /* 0x80 */ u8 drive_info[0x20]; //struct sys_desc_table sys_desc_table; /* 0xa0 */ u8 sys_desc_table[0x140]; u32 alt_mem_k; /* 0x1e0 */ u8 reserved5[4]; /* 0x1e4 */ u8 e820_map_nr; /* 0x1e8 */ u8 reserved6[8]; /* 0x1e9 */ /* This next variable is to show where * in this struct the Linux setup_hdr * is located. It does not get filled in. * We may someday find it useful to use * its address. */ u8 setup_hdr; /* 0x1f1 */ u16 mount_root_rdonly; /* 0x1f2 */ u8 reserved7[4]; /* 0x1f4 */ u16 ramdisk_flags; /* 0x1f8 */ #define RAMDISK_IMAGE_START_MASK 0x07FF #define RAMDISK_PROMPT_FLAG 0x8000 #define RAMDISK_LOAD_FLAG 0x4000 u8 reserved8[2]; /* 0x1fa */ u16 orig_root_dev; /* 0x1fc */ u8 reserved9[1]; /* 0x1fe */ u8 aux_device_info; /* 0x1ff */ u8 reserved10[2]; /* 0x200 */ u8 param_block_signature[4]; /* 0x202 */ u16 param_block_version; /* 0x206 */ u8 reserved11[8]; /* 0x208 */ u8 loader_type; /* 0x210 */ #define LOADER_TYPE_LOADLIN 1 #define LOADER_TYPE_BOOTSECT_LOADER 2 #define LOADER_TYPE_SYSLINUX 3 #define LOADER_TYPE_ETHERBOOT 4 #define LOADER_TYPE_KERNEL 5 u8 loader_flags; /* 0x211 */ u8 reserved12[2]; /* 0x212 */ u32 kernel_start; /* 0x214 */ u32 initrd_start; /* 0x218 */ u32 initrd_size; /* 0x21c */ u8 reserved12_5[8]; /* 0x220 */ u32 cmd_line_ptr; /* 0x228 */ u32 initrd_addr_max; /* 0x22c */ u32 kernel_alignment; /* 0x230 */ u8 relocatable_kernel; /* 0x234 */ u8 reserved13[0x2b]; /* 0x235 */ u32 init_size; /* 0x260 */ u8 reserved14[0x6c]; /* 0x264 */ struct e820entry e820_map[E820MAX]; /* 0x2d0 */ u8 reserved16[688]; /* 0x550 */ #define COMMAND_LINE_SIZE 256 /* Command line is copied here by 32-bit i386/kernel/head.S. * So I will follow the boot protocol, rather than putting it * directly here. --ts1 */ u8 command_line[COMMAND_LINE_SIZE]; /* 0x800 */ u8 reserved17[1792]; /* 0x900 - 0x1000 */ };