linux.h
1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 3 /* 4 * Linux/i386 loader 5 * Supports bzImage, zImage and Image format. 6 * 7 * Based on work by Steve Gehlbach. 8 * Portions are taken from mkelfImage. 9 * 10 * 2003-09 by SONE Takeshi 11 */ 12 13 #include <stdint.h> 14 #include "linux_trampoline.h" 15 16 typedef uint8_t u8; 17 typedef uint16_t u16; 18 typedef uint32_t u32; 19 typedef uint64_t u64; 20 21 #define E820MAX 32 /* number of entries in E820MAP */ 22 struct e820entry { 23 u64 addr; /* start of memory segment */ 24 u64 size; /* size of memory segment */ 25 u32 type; /* type of memory segment */ 26 #define E820_RAM 1 27 #define E820_RESERVED 2 28 #define E820_ACPI 3 /* usable as RAM once ACPI tables have been read */ 29 #define E820_NVS 4 30 } __packed; 31 32 /* The header of Linux/i386 kernel */ 33 struct linux_header { 34 u8 reserved1[0x1f1]; /* 0x000 */ 35 u8 setup_sects; /* 0x1f1 */ 36 u16 root_flags; /* 0x1f2 */ 37 u32 syssize; /* 0x1f4 (2.04+) */ 38 u8 reserved2[2]; /* 0x1f8 */ 39 u16 vid_mode; /* 0x1fa */ 40 u16 root_dev; /* 0x1fc */ 41 u16 boot_sector_magic; /* 0x1fe */ 42 /* 2.00+ */ 43 u8 reserved3[2]; /* 0x200 */ 44 u8 header_magic[4]; /* 0x202 */ 45 u16 protocol_version; /* 0x206 */ 46 u32 realmode_swtch; /* 0x208 */ 47 u16 start_sys; /* 0x20c */ 48 u16 kver_addr; /* 0x20e */ 49 u8 type_of_loader; /* 0x210 */ 50 u8 loadflags; /* 0x211 */ 51 u16 setup_move_size; /* 0x212 */ 52 u32 code32_start; /* 0x214 */ 53 u32 ramdisk_image; /* 0x218 */ 54 u32 ramdisk_size; /* 0x21c */ 55 u8 reserved4[4]; /* 0x220 */ 56 /* 2.01+ */ 57 u16 heap_end_ptr; /* 0x224 */ 58 u8 reserved5[2]; /* 0x226 */ 59 /* 2.02+ */ 60 u32 cmd_line_ptr; /* 0x228 */ 61 /* 2.03+ */ 62 u32 initrd_addr_max; /* 0x22c */ 63 /* 2.05+ */ 64 u32 kernel_alignment; /* 0x230 */ 65 u8 relocatable_kernel; /* 0x234 */ 66 u8 min_alignment; /* 0x235 (2.10+) */ 67 u8 reserved6[2]; /* 0x236 */ 68 /* 2.06+ */ 69 u32 cmdline_size; /* 0x238 */ 70 /* 2.07+ */ 71 u32 hardware_subarch; /* 0x23c */ 72 u64 hardware_subarch_data;/* 0x240 */ 73 /* 2.08+ */ 74 u32 payload_offset; /* 0x248 */ 75 u32 payload_length; /* 0x24c */ 76 /* 2.09+ */ 77 u64 setup_data; /* 0x250 */ 78 /* 2.10+ */ 79 u64 pref_address; /* 0x258 */ 80 u32 init_size; /* 0x260 */ 81 } __packed; 82 83 /* Parameters passed to 32-bit part of Linux 84 * This is another view of the structure above.. */ 85 struct linux_params { 86 u8 orig_x; /* 0x00 */ 87 u8 orig_y; /* 0x01 */ 88 u16 ext_mem_k; /* 0x02 -- EXT_MEM_K sits here */ 89 u16 orig_video_page; /* 0x04 */ 90 u8 orig_video_mode; /* 0x06 */ 91 u8 orig_video_cols; /* 0x07 */ 92 u16 unused2; /* 0x08 */ 93 u16 orig_video_ega_bx; /* 0x0a */ 94 u16 unused3; /* 0x0c */ 95 u8 orig_video_lines; /* 0x0e */ 96 u8 orig_video_isVGA; /* 0x0f */ 97 u16 orig_video_points; /* 0x10 */ 98 99 /* VESA graphic mode -- linear frame buffer */ 100 u16 lfb_width; /* 0x12 */ 101 u16 lfb_height; /* 0x14 */ 102 u16 lfb_depth; /* 0x16 */ 103 u32 lfb_base; /* 0x18 */ 104 u32 lfb_size; /* 0x1c */ 105 u16 cl_magic; /* 0x20 */ 106 #define CL_MAGIC_VALUE 0xA33F 107 u16 cl_offset; /* 0x22 */ 108 u16 lfb_linelength; /* 0x24 */ 109 u8 red_size; /* 0x26 */ 110 u8 red_pos; /* 0x27 */ 111 u8 green_size; /* 0x28 */ 112 u8 green_pos; /* 0x29 */ 113 u8 blue_size; /* 0x2a */ 114 u8 blue_pos; /* 0x2b */ 115 u8 rsvd_size; /* 0x2c */ 116 u8 rsvd_pos; /* 0x2d */ 117 u16 vesapm_seg; /* 0x2e */ 118 u16 vesapm_off; /* 0x30 */ 119 u16 pages; /* 0x32 */ 120 u8 reserved4[12]; /* 0x34 -- 0x3f reserved for future expansion */ 121 122 //struct apm_bios_info apm_bios_info; /* 0x40 */ 123 u8 apm_bios_info[0x40]; 124 //struct drive_info_struct drive_info; /* 0x80 */ 125 u8 drive_info[0x20]; 126 //struct sys_desc_table sys_desc_table; /* 0xa0 */ 127 u8 sys_desc_table[0x140]; 128 u32 alt_mem_k; /* 0x1e0 */ 129 u8 reserved5[4]; /* 0x1e4 */ 130 u8 e820_map_nr; /* 0x1e8 */ 131 u8 reserved6[8]; /* 0x1e9 */ 132 /* This next variable is to show where 133 * in this struct the Linux setup_hdr 134 * is located. It does not get filled in. 135 * We may someday find it useful to use 136 * its address. */ 137 u8 setup_hdr; /* 0x1f1 */ 138 u16 mount_root_rdonly; /* 0x1f2 */ 139 u8 reserved7[4]; /* 0x1f4 */ 140 u16 ramdisk_flags; /* 0x1f8 */ 141 #define RAMDISK_IMAGE_START_MASK 0x07FF 142 #define RAMDISK_PROMPT_FLAG 0x8000 143 #define RAMDISK_LOAD_FLAG 0x4000 144 u8 reserved8[2]; /* 0x1fa */ 145 u16 orig_root_dev; /* 0x1fc */ 146 u8 reserved9[1]; /* 0x1fe */ 147 u8 aux_device_info; /* 0x1ff */ 148 u8 reserved10[2]; /* 0x200 */ 149 u8 param_block_signature[4]; /* 0x202 */ 150 u16 param_block_version; /* 0x206 */ 151 u8 reserved11[8]; /* 0x208 */ 152 u8 loader_type; /* 0x210 */ 153 #define LOADER_TYPE_LOADLIN 1 154 #define LOADER_TYPE_BOOTSECT_LOADER 2 155 #define LOADER_TYPE_SYSLINUX 3 156 #define LOADER_TYPE_ETHERBOOT 4 157 #define LOADER_TYPE_KERNEL 5 158 u8 loader_flags; /* 0x211 */ 159 u8 reserved12[2]; /* 0x212 */ 160 u32 kernel_start; /* 0x214 */ 161 u32 initrd_start; /* 0x218 */ 162 u32 initrd_size; /* 0x21c */ 163 u8 reserved12_5[8]; /* 0x220 */ 164 u32 cmd_line_ptr; /* 0x228 */ 165 u32 initrd_addr_max; /* 0x22c */ 166 u32 kernel_alignment; /* 0x230 */ 167 u8 relocatable_kernel; /* 0x234 */ 168 u8 reserved13[0x2b]; /* 0x235 */ 169 u32 init_size; /* 0x260 */ 170 u8 reserved14[0x6c]; /* 0x264 */ 171 struct e820entry e820_map[E820MAX]; /* 0x2d0 */ 172 u8 reserved16[688]; /* 0x550 */ 173 #define COMMAND_LINE_SIZE 256 174 /* Command line is copied here by 32-bit i386/kernel/head.S. 175 * So I will follow the boot protocol, rather than putting it 176 * directly here. --ts1 */ 177 u8 command_line[COMMAND_LINE_SIZE]; /* 0x800 */ 178 u8 reserved17[1792]; /* 0x900 - 0x1000 */ 179 };