| 1 | #ifndef _BZIMAGE_H |
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| 2 | #define _BZIMAGE_H |
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| 3 | |
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| 4 | FILE_LICENCE ( GPL2_OR_LATER ); |
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| 5 | |
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| 6 | #include <stdint.h> |
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| 7 | |
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| 8 | /** |
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| 9 | * A bzImage header |
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| 10 | * |
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| 11 | * As documented in Documentation/i386/boot.txt |
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| 12 | */ |
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| 13 | struct bzimage_header { |
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| 14 | /** The size of the setup in sectors |
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| 15 | * |
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| 16 | * If this field contains 0, assume it contains 4. |
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| 17 | */ |
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| 18 | uint8_t setup_sects; |
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| 19 | /** If set, the root is mounted readonly */ |
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| 20 | uint16_t root_flags; |
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| 21 | /** DO NOT USE - for bootsect.S use only */ |
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| 22 | uint16_t syssize; |
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| 23 | /** DO NOT USE - obsolete */ |
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| 24 | uint16_t swap_dev; |
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| 25 | /** DO NOT USE - for bootsect.S use only */ |
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| 26 | uint16_t ram_size; |
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| 27 | /** Video mode control */ |
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| 28 | uint16_t vid_mode; |
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| 29 | /** Default root device number */ |
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| 30 | uint16_t root_dev; |
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| 31 | /** 0xAA55 magic number */ |
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| 32 | uint16_t boot_flag; |
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| 33 | /** Jump instruction */ |
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| 34 | uint16_t jump; |
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| 35 | /** Magic signature "HdrS" */ |
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| 36 | uint32_t header; |
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| 37 | /** Boot protocol version supported */ |
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| 38 | uint16_t version; |
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| 39 | /** Boot loader hook (see below) */ |
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| 40 | uint32_t realmode_swtch; |
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| 41 | /** The load-low segment (0x1000) (obsolete) */ |
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| 42 | uint16_t start_sys; |
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| 43 | /** Pointer to kernel version string */ |
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| 44 | uint16_t kernel_version; |
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| 45 | /** Boot loader identifier */ |
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| 46 | uint8_t type_of_loader; |
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| 47 | /** Boot protocol option flags */ |
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| 48 | uint8_t loadflags; |
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| 49 | /** Move to high memory size (used with hooks) */ |
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| 50 | uint16_t setup_move_size; |
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| 51 | /** Boot loader hook (see below) */ |
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| 52 | uint32_t code32_start; |
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| 53 | /** initrd load address (set by boot loader) */ |
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| 54 | uint32_t ramdisk_image; |
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| 55 | /** initrd size (set by boot loader) */ |
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| 56 | uint32_t ramdisk_size; |
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| 57 | /** DO NOT USE - for bootsect.S use only */ |
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| 58 | uint32_t bootsect_kludge; |
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| 59 | /** Free memory after setup end */ |
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| 60 | uint16_t heap_end_ptr; |
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| 61 | /** Unused */ |
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| 62 | uint16_t pad1; |
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| 63 | /** 32-bit pointer to the kernel command line */ |
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| 64 | uint32_t cmd_line_ptr; |
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| 65 | /** Highest legal initrd address */ |
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| 66 | uint32_t initrd_addr_max; |
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| 67 | /** Physical addr alignment required for kernel */ |
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| 68 | uint32_t kernel_alignment; |
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| 69 | /** Whether kernel is relocatable or not */ |
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| 70 | uint8_t relocatable_kernel; |
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| 71 | /** Unused */ |
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| 72 | uint8_t pad2[3]; |
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| 73 | /** Maximum size of the kernel command line */ |
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| 74 | uint32_t cmdline_size; |
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| 75 | } __attribute__ (( packed )); |
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| 76 | |
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| 77 | /** Offset of bzImage header within kernel image */ |
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| 78 | #define BZI_HDR_OFFSET 0x1f1 |
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| 79 | |
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| 80 | /** bzImage boot flag value */ |
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| 81 | #define BZI_BOOT_FLAG 0xaa55 |
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| 82 | |
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| 83 | /** bzImage magic signature value */ |
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| 84 | #define BZI_SIGNATURE 0x53726448 |
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| 85 | |
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| 86 | /** bzImage boot loader identifier for Etherboot */ |
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| 87 | #define BZI_LOADER_TYPE_ETHERBOOT 0x40 |
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| 88 | |
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| 89 | /** bzImage boot loader identifier for gPXE |
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| 90 | * |
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| 91 | * We advertise ourselves as Etherboot version 6. |
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| 92 | */ |
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| 93 | #define BZI_LOADER_TYPE_GPXE ( BZI_LOADER_TYPE_ETHERBOOT | 0x06 ) |
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| 94 | |
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| 95 | /** bzImage "load high" flag */ |
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| 96 | #define BZI_LOAD_HIGH 0x01 |
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| 97 | |
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| 98 | /** Load address for high-loaded kernels */ |
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| 99 | #define BZI_LOAD_HIGH_ADDR 0x100000 |
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| 100 | |
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| 101 | /** Load address for low-loaded kernels */ |
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| 102 | #define BZI_LOAD_LOW_ADDR 0x10000 |
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| 103 | |
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| 104 | /** bzImage "kernel can use heap" flag */ |
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| 105 | #define BZI_CAN_USE_HEAP 0x80 |
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| 106 | |
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| 107 | /** bzImage special video mode "normal" */ |
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| 108 | #define BZI_VID_MODE_NORMAL 0xffff |
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| 109 | |
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| 110 | /** bzImage special video mode "ext" */ |
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| 111 | #define BZI_VID_MODE_EXT 0xfffe |
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| 112 | |
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| 113 | /** bzImage special video mode "ask" */ |
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| 114 | #define BZI_VID_MODE_ASK 0xfffd |
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| 115 | |
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| 116 | /** bzImage maximum initrd address for versions < 2.03 */ |
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| 117 | #define BZI_INITRD_MAX 0x37ffffff |
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| 118 | |
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| 119 | /** bzImage command-line structure used by older kernels */ |
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| 120 | struct bzimage_cmdline { |
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| 121 | /** Magic signature */ |
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| 122 | uint16_t magic; |
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| 123 | /** Offset to command line */ |
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| 124 | uint16_t offset; |
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| 125 | } __attribute__ (( packed )); |
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| 126 | |
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| 127 | /** Offset of bzImage command-line structure within kernel image */ |
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| 128 | #define BZI_CMDLINE_OFFSET 0x20 |
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| 129 | |
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| 130 | /** bzImage command line present magic marker value */ |
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| 131 | #define BZI_CMDLINE_MAGIC 0xa33f |
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| 132 | |
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| 133 | /** Assumed size of real-mode portion (including .bss) */ |
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| 134 | #define BZI_ASSUMED_RM_SIZE 0x8000 |
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| 135 | |
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| 136 | /** Amount of stack space to provide */ |
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| 137 | #define BZI_STACK_SIZE 0x1000 |
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| 138 | |
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| 139 | /** Maximum size of command line */ |
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| 140 | #define BZI_CMDLINE_SIZE 0x100 |
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| 141 | |
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| 142 | #endif /* _BZIMAGE_H */ |
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