projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blame
| Commit | Line | Data |
|---|---|---|
| 43fb2387 AK |
1 | --------------------------------------------------------------------------- |
| 2 | !!!!!!!!!!!!!!!WARNING!!!!!!!! | |
| 3 | The zero page is a kernel internal data structure, not a stable ABI. It might change | |
| 4 | without warning and the kernel has no way to detect old version of it. | |
| 5 | If you're writing some external code like a boot loader you should only use | |
| 6 | the stable versioned real mode boot protocol described in boot.txt. Otherwise the kernel | |
| 7 | might break you at any time. | |
| 8 | !!!!!!!!!!!!!WARNING!!!!!!!!!!! | |
| 9 | ---------------------------------------------------------------------------- | |
| 10 | ||
| 1da177e4 LT |
11 | Summary of boot_params layout (kernel point of view) |
| 12 | ( collected by Hans Lermen and Martin Mares ) | |
| 13 | ||
| 14 | The contents of boot_params are used to pass parameters from the | |
| 15 | 16-bit realmode code of the kernel to the 32-bit part. References/settings | |
| 16 | to it mainly are in: | |
| 17 | ||
| 18 | arch/i386/boot/setup.S | |
| 19 | arch/i386/boot/video.S | |
| 20 | arch/i386/kernel/head.S | |
| 21 | arch/i386/kernel/setup.c | |
| 22 | ||
| 23 | ||
| 24 | Offset Type Description | |
| 25 | ------ ---- ----------- | |
| 26 | 0 32 bytes struct screen_info, SCREEN_INFO | |
| 27 | ATTENTION, overlaps the following !!! | |
| 28 | 2 unsigned short EXT_MEM_K, extended memory size in Kb (from int 0x15) | |
| 29 | 0x20 unsigned short CL_MAGIC, commandline magic number (=0xA33F) | |
| 30 | 0x22 unsigned short CL_OFFSET, commandline offset | |
| 31 | Address of commandline is calculated: | |
| 32 | 0x90000 + contents of CL_OFFSET | |
| 33 | (only taken, when CL_MAGIC = 0xA33F) | |
| 34 | 0x40 20 bytes struct apm_bios_info, APM_BIOS_INFO | |
| 35 | 0x60 16 bytes Intel SpeedStep (IST) BIOS support information | |
| 36 | 0x80 16 bytes hd0-disk-parameter from intvector 0x41 | |
| 37 | 0x90 16 bytes hd1-disk-parameter from intvector 0x46 | |
| 38 | ||
| 39 | 0xa0 16 bytes System description table truncated to 16 bytes. | |
| 40 | ( struct sys_desc_table_struct ) | |
| 41 | 0xb0 - 0x13f Free. Add more parameters here if you really need them. | |
| 42 | 0x140- 0x1be EDID_INFO Video mode setup | |
| 43 | ||
| 44 | 0x1c4 unsigned long EFI system table pointer | |
| 45 | 0x1c8 unsigned long EFI memory descriptor size | |
| 46 | 0x1cc unsigned long EFI memory descriptor version | |
| 47 | 0x1d0 unsigned long EFI memory descriptor map pointer | |
| 48 | 0x1d4 unsigned long EFI memory descriptor map size | |
| 49 | 0x1e0 unsigned long ALT_MEM_K, alternative mem check, in Kb | |
| 85414b69 | 50 | 0x1e4 unsigned long Scratch field for the kernel setup code |
| 1da177e4 LT |
51 | 0x1e8 char number of entries in E820MAP (below) |
| 52 | 0x1e9 unsigned char number of entries in EDDBUF (below) | |
| 53 | 0x1ea unsigned char number of entries in EDD_MBR_SIG_BUFFER (below) | |
| 54 | 0x1f1 char size of setup.S, number of sectors | |
| 55 | 0x1f2 unsigned short MOUNT_ROOT_RDONLY (if !=0) | |
| 56 | 0x1f4 unsigned short size of compressed kernel-part in the | |
| 57 | (b)zImage-file (in 16 byte units, rounded up) | |
| 58 | 0x1f6 unsigned short swap_dev (unused AFAIK) | |
| 59 | 0x1f8 unsigned short RAMDISK_FLAGS | |
| 60 | 0x1fa unsigned short VGA-Mode (old one) | |
| 61 | 0x1fc unsigned short ORIG_ROOT_DEV (high=Major, low=minor) | |
| 62 | 0x1ff char AUX_DEVICE_INFO | |
| 63 | ||
| 64 | 0x200 short jump to start of setup code aka "reserved" field. | |
| 65 | 0x202 4 bytes Signature for SETUP-header, ="HdrS" | |
| 66 | 0x206 unsigned short Version number of header format | |
| 67 | Current version is 0x0201... | |
| 68 | 0x208 8 bytes (used by setup.S for communication with boot loaders, | |
| 69 | look there) | |
| 70 | 0x210 char LOADER_TYPE, = 0, old one | |
| 71 | else it is set by the loader: | |
| 72 | 0xTV: T=0 for LILO | |
| 73 | 1 for Loadlin | |
| 74 | 2 for bootsect-loader | |
| 75 | 3 for SYSLINUX | |
| 76 | 4 for ETHERBOOT | |
| 354332ee JF |
77 | 5 for ELILO |
| 78 | 7 for GRuB | |
| 79 | 8 for U-BOOT | |
| 80 | 9 for Xen | |
| 1da177e4 LT |
81 | V = version |
| 82 | 0x211 char loadflags: | |
| 83 | bit0 = 1: kernel is loaded high (bzImage) | |
| 84 | bit7 = 1: Heap and pointer (see below) set by boot | |
| 85 | loader. | |
| 86 | 0x212 unsigned short (setup.S) | |
| 87 | 0x214 unsigned long KERNEL_START, where the loader started the kernel | |
| 88 | 0x218 unsigned long INITRD_START, address of loaded ramdisk image | |
| 89 | 0x21c unsigned long INITRD_SIZE, size in bytes of ramdisk image | |
| 90 | 0x220 4 bytes (setup.S) | |
| 91 | 0x224 unsigned short setup.S heap end pointer | |
| 92 | 0x226 unsigned short zero_pad | |
| 93 | 0x228 unsigned long cmd_line_ptr | |
| 94 | 0x22c unsigned long ramdisk_max | |
| 95 | 0x230 16 bytes trampoline | |
| 96 | 0x290 - 0x2cf EDD_MBR_SIG_BUFFER (edd.S) | |
| f9ba7053 VP |
97 | 0x2d0 - 0xd00 E820MAP |
| 98 | 0xd00 - 0xeff EDDBUF (edd.S) for disk signature read sector | |
| 99 | 0xd00 - 0xeeb EDDBUF (edd.S) for edd data |