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kabirsaini2011

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About kabirsaini2011

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    Enthusiast
  • Birthday 11/04/1992

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    New Delhi

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  • Your Current Device(s)
    Xolo x900
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    kabirsaini2011
  1. I dont have this device now. It was stolen
  2. well, My mate has some little upgrade. He figured out the stuff and flashed gingerbread back. Now, he is preparing for jellybean.
  3. I have 2 patched full roms
  4. What about JB rom of Moto Razr-i or xolo x1000
  5. try to flash with osdnx and ifwi of x900
  6. Try to flash moto razr-i's jb if u pass
  7. dont use ifwi and osdnx of the tool :P
  8. You are right dude .. Its for signing and going custom ..
  9. u need to load the files first
  10. From Xolo's Service centre.
  11. Hey guys checkout new OFFICIAL xolo x900 and x500 toolkit ... i guess for orange sandiego too!! https://docs.google.com/file/d/0ByqUQKI3yUmFRFhwSWF0NUFlZ0k/edit Credits to Nipun Birla for uploading
  12. [Tool]AIO Tool for San Diego and xolo

    Boot.txt THE LINUX/x86 BOOT PROTOCOL 2 --------------------------- 3 4 On the x86 platform, the Linux kernel uses a rather complicated boot 5 convention. This has evolved partially due to historical aspects, as 6 well as the desire in the early days to have the kernel itself be a 7 bootable image, the complicated PC memory model and due to changed 8 expectations in the PC industry caused by the effective demise of 9 real-mode DOS as a mainstream operating system. 10 11 Currently, the following versions of the Linux/x86 boot protocol exist. 12 13 Old kernels: zImage/Image support only. Some very early kernels 14 may not even support a command line. 15 16 Protocol 2.00: (Kernel 1.3.73) Added bzImage and initrd support, as 17 well as a formalized way to communicate between the 18 boot loader and the kernel. setup.S made relocatable, 19 although the traditional setup area still assumed 20 writable. 21 22 Protocol 2.01: (Kernel 1.3.76) Added a heap overrun warning. 23 24 Protocol 2.02: (Kernel 2.4.0-test3-pre3) New command line protocol. 25 Lower the conventional memory ceiling. No overwrite 26 of the traditional setup area, thus making booting 27 safe for systems which use the EBDA from SMM or 32-bit 28 BIOS entry points. zImage deprecated but still 29 supported. 30 31 Protocol 2.03: (Kernel 2.4.18-pre1) Explicitly makes the highest possible 32 initrd address available to the bootloader. 33 34 Protocol 2.04: (Kernel 2.6.14) Extend the syssize field to four bytes. 35 36 Protocol 2.05: (Kernel 2.6.20) Make protected mode kernel relocatable. 37 Introduce relocatable_kernel and kernel_alignment fields. 38 39 Protocol 2.06: (Kernel 2.6.22) Added a field that contains the size of 40 the boot command line. 41 42 Protocol 2.07: (Kernel 2.6.24) Added paravirtualised boot protocol. 43 Introduced hardware_subarch and hardware_subarch_data 44 and KEEP_SEGMENTS flag in load_flags. 45 46 Protocol 2.08: (Kernel 2.6.26) Added crc32 checksum and ELF format 47 payload. Introduced payload_offset and payload_length 48 fields to aid in locating the payload. 49 50 Protocol 2.09: (Kernel 2.6.26) Added a field of 64-bit physical 51 pointer to single linked list of struct setup_data. 52 53 Protocol 2.10: (Kernel 2.6.31) Added a protocol for relaxed alignment 54 beyond the kernel_alignment added, new init_size and 55 pref_address fields. Added extended boot loader IDs. 56 57 Protocol 2.11: (Kernel 3.6) Added a field for offset of EFI handover 58 protocol entry point. 59 60 Protocol 2.12: (Kernel 3.9) Added the xloadflags field and extension fields 61 to struct boot_params for for loading bzImage and ramdisk 62 above 4G in 64bit. 63 64 **** MEMORY LAYOUT 65 66 The traditional memory map for the kernel loader, used for Image or 67 zImage kernels, typically looks like: 68 69 | | 70 0A0000 +------------------------+ 71 | Reserved for BIOS | Do not use. Reserved for BIOS EBDA. 72 09A000 +------------------------+ 73 | Command line | 74 | Stack/heap | For use by the kernel real-mode code. 75 098000 +------------------------+ 76 | Kernel setup | The kernel real-mode code. 77 090200 +------------------------+ 78 | Kernel boot sector | The kernel legacy boot sector. 79 090000 +------------------------+ 80 | Protected-mode kernel | The bulk of the kernel image. 81 010000 +------------------------+ 82 | Boot loader | <- Boot sector entry point 0000:7C00 83 001000 +------------------------+ 84 | Reserved for MBR/BIOS | 85 000800 +------------------------+ 86 | Typically used by MBR | 87 000600 +------------------------+ 88 | BIOS use only | 89 000000 +------------------------+ 90 91 92 When using bzImage, the protected-mode kernel was relocated to 93 0x100000 ("high memory"), and the kernel real-mode block (boot sector, 94 setup, and stack/heap) was made relocatable to any address between 95 0x10000 and end of low memory. Unfortunately, in protocols 2.00 and 96 2.01 the 0x90000+ memory range is still used internally by the kernel; 97 the 2.02 protocol resolves that problem. 98 99 It is desirable to keep the "memory ceiling" -- the highest point in 100 low memory touched by the boot loader -- as low as possible, since 101 some newer BIOSes have begun to allocate some rather large amounts of 102 memory, called the Extended BIOS Data Area, near the top of low 103 memory. The boot loader should use the "INT 12h" BIOS call to verify 104 how much low memory is available. 105 106 Unfortunately, if INT 12h reports that the amount of memory is too 107 low, there is usually nothing the boot loader can do but to report an 108 error to the user. The boot loader should therefore be designed to 109 take up as little space in low memory as it reasonably can. For 110 zImage or old bzImage kernels, which need data written into the 111 0x90000 segment, the boot loader should make sure not to use memory 112 above the 0x9A000 point; too many BIOSes will break above that point. 113 114 For a modern bzImage kernel with boot protocol version >= 2.02, a 115 memory layout like the following is suggested: 116 117 ~ ~ 118 | Protected-mode kernel | 119 100000 +------------------------+ 120 | I/O memory hole | 121 0A0000 +------------------------+ 122 | Reserved for BIOS | Leave as much as possible unused 123 ~ ~ 124 | Command line | (Can also be below the X+10000 mark) 125 X+10000 +------------------------+ 126 | Stack/heap | For use by the kernel real-mode code. 127 X+08000 +------------------------+ 128 | Kernel setup | The kernel real-mode code. 129 | Kernel boot sector | The kernel legacy boot sector. 130 X +------------------------+ 131 | Boot loader | <- Boot sector entry point 0000:7C00 132 001000 +------------------------+ 133 | Reserved for MBR/BIOS | 134 000800 +------------------------+ 135 | Typically used by MBR | 136 000600 +------------------------+ 137 | BIOS use only | 138 000000 +------------------------+ 139 140 ... where the address X is as low as the design of the boot loader 141 permits. 142 143 144 **** THE REAL-MODE KERNEL HEADER 145 146 In the following text, and anywhere in the kernel boot sequence, "a 147 sector" refers to 512 bytes. It is independent of the actual sector 148 size of the underlying medium. 149 150 The first step in loading a Linux kernel should be to load the 151 real-mode code (boot sector and setup code) and then examine the 152 following header at offset 0x01f1. The real-mode code can total up to 153 32K, although the boot loader may choose to load only the first two 154 sectors (1K) and then examine the bootup sector size. 155 156 The header looks like: 157 158 Offset Proto Name Meaning 159 /Size 160 161 01F1/1 ALL(1 setup_sects The size of the setup in sectors 162 01F2/2 ALL root_flags If set, the root is mounted readonly 163 01F4/4 2.04+(2 syssize The size of the 32-bit code in 16-byte paras 164 01F8/2 ALL ram_size DO NOT USE - for bootsect.S use only 165 01FA/2 ALL vid_mode Video mode control 166 01FC/2 ALL root_dev Default root device number 167 01FE/2 ALL boot_flag 0xAA55 magic number 168 0200/2 2.00+ jump Jump instruction 169 0202/4 2.00+ header Magic signature "HdrS" 170 0206/2 2.00+ version Boot protocol version supported 171 0208/4 2.00+ realmode_swtch Boot loader hook (see below) 172 020C/2 2.00+ start_sys_seg The load-low segment (0x1000) (obsolete) 173 020E/2 2.00+ kernel_version Pointer to kernel version string 174 0210/1 2.00+ type_of_loader Boot loader identifier 175 0211/1 2.00+ loadflags Boot protocol option flags 176 0212/2 2.00+ setup_move_size Move to high memory size (used with hooks) 177 0214/4 2.00+ code32_start Boot loader hook (see below) 178 0218/4 2.00+ ramdisk_image initrd load address (set by boot loader) 179 021C/4 2.00+ ramdisk_size initrd size (set by boot loader) 180 0220/4 2.00+ bootsect_kludge DO NOT USE - for bootsect.S use only 181 0224/2 2.01+ heap_end_ptr Free memory after setup end 182 0226/1 2.02+(3 ext_loader_ver Extended boot loader version 183 0227/1 2.02+(3 ext_loader_type Extended boot loader ID 184 0228/4 2.02+ cmd_line_ptr 32-bit pointer to the kernel command line 185 022C/4 2.03+ ramdisk_max Highest legal initrd address 186 0230/4 2.05+ kernel_alignment Physical addr alignment required for kernel 187 0234/1 2.05+ relocatable_kernel Whether kernel is relocatable or not 188 0235/1 2.10+ min_alignment Minimum alignment, as a power of two 189 0236/2 2.12+ xloadflags Boot protocol option flags 190 0238/4 2.06+ cmdline_size Maximum size of the kernel command line 191 023C/4 2.07+ hardware_subarch Hardware subarchitecture 192 0240/8 2.07+ hardware_subarch_data Subarchitecture-specific data 193 0248/4 2.08+ payload_offset Offset of kernel payload 194 024C/4 2.08+ payload_length Length of kernel payload 195 0250/8 2.09+ setup_data 64-bit physical pointer to linked list 196 of struct setup_data 197 0258/8 2.10+ pref_address Preferred loading address 198 0260/4 2.10+ init_size Linear memory required during initialization 199 0264/4 2.11+ handover_offset Offset of handover entry point 200 201 (1) For backwards compatibility, if the setup_sects field contains 0, the 202 real value is 4. 203 204 (2) For boot protocol prior to 2.04, the upper two bytes of the syssize 205 field are unusable, which means the size of a bzImage kernel 206 cannot be determined. 207 208 (3) Ignored, but safe to set, for boot protocols 2.02-2.09. 209 210 If the "HdrS" (0x53726448) magic number is not found at offset 0x202, 211 the boot protocol version is "old". Loading an old kernel, the 212 following parameters should be assumed: 213 214 Image type = zImage 215 initrd not supported 216 Real-mode kernel must be located at 0x90000. 217 218 Otherwise, the "version" field contains the protocol version, 219 e.g. protocol version 2.01 will contain 0x0201 in this field. When 220 setting fields in the header, you must make sure only to set fields 221 supported by the protocol version in use. 222 223 224 **** DETAILS OF HEADER FIELDS 225 226 For each field, some are information from the kernel to the bootloader 227 ("read"), some are expected to be filled out by the bootloader 228 ("write"), and some are expected to be read and modified by the 229 bootloader ("modify"). 230 231 All general purpose boot loaders should write the fields marked 232 (obligatory). Boot loaders who want to load the kernel at a 233 nonstandard address should fill in the fields marked (reloc); other 234 boot loaders can ignore those fields. 235 236 The byte order of all fields is littleendian (this is x86, after all.) 237 238 Field name: setup_sects 239 Type: read 240 Offset/size: 0x1f1/1 241 Protocol: ALL 242 243 The size of the setup code in 512-byte sectors. If this field is 244 0, the real value is 4. The real-mode code consists of the boot 245 sector (always one 512-byte sector) plus the setup code. 246 247 Field name: root_flags 248 Type: modify (optional) 249 Offset/size: 0x1f2/2 250 Protocol: ALL 251 252 If this field is nonzero, the root defaults to readonly. The use of 253 this field is deprecated; use the "ro" or "rw" options on the 254 command line instead. 255 256 Field name: syssize 257 Type: read 258 Offset/size: 0x1f4/4 (protocol 2.04+) 0x1f4/2 (protocol ALL) 259 Protocol: 2.04+ 260 261 The size of the protected-mode code in units of 16-byte paragraphs. 262 For protocol versions older than 2.04 this field is only two bytes 263 wide, and therefore cannot be trusted for the size of a kernel if 264 the LOAD_HIGH flag is set. 265 266 Field name: ram_size 267 Type: kernel internal 268 Offset/size: 0x1f8/2 269 Protocol: ALL 270 271 This field is obsolete. 272 273 Field name: vid_mode 274 Type: modify (obligatory) 275 Offset/size: 0x1fa/2 276 277 Please see the section on SPECIAL COMMAND LINE OPTIONS. 278 279 Field name: root_dev 280 Type: modify (optional) 281 Offset/size: 0x1fc/2 282 Protocol: ALL 283 284 The default root device device number. The use of this field is 285 deprecated, use the "root=" option on the command line instead. 286 287 Field name: boot_flag 288 Type: read 289 Offset/size: 0x1fe/2 290 Protocol: ALL 291 292 Contains 0xAA55. This is the closest thing old Linux kernels have 293 to a magic number. 294 295 Field name: jump 296 Type: read 297 Offset/size: 0x200/2 298 Protocol: 2.00+ 299 300 Contains an x86 jump instruction, 0xEB followed by a signed offset 301 relative to byte 0x202. This can be used to determine the size of 302 the header. 303 304 Field name: header 305 Type: read 306 Offset/size: 0x202/4 307 Protocol: 2.00+ 308 309 Contains the magic number "HdrS" (0x53726448). 310 311 Field name: version 312 Type: read 313 Offset/size: 0x206/2 314 Protocol: 2.00+ 315 316 Contains the boot protocol version, in (major << 8)+minor format, 317 e.g. 0x0204 for version 2.04, and 0x0a11 for a hypothetical version 318 10.17. 319 320 Field name: realmode_swtch 321 Type: modify (optional) 322 Offset/size: 0x208/4 323 Protocol: 2.00+ 324 325 Boot loader hook (see ADVANCED BOOT LOADER HOOKS below.) 326 327 Field name: start_sys_seg 328 Type: read 329 Offset/size: 0x20c/2 330 Protocol: 2.00+ 331 332 The load low segment (0x1000). Obsolete. 333 334 Field name: kernel_version 335 Type: read 336 Offset/size: 0x20e/2 337 Protocol: 2.00+ 338 339 If set to a nonzero value, contains a pointer to a NUL-terminated 340 human-readable kernel version number string, less 0x200. This can 341 be used to display the kernel version to the user. This value 342 should be less than (0x200*setup_sects). 343 344 For example, if this value is set to 0x1c00, the kernel version 345 number string can be found at offset 0x1e00 in the kernel file. 346 This is a valid value if and only if the "setup_sects" field 347 contains the value 15 or higher, as: 348 349 0x1c00 < 15*0x200 (= 0x1e00) but 350 0x1c00 >= 14*0x200 (= 0x1c00) 351 352 0x1c00 >> 9 = 14, so the minimum value for setup_secs is 15. 353 354 Field name: type_of_loader 355 Type: write (obligatory) 356 Offset/size: 0x210/1 357 Protocol: 2.00+ 358 359 If your boot loader has an assigned id (see table below), enter 360 0xTV here, where T is an identifier for the boot loader and V is 361 a version number. Otherwise, enter 0xFF here. 362 363 For boot loader IDs above T = 0xD, write T = 0xE to this field and 364 write the extended ID minus 0x10 to the ext_loader_type field. 365 Similarly, the ext_loader_ver field can be used to provide more than 366 four bits for the bootloader version. 367 368 For example, for T = 0x15, V = 0x234, write: 369 370 type_of_loader <- 0xE4 371 ext_loader_type <- 0x05 372 ext_loader_ver <- 0x23 373 374 Assigned boot loader ids (hexadecimal): 375 376 0 LILO (0x00 reserved for pre-2.00 bootloader) 377 1 Loadlin 378 2 bootsect-loader (0x20, all other values reserved) 379 3 Syslinux 380 4 Etherboot/gPXE/iPXE 381 5 ELILO 382 7 GRUB 383 8 U-Boot 384 9 Xen 385 A Gujin 386 B Qemu 387 C Arcturus Networks uCbootloader 388 D kexec-tools 389 E Extended (see ext_loader_type) 390 F Special (0xFF = undefined) 391 10 Reserved 392 11 Minimal Linux Bootloader <http://sebastian-plotz.blogspot.de> 393 394 Please contact <[email protected]> if you need a bootloader ID 395 value assigned. 396 397 Field name: loadflags 398 Type: modify (obligatory) 399 Offset/size: 0x211/1 400 Protocol: 2.00+ 401 402 This field is a bitmask. 403 404 Bit 0 (read): LOADED_HIGH 405 - If 0, the protected-mode code is loaded at 0x10000. 406 - If 1, the protected-mode code is loaded at 0x100000. 407 408 Bit 5 (write): QUIET_FLAG 409 - If 0, print early messages. 410 - If 1, suppress early messages. 411 This requests to the kernel (decompressor and early 412 kernel) to not write early messages that require 413 accessing the display hardware directly. 414 415 Bit 6 (write): KEEP_SEGMENTS 416 Protocol: 2.07+ 417 - If 0, reload the segment registers in the 32bit entry point. 418 - If 1, do not reload the segment registers in the 32bit entry point. 419 Assume that %cs %ds %ss %es are all set to flat segments with 420 a base of 0 (or the equivalent for their environment). 421 422 Bit 7 (write): CAN_USE_HEAP 423 Set this bit to 1 to indicate that the value entered in the 424 heap_end_ptr is valid. If this field is clear, some setup code 425 functionality will be disabled. 426 427 Field name: setup_move_size 428 Type: modify (obligatory) 429 Offset/size: 0x212/2 430 Protocol: 2.00-2.01 431 432 When using protocol 2.00 or 2.01, if the real mode kernel is not 433 loaded at 0x90000, it gets moved there later in the loading 434 sequence. Fill in this field if you want additional data (such as 435 the kernel command line) moved in addition to the real-mode kernel 436 itself. 437 438 The unit is bytes starting with the beginning of the boot sector. 439 440 This field is can be ignored when the protocol is 2.02 or higher, or 441 if the real-mode code is loaded at 0x90000. 442 443 Field name: code32_start 444 Type: modify (optional, reloc) 445 Offset/size: 0x214/4 446 Protocol: 2.00+ 447 448 The address to jump to in protected mode. This defaults to the load 449 address of the kernel, and can be used by the boot loader to 450 determine the proper load address. 451 452 This field can be modified for two purposes: 453 454 1. as a boot loader hook (see ADVANCED BOOT LOADER HOOKS below.) 455 456 2. if a bootloader which does not install a hook loads a 457 relocatable kernel at a nonstandard address it will have to modify 458 this field to point to the load address. 459 460 Field name: ramdisk_image 461 Type: write (obligatory) 462 Offset/size: 0x218/4 463 Protocol: 2.00+ 464 465 The 32-bit linear address of the initial ramdisk or ramfs. Leave at 466 zero if there is no initial ramdisk/ramfs. 467 468 Field name: ramdisk_size 469 Type: write (obligatory) 470 Offset/size: 0x21c/4 471 Protocol: 2.00+ 472 473 Size of the initial ramdisk or ramfs. Leave at zero if there is no 474 initial ramdisk/ramfs. 475 476 Field name: bootsect_kludge 477 Type: kernel internal 478 Offset/size: 0x220/4 479 Protocol: 2.00+ 480 481 This field is obsolete. 482 483 Field name: heap_end_ptr 484 Type: write (obligatory) 485 Offset/size: 0x224/2 486 Protocol: 2.01+ 487 488 Set this field to the offset (from the beginning of the real-mode 489 code) of the end of the setup stack/heap, minus 0x0200. 490 491 Field name: ext_loader_ver 492 Type: write (optional) 493 Offset/size: 0x226/1 494 Protocol: 2.02+ 495 496 This field is used as an extension of the version number in the 497 type_of_loader field. The total version number is considered to be 498 (type_of_loader & 0x0f) + (ext_loader_ver << 4). 499 500 The use of this field is boot loader specific. If not written, it 501 is zero. 502 503 Kernels prior to 2.6.31 did not recognize this field, but it is safe 504 to write for protocol version 2.02 or higher. 505 506 Field name: ext_loader_type 507 Type: write (obligatory if (type_of_loader & 0xf0) == 0xe0) 508 Offset/size: 0x227/1 509 Protocol: 2.02+ 510 511 This field is used as an extension of the type number in 512 type_of_loader field. If the type in type_of_loader is 0xE, then 513 the actual type is (ext_loader_type + 0x10). 514 515 This field is ignored if the type in type_of_loader is not 0xE. 516 517 Kernels prior to 2.6.31 did not recognize this field, but it is safe 518 to write for protocol version 2.02 or higher. 519 520 Field name: cmd_line_ptr 521 Type: write (obligatory) 522 Offset/size: 0x228/4 523 Protocol: 2.02+ 524 525 Set this field to the linear address of the kernel command line. 526 The kernel command line can be located anywhere between the end of 527 the setup heap and 0xA0000; it does not have to be located in the 528 same 64K segment as the real-mode code itself. 529 530 Fill in this field even if your boot loader does not support a 531 command line, in which case you can point this to an empty string 532 (or better yet, to the string "auto".) If this field is left at 533 zero, the kernel will assume that your boot loader does not support 534 the 2.02+ protocol. 535 536 Field name: ramdisk_max 537 Type: read 538 Offset/size: 0x22c/4 539 Protocol: 2.03+ 540 541 The maximum address that may be occupied by the initial 542 ramdisk/ramfs contents. For boot protocols 2.02 or earlier, this 543 field is not present, and the maximum address is 0x37FFFFFF. (This 544 address is defined as the address of the highest safe byte, so if 545 your ramdisk is exactly 131072 bytes long and this field is 546 0x37FFFFFF, you can start your ramdisk at 0x37FE0000.) 547 548 Field name: kernel_alignment 549 Type: read/modify (reloc) 550 Offset/size: 0x230/4 551 Protocol: 2.05+ (read), 2.10+ (modify) 552 553 Alignment unit required by the kernel (if relocatable_kernel is 554 true.) A relocatable kernel that is loaded at an alignment 555 incompatible with the value in this field will be realigned during 556 kernel initialization. 557 558 Starting with protocol version 2.10, this reflects the kernel 559 alignment preferred for optimal performance; it is possible for the 560 loader to modify this field to permit a lesser alignment. See the 561 min_alignment and pref_address field below. 562 563 Field name: relocatable_kernel 564 Type: read (reloc) 565 Offset/size: 0x234/1 566 Protocol: 2.05+ 567 568 If this field is nonzero, the protected-mode part of the kernel can 569 be loaded at any address that satisfies the kernel_alignment field. 570 After loading, the boot loader must set the code32_start field to 571 point to the loaded code, or to a boot loader hook. 572 573 Field name: min_alignment 574 Type: read (reloc) 575 Offset/size: 0x235/1 576 Protocol: 2.10+ 577 578 This field, if nonzero, indicates as a power of two the minimum 579 alignment required, as opposed to preferred, by the kernel to boot. 580 If a boot loader makes use of this field, it should update the 581 kernel_alignment field with the alignment unit desired; typically: 582 583 kernel_alignment = 1 << min_alignment 584 585 There may be a considerable performance cost with an excessively 586 misaligned kernel. Therefore, a loader should typically try each 587 power-of-two alignment from kernel_alignment down to this alignment. 588 589 Field name: xloadflags 590 Type: read 591 Offset/size: 0x236/2 592 Protocol: 2.12+ 593 594 This field is a bitmask. 595 596 Bit 0 (read): XLF_KERNEL_64 597 - If 1, this kernel has the legacy 64-bit entry point at 0x200. 598 599 Bit 1 (read): XLF_CAN_BE_LOADED_ABOVE_4G 600 - If 1, kernel/boot_params/cmdline/ramdisk can be above 4G. 601 602 Bit 2 (read): XLF_EFI_HANDOVER_32 603 - If 1, the kernel supports the 32-bit EFI handoff entry point 604 given at handover_offset. 605 606 Bit 3 (read): XLF_EFI_HANDOVER_64 607 - If 1, the kernel supports the 64-bit EFI handoff entry point 608 given at handover_offset + 0x200. 609 610 Field name: cmdline_size 611 Type: read 612 Offset/size: 0x238/4 613 Protocol: 2.06+ 614 615 The maximum size of the command line without the terminating 616 zero. This means that the command line can contain at most 617 cmdline_size characters. With protocol version 2.05 and earlier, the 618 maximum size was 255. 619 620 Field name: hardware_subarch 621 Type: write (optional, defaults to x86/PC) 622 Offset/size: 0x23c/4 623 Protocol: 2.07+ 624 625 In a paravirtualized environment the hardware low level architectural 626 pieces such as interrupt handling, page table handling, and 627 accessing process control registers needs to be done differently. 628 629 This field allows the bootloader to inform the kernel we are in one 630 one of those environments. 631 632 0x00000000 The default x86/PC environment 633 0x00000001 lguest 634 0x00000002 Xen 635 0x00000003 Moorestown MID 636 0x00000004 CE4100 TV Platform 637 638 Field name: hardware_subarch_data 639 Type: write (subarch-dependent) 640 Offset/size: 0x240/8 641 Protocol: 2.07+ 642 643 A pointer to data that is specific to hardware subarch 644 This field is currently unused for the default x86/PC environment, 645 do not modify. 646 647 Field name: payload_offset 648 Type: read 649 Offset/size: 0x248/4 650 Protocol: 2.08+ 651 652 If non-zero then this field contains the offset from the beginning 653 of the protected-mode code to the payload. 654 655 The payload may be compressed. The format of both the compressed and 656 uncompressed data should be determined using the standard magic 657 numbers. The currently supported compression formats are gzip 658 (magic numbers 1F 8B or 1F 9E), bzip2 (magic number 42 5A), LZMA 659 (magic number 5D 00), and XZ (magic number FD 37). The uncompressed 660 payload is currently always ELF (magic number 7F 45 4C 46). 661 662 Field name: payload_length 663 Type: read 664 Offset/size: 0x24c/4 665 Protocol: 2.08+ 666 667 The length of the payload. 668 669 Field name: setup_data 670 Type: write (special) 671 Offset/size: 0x250/8 672 Protocol: 2.09+ 673 674 The 64-bit physical pointer to NULL terminated single linked list of 675 struct setup_data. This is used to define a more extensible boot 676 parameters passing mechanism. The definition of struct setup_data is 677 as follow: 678 679 struct setup_data { 680 u64 next; 681 u32 type; 682 u32 len; 683 u8 data[0]; 684 }; 685 686 Where, the next is a 64-bit physical pointer to the next node of 687 linked list, the next field of the last node is 0; the type is used 688 to identify the contents of data; the len is the length of data 689 field; the data holds the real payload. 690 691 This list may be modified at a number of points during the bootup 692 process. Therefore, when modifying this list one should always make 693 sure to consider the case where the linked list already contains 694 entries. 695 696 Field name: pref_address 697 Type: read (reloc) 698 Offset/size: 0x258/8 699 Protocol: 2.10+ 700 701 This field, if nonzero, represents a preferred load address for the 702 kernel. A relocating bootloader should attempt to load at this 703 address if possible. 704 705 A non-relocatable kernel will unconditionally move itself and to run 706 at this address. 707 708 Field name: init_size 709 Type: read 710 Offset/size: 0x260/4 711 712 This field indicates the amount of linear contiguous memory starting 713 at the kernel runtime start address that the kernel needs before it 714 is capable of examining its memory map. This is not the same thing 715 as the total amount of memory the kernel needs to boot, but it can 716 be used by a relocating boot loader to help select a safe load 717 address for the kernel. 718 719 The kernel runtime start address is determined by the following algorithm: 720 721 if (relocatable_kernel) 722 runtime_start = align_up(load_address, kernel_alignment) 723 else 724 runtime_start = pref_address 725 726 Field name: handover_offset 727 Type: read 728 Offset/size: 0x264/4 729 730 This field is the offset from the beginning of the kernel image to 731 the EFI handover protocol entry point. Boot loaders using the EFI 732 handover protocol to boot the kernel should jump to this offset. 733 734 See EFI HANDOVER PROTOCOL below for more details. 735 736 737 **** THE IMAGE CHECKSUM 738 739 From boot protocol version 2.08 onwards the CRC-32 is calculated over 740 the entire file using the characteristic polynomial 0x04C11DB7 and an 741 initial remainder of 0xffffffff. The checksum is appended to the 742 file; therefore the CRC of the file up to the limit specified in the 743 syssize field of the header is always 0. 744 745 746 **** THE KERNEL COMMAND LINE 747 748 The kernel command line has become an important way for the boot 749 loader to communicate with the kernel. Some of its options are also 750 relevant to the boot loader itself, see "special command line options" 751 below. 752 753 The kernel command line is a null-terminated string. The maximum 754 length can be retrieved from the field cmdline_size. Before protocol 755 version 2.06, the maximum was 255 characters. A string that is too 756 long will be automatically truncated by the kernel. 757 758 If the boot protocol version is 2.02 or later, the address of the 759 kernel command line is given by the header field cmd_line_ptr (see 760 above.) This address can be anywhere between the end of the setup 761 heap and 0xA0000. 762 763 If the protocol version is *not* 2.02 or higher, the kernel 764 command line is entered using the following protocol: 765 766 At offset 0x0020 (word), "cmd_line_magic", enter the magic 767 number 0xA33F. 768 769 At offset 0x0022 (word), "cmd_line_offset", enter the offset 770 of the kernel command line (relative to the start of the 771 real-mode kernel). 772 773 The kernel command line *must* be within the memory region 774 covered by setup_move_size, so you may need to adjust this 775 field. 776 777 778 **** MEMORY LAYOUT OF THE REAL-MODE CODE 779 780 The real-mode code requires a stack/heap to be set up, as well as 781 memory allocated for the kernel command line. This needs to be done 782 in the real-mode accessible memory in bottom megabyte. 783 784 It should be noted that modern machines often have a sizable Extended 785 BIOS Data Area (EBDA). As a result, it is advisable to use as little 786 of the low megabyte as possible. 787 788 Unfortunately, under the following circumstances the 0x90000 memory 789 segment has to be used: 790 791 - When loading a zImage kernel ((loadflags & 0x01) == 0). 792 - When loading a 2.01 or earlier boot protocol kernel. 793 794 -> For the 2.00 and 2.01 boot protocols, the real-mode code 795 can be loaded at another address, but it is internally 796 relocated to 0x90000. For the "old" protocol, the 797 real-mode code must be loaded at 0x90000. 798 799 When loading at 0x90000, avoid using memory above 0x9a000. 800 801 For boot protocol 2.02 or higher, the command line does not have to be 802 located in the same 64K segment as the real-mode setup code; it is 803 thus permitted to give the stack/heap the full 64K segment and locate 804 the command line above it. 805 806 The kernel command line should not be located below the real-mode 807 code, nor should it be located in high memory. 808 809 810 **** SAMPLE BOOT CONFIGURATION 811 812 As a sample configuration, assume the following layout of the real 813 mode segment: 814 815 When loading below 0x90000, use the entire segment: 816 817 0x0000-0x7fff Real mode kernel 818 0x8000-0xdfff Stack and heap 819 0xe000-0xffff Kernel command line 820 821 When loading at 0x90000 OR the protocol version is 2.01 or earlier: 822 823 0x0000-0x7fff Real mode kernel 824 0x8000-0x97ff Stack and heap 825 0x9800-0x9fff Kernel command line 826 827 Such a boot loader should enter the following fields in the header: 828 829 unsigned long base_ptr; /* base address for real-mode segment */ 830 831 if ( setup_sects == 0 ) { 832 setup_sects = 4; 833 } 834 835 if ( protocol >= 0x0200 ) { 836 type_of_loader = <type code>; 837 if ( loading_initrd ) { 838 ramdisk_image = <initrd_address>; 839 ramdisk_size = <initrd_size>; 840 } 841 842 if ( protocol >= 0x0202 && loadflags & 0x01 ) 843 heap_end = 0xe000; 844 else 845 heap_end = 0x9800; 846 847 if ( protocol >= 0x0201 ) { 848 heap_end_ptr = heap_end - 0x200; 849 loadflags |= 0x80; /* CAN_USE_HEAP */ 850 } 851 852 if ( protocol >= 0x0202 ) { 853 cmd_line_ptr = base_ptr + heap_end; 854 strcpy(cmd_line_ptr, cmdline); 855 } else { 856 cmd_line_magic = 0xA33F; 857 cmd_line_offset = heap_end; 858 setup_move_size = heap_end + strlen(cmdline)+1; 859 strcpy(base_ptr+cmd_line_offset, cmdline); 860 } 861 } else { 862 /* Very old kernel */ 863 864 heap_end = 0x9800; 865 866 cmd_line_magic = 0xA33F; 867 cmd_line_offset = heap_end; 868 869 /* A very old kernel MUST have its real-mode code 870 loaded at 0x90000 */ 871 872 if ( base_ptr != 0x90000 ) { 873 /* Copy the real-mode kernel */ 874 memcpy(0x90000, base_ptr, (setup_sects+1)*512); 875 base_ptr = 0x90000; /* Relocated */ 876 } 877 878 strcpy(0x90000+cmd_line_offset, cmdline); 879 880 /* It is recommended to clear memory up to the 32K mark */ 881 memset(0x90000 + (setup_sects+1)*512, 0, 882 (64-(setup_sects+1))*512); 883 } 884 885 886 **** LOADING THE REST OF THE KERNEL 887 888 The 32-bit (non-real-mode) kernel starts at offset (setup_sects+1)*512 889 in the kernel file (again, if setup_sects == 0 the real value is 4.) 890 It should be loaded at address 0x10000 for Image/zImage kernels and 891 0x100000 for bzImage kernels. 892 893 The kernel is a bzImage kernel if the protocol >= 2.00 and the 0x01 894 bit (LOAD_HIGH) in the loadflags field is set: 895 896 is_bzImage = (protocol >= 0x0200) && (loadflags & 0x01); 897 load_address = is_bzImage ? 0x100000 : 0x10000; 898 899 Note that Image/zImage kernels can be up to 512K in size, and thus use 900 the entire 0x10000-0x90000 range of memory. This means it is pretty 901 much a requirement for these kernels to load the real-mode part at 902 0x90000. bzImage kernels allow much more flexibility. 903 904 905 **** SPECIAL COMMAND LINE OPTIONS 906 907 If the command line provided by the boot loader is entered by the 908 user, the user may expect the following command line options to work. 909 They should normally not be deleted from the kernel command line even 910 though not all of them are actually meaningful to the kernel. Boot 911 loader authors who need additional command line options for the boot 912 loader itself should get them registered in 913 Documentation/kernel-parameters.txt to make sure they will not 914 conflict with actual kernel options now or in the future. 915 916 vga=<mode> 917 <mode> here is either an integer (in C notation, either 918 decimal, octal, or hexadecimal) or one of the strings 919 "normal" (meaning 0xFFFF), "ext" (meaning 0xFFFE) or "ask" 920 (meaning 0xFFFD). This value should be entered into the 921 vid_mode field, as it is used by the kernel before the command 922 line is parsed. 923 924 mem=<size> 925 <size> is an integer in C notation optionally followed by 926 (case insensitive) K, M, G, T, P or E (meaning << 10, << 20, 927 << 30, << 40, << 50 or << 60). This specifies the end of 928 memory to the kernel. This affects the possible placement of 929 an initrd, since an initrd should be placed near end of 930 memory. Note that this is an option to *both* the kernel and 931 the bootloader! 932 933 initrd=<file> 934 An initrd should be loaded. The meaning of <file> is 935 obviously bootloader-dependent, and some boot loaders 936 (e.g. LILO) do not have such a command. 937 938 In addition, some boot loaders add the following options to the 939 user-specified command line: 940 941 BOOT_IMAGE=<file> 942 The boot image which was loaded. Again, the meaning of <file> 943 is obviously bootloader-dependent. 944 945 auto 946 The kernel was booted without explicit user intervention. 947 948 If these options are added by the boot loader, it is highly 949 recommended that they are located *first*, before the user-specified 950 or configuration-specified command line. Otherwise, "init=/bin/sh" 951 gets confused by the "auto" option. 952 953 954 **** RUNNING THE KERNEL 955 956 The kernel is started by jumping to the kernel entry point, which is 957 located at *segment* offset 0x20 from the start of the real mode 958 kernel. This means that if you loaded your real-mode kernel code at 959 0x90000, the kernel entry point is 9020:0000. 960 961 At entry, ds = es = ss should point to the start of the real-mode 962 kernel code (0x9000 if the code is loaded at 0x90000), sp should be 963 set up properly, normally pointing to the top of the heap, and 964 interrupts should be disabled. Furthermore, to guard against bugs in 965 the kernel, it is recommended that the boot loader sets fs = gs = ds = 966 es = ss. 967 968 In our example from above, we would do: 969 970 /* Note: in the case of the "old" kernel protocol, base_ptr must 971 be == 0x90000 at this point; see the previous sample code */ 972 973 seg = base_ptr >> 4; 974 975 cli(); /* Enter with interrupts disabled! */ 976 977 /* Set up the real-mode kernel stack */ 978 _SS = seg; 979 _SP = heap_end; 980 981 _DS = _ES = _FS = _GS = seg; 982 jmp_far(seg+0x20, 0); /* Run the kernel */ 983 984 If your boot sector accesses a floppy drive, it is recommended to 985 switch off the floppy motor before running the kernel, since the 986 kernel boot leaves interrupts off and thus the motor will not be 987 switched off, especially if the loaded kernel has the floppy driver as 988 a demand-loaded module! 989 990 991 **** ADVANCED BOOT LOADER HOOKS 992 993 If the boot loader runs in a particularly hostile environment (such as 994 LOADLIN, which runs under DOS) it may be impossible to follow the 995 standard memory location requirements. Such a boot loader may use the 996 following hooks that, if set, are invoked by the kernel at the 997 appropriate time. The use of these hooks should probably be 998 considered an absolutely last resort! 999 1000 IMPORTANT: All the hooks are required to preserve %esp, %ebp, %esi and 1001 %edi across invocation. 1002 1003 realmode_swtch: 1004 A 16-bit real mode far subroutine invoked immediately before 1005 entering protected mode. The default routine disables NMI, so 1006 your routine should probably do so, too. 1007 1008 code32_start: 1009 A 32-bit flat-mode routine *jumped* to immediately after the 1010 transition to protected mode, but before the kernel is 1011 uncompressed. No segments, except CS, are guaranteed to be 1012 set up (current kernels do, but older ones do not); you should 1013 set them up to BOOT_DS (0x18) yourself. 1014 1015 After completing your hook, you should jump to the address 1016 that was in this field before your boot loader overwrote it 1017 (relocated, if appropriate.) 1018 1019 1020 **** 32-bit BOOT PROTOCOL 1021 1022 For machine with some new BIOS other than legacy BIOS, such as EFI, 1023 LinuxBIOS, etc, and kexec, the 16-bit real mode setup code in kernel 1024 based on legacy BIOS can not be used, so a 32-bit boot protocol needs 1025 to be defined. 1026 1027 In 32-bit boot protocol, the first step in loading a Linux kernel 1028 should be to setup the boot parameters (struct boot_params, 1029 traditionally known as "zero page"). The memory for struct boot_params 1030 should be allocated and initialized to all zero. Then the setup header 1031 from offset 0x01f1 of kernel image on should be loaded into struct 1032 boot_params and examined. The end of setup header can be calculated as 1033 follow: 1034 1035 0x0202 + byte value at offset 0x0201 1036 1037 In addition to read/modify/write the setup header of the struct 1038 boot_params as that of 16-bit boot protocol, the boot loader should 1039 also fill the additional fields of the struct boot_params as that 1040 described in zero-page.txt. 1041 1042 After setting up the struct boot_params, the boot loader can load the 1043 32/64-bit kernel in the same way as that of 16-bit boot protocol. 1044 1045 In 32-bit boot protocol, the kernel is started by jumping to the 1046 32-bit kernel entry point, which is the start address of loaded 1047 32/64-bit kernel. 1048 1049 At entry, the CPU must be in 32-bit protected mode with paging 1050 disabled; a GDT must be loaded with the descriptors for selectors 1051 __BOOT_CS(0x10) and __BOOT_DS(0x18); both descriptors must be 4G flat 1052 segment; __BOOT_CS must have execute/read permission, and __BOOT_DS 1053 must have read/write permission; CS must be __BOOT_CS and DS, ES, SS 1054 must be __BOOT_DS; interrupt must be disabled; %esi must hold the base 1055 address of the struct boot_params; %ebp, %edi and %ebx must be zero. 1056 1057 **** EFI HANDOVER PROTOCOL 1058 1059 This protocol allows boot loaders to defer initialisation to the EFI 1060 boot stub. The boot loader is required to load the kernel/initrd(s) 1061 from the boot media and jump to the EFI handover protocol entry point 1062 which is hdr->handover_offset bytes from the beginning of 1063 startup_{32,64}. 1064 1065 The function prototype for the handover entry point looks like this, 1066 1067 efi_main(void *handle, efi_system_table_t *table, struct boot_params *bp) 1068 1069 'handle' is the EFI image handle passed to the boot loader by the EFI 1070 firmware, 'table' is the EFI system table - these are the first two 1071 arguments of the "handoff state" as described in section 2.3 of the 1072 UEFI specification. 'bp' is the boot loader-allocated boot params. 1073 1074 The boot loader *must* fill out the following fields in bp, 1075 1076 o hdr.code32_start 1077 o hdr.cmd_line_ptr 1078 o hdr.cmdline_size 1079 o hdr.ramdisk_image (if applicable) 1080 o hdr.ramdisk_size (if applicable) 1081 1082 All other fields should be zero.
  13. YUP, this is what i want ... we don't have to be dependent on Orange/xolo for updates. We can build CMs for our phone
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