uboot/tools/binman/entries.rst
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   1Binman Entry Documentation
   2===========================
   3
   4This file describes the entry types supported by binman. These entry types can
   5be placed in an image one by one to build up a final firmware image. It is
   6fairly easy to create new entry types. Just add a new file to the 'etype'
   7directory. You can use the existing entries as examples.
   8
   9Note that some entries are subclasses of others, using and extending their
  10features to produce new behaviours.
  11
  12
  13
  14Entry: atf-bl31: ARM Trusted Firmware (ATF) BL31 blob
  15-----------------------------------------------------
  16
  17Properties / Entry arguments:
  18    - atf-bl31-path: Filename of file to read into entry. This is typically
  19        called bl31.bin or bl31.elf
  20
  21This entry holds the run-time firmware, typically started by U-Boot SPL.
  22See the U-Boot README for your architecture or board for how to use it. See
  23https://github.com/ARM-software/arm-trusted-firmware for more information
  24about ATF.
  25
  26
  27
  28Entry: blob: Arbitrary binary blob
  29----------------------------------
  30
  31Note: This should not be used by itself. It is normally used as a parent
  32class by other entry types.
  33
  34Properties / Entry arguments:
  35    - filename: Filename of file to read into entry
  36    - compress: Compression algorithm to use:
  37        none: No compression
  38        lz4: Use lz4 compression (via 'lz4' command-line utility)
  39
  40This entry reads data from a file and places it in the entry. The
  41default filename is often specified specified by the subclass. See for
  42example the 'u-boot' entry which provides the filename 'u-boot.bin'.
  43
  44If compression is enabled, an extra 'uncomp-size' property is written to
  45the node (if enabled with -u) which provides the uncompressed size of the
  46data.
  47
  48
  49
  50Entry: blob-dtb: A blob that holds a device tree
  51------------------------------------------------
  52
  53This is a blob containing a device tree. The contents of the blob are
  54obtained from the list of available device-tree files, managed by the
  55'state' module.
  56
  57
  58
  59Entry: blob-ext: Externally built binary blob
  60---------------------------------------------
  61
  62Note: This should not be used by itself. It is normally used as a parent
  63class by other entry types.
  64
  65If the file providing this blob is missing, binman can optionally ignore it
  66and produce a broken image with a warning.
  67
  68See 'blob' for Properties / Entry arguments.
  69
  70
  71
  72Entry: blob-named-by-arg: A blob entry which gets its filename property from its subclass
  73-----------------------------------------------------------------------------------------
  74
  75Properties / Entry arguments:
  76    - <xxx>-path: Filename containing the contents of this entry (optional,
  77        defaults to None)
  78
  79where <xxx> is the blob_fname argument to the constructor.
  80
  81This entry cannot be used directly. Instead, it is used as a parent class
  82for another entry, which defined blob_fname. This parameter is used to
  83set the entry-arg or property containing the filename. The entry-arg or
  84property is in turn used to set the actual filename.
  85
  86See cros_ec_rw for an example of this.
  87
  88
  89
  90Entry: blob-phase: Section that holds a phase binary
  91----------------------------------------------------
  92
  93This is a base class that should not normally be used directly. It is used
  94when converting a 'u-boot' entry automatically into a 'u-boot-expanded'
  95entry; similarly for SPL.
  96
  97
  98
  99Entry: cbfs: Coreboot Filesystem (CBFS)
 100---------------------------------------
 101
 102A CBFS provides a way to group files into a group. It has a simple directory
 103structure and allows the position of individual files to be set, since it is
 104designed to support execute-in-place in an x86 SPI-flash device. Where XIP
 105is not used, it supports compression and storing ELF files.
 106
 107CBFS is used by coreboot as its way of orgnanising SPI-flash contents.
 108
 109The contents of the CBFS are defined by subnodes of the cbfs entry, e.g.::
 110
 111    cbfs {
 112        size = <0x100000>;
 113        u-boot {
 114            cbfs-type = "raw";
 115        };
 116        u-boot-dtb {
 117            cbfs-type = "raw";
 118        };
 119    };
 120
 121This creates a CBFS 1MB in size two files in it: u-boot.bin and u-boot.dtb.
 122Note that the size is required since binman does not support calculating it.
 123The contents of each entry is just what binman would normally provide if it
 124were not a CBFS node. A blob type can be used to import arbitrary files as
 125with the second subnode below::
 126
 127    cbfs {
 128        size = <0x100000>;
 129        u-boot {
 130            cbfs-name = "BOOT";
 131            cbfs-type = "raw";
 132        };
 133
 134        dtb {
 135            type = "blob";
 136            filename = "u-boot.dtb";
 137            cbfs-type = "raw";
 138            cbfs-compress = "lz4";
 139            cbfs-offset = <0x100000>;
 140        };
 141    };
 142
 143This creates a CBFS 1MB in size with u-boot.bin (named "BOOT") and
 144u-boot.dtb (named "dtb") and compressed with the lz4 algorithm.
 145
 146
 147Properties supported in the top-level CBFS node:
 148
 149cbfs-arch:
 150    Defaults to "x86", but you can specify the architecture if needed.
 151
 152
 153Properties supported in the CBFS entry subnodes:
 154
 155cbfs-name:
 156    This is the name of the file created in CBFS. It defaults to the entry
 157    name (which is the node name), but you can override it with this
 158    property.
 159
 160cbfs-type:
 161    This is the CBFS file type. The following are supported:
 162
 163    raw:
 164        This is a 'raw' file, although compression is supported. It can be
 165        used to store any file in CBFS.
 166
 167    stage:
 168        This is an ELF file that has been loaded (i.e. mapped to memory), so
 169        appears in the CBFS as a flat binary. The input file must be an ELF
 170        image, for example this puts "u-boot" (the ELF image) into a 'stage'
 171        entry::
 172
 173            cbfs {
 174                size = <0x100000>;
 175                u-boot-elf {
 176                    cbfs-name = "BOOT";
 177                    cbfs-type = "stage";
 178                };
 179            };
 180
 181        You can use your own ELF file with something like::
 182
 183            cbfs {
 184                size = <0x100000>;
 185                something {
 186                    type = "blob";
 187                    filename = "cbfs-stage.elf";
 188                    cbfs-type = "stage";
 189                };
 190            };
 191
 192        As mentioned, the file is converted to a flat binary, so it is
 193        equivalent to adding "u-boot.bin", for example, but with the load and
 194        start addresses specified by the ELF. At present there is no option
 195        to add a flat binary with a load/start address, similar to the
 196        'add-flat-binary' option in cbfstool.
 197
 198cbfs-offset:
 199    This is the offset of the file's data within the CBFS. It is used to
 200    specify where the file should be placed in cases where a fixed position
 201    is needed. Typical uses are for code which is not relocatable and must
 202    execute in-place from a particular address. This works because SPI flash
 203    is generally mapped into memory on x86 devices. The file header is
 204    placed before this offset so that the data start lines up exactly with
 205    the chosen offset. If this property is not provided, then the file is
 206    placed in the next available spot.
 207
 208The current implementation supports only a subset of CBFS features. It does
 209not support other file types (e.g. payload), adding multiple files (like the
 210'files' entry with a pattern supported by binman), putting files at a
 211particular offset in the CBFS and a few other things.
 212
 213Of course binman can create images containing multiple CBFSs, simply by
 214defining these in the binman config::
 215
 216
 217    binman {
 218        size = <0x800000>;
 219        cbfs {
 220            offset = <0x100000>;
 221            size = <0x100000>;
 222            u-boot {
 223                cbfs-type = "raw";
 224            };
 225            u-boot-dtb {
 226                cbfs-type = "raw";
 227            };
 228        };
 229
 230        cbfs2 {
 231            offset = <0x700000>;
 232            size = <0x100000>;
 233            u-boot {
 234                cbfs-type = "raw";
 235            };
 236            u-boot-dtb {
 237                cbfs-type = "raw";
 238            };
 239            image {
 240                type = "blob";
 241                filename = "image.jpg";
 242            };
 243        };
 244    };
 245
 246This creates an 8MB image with two CBFSs, one at offset 1MB, one at 7MB,
 247both of size 1MB.
 248
 249
 250
 251Entry: collection: An entry which contains a collection of other entries
 252------------------------------------------------------------------------
 253
 254Properties / Entry arguments:
 255    - content: List of phandles to entries to include
 256
 257This allows reusing the contents of other entries. The contents of the
 258listed entries are combined to form this entry. This serves as a useful
 259base class for entry types which need to process data from elsewhere in
 260the image, not necessarily child entries.
 261
 262
 263
 264Entry: cros-ec-rw: A blob entry which contains a Chromium OS read-write EC image
 265--------------------------------------------------------------------------------
 266
 267Properties / Entry arguments:
 268    - cros-ec-rw-path: Filename containing the EC image
 269
 270This entry holds a Chromium OS EC (embedded controller) image, for use in
 271updating the EC on startup via software sync.
 272
 273
 274
 275Entry: fdtmap: An entry which contains an FDT map
 276-------------------------------------------------
 277
 278Properties / Entry arguments:
 279    None
 280
 281An FDT map is just a header followed by an FDT containing a list of all the
 282entries in the image. The root node corresponds to the image node in the
 283original FDT, and an image-name property indicates the image name in that
 284original tree.
 285
 286The header is the string _FDTMAP_ followed by 8 unused bytes.
 287
 288When used, this entry will be populated with an FDT map which reflects the
 289entries in the current image. Hierarchy is preserved, and all offsets and
 290sizes are included.
 291
 292Note that the -u option must be provided to ensure that binman updates the
 293FDT with the position of each entry.
 294
 295Example output for a simple image with U-Boot and an FDT map::
 296
 297    / {
 298        image-name = "binman";
 299        size = <0x00000112>;
 300        image-pos = <0x00000000>;
 301        offset = <0x00000000>;
 302        u-boot {
 303            size = <0x00000004>;
 304            image-pos = <0x00000000>;
 305            offset = <0x00000000>;
 306        };
 307        fdtmap {
 308            size = <0x0000010e>;
 309            image-pos = <0x00000004>;
 310            offset = <0x00000004>;
 311        };
 312    };
 313
 314If allow-repack is used then 'orig-offset' and 'orig-size' properties are
 315added as necessary. See the binman README.
 316
 317
 318
 319Entry: files: A set of files arranged in a section
 320--------------------------------------------------
 321
 322Properties / Entry arguments:
 323    - pattern: Filename pattern to match the files to include
 324    - files-compress: Compression algorithm to use:
 325        none: No compression
 326        lz4: Use lz4 compression (via 'lz4' command-line utility)
 327    - files-align: Align each file to the given alignment
 328
 329This entry reads a number of files and places each in a separate sub-entry
 330within this entry. To access these you need to enable device-tree updates
 331at run-time so you can obtain the file positions.
 332
 333
 334
 335Entry: fill: An entry which is filled to a particular byte value
 336----------------------------------------------------------------
 337
 338Properties / Entry arguments:
 339    - fill-byte: Byte to use to fill the entry
 340
 341Note that the size property must be set since otherwise this entry does not
 342know how large it should be.
 343
 344You can often achieve the same effect using the pad-byte property of the
 345overall image, in that the space between entries will then be padded with
 346that byte. But this entry is sometimes useful for explicitly setting the
 347byte value of a region.
 348
 349
 350
 351Entry: fit: Flat Image Tree (FIT)
 352---------------------------------
 353
 354This calls mkimage to create a FIT (U-Boot Flat Image Tree) based on the
 355input provided.
 356
 357Nodes for the FIT should be written out in the binman configuration just as
 358they would be in a file passed to mkimage.
 359
 360For example, this creates an image containing a FIT with U-Boot SPL::
 361
 362    binman {
 363        fit {
 364            description = "Test FIT";
 365            fit,fdt-list = "of-list";
 366
 367            images {
 368                kernel@1 {
 369                    description = "SPL";
 370                    os = "u-boot";
 371                    type = "rkspi";
 372                    arch = "arm";
 373                    compression = "none";
 374                    load = <0>;
 375                    entry = <0>;
 376
 377                    u-boot-spl {
 378                    };
 379                };
 380            };
 381        };
 382    };
 383
 384U-Boot supports creating fdt and config nodes automatically. To do this,
 385pass an of-list property (e.g. -a of-list=file1 file2). This tells binman
 386that you want to generates nodes for two files: file1.dtb and file2.dtb
 387The fit,fdt-list property (see above) indicates that of-list should be used.
 388If the property is missing you will get an error.
 389
 390Then add a 'generator node', a node with a name starting with '@'::
 391
 392    images {
 393        @fdt-SEQ {
 394            description = "fdt-NAME";
 395            type = "flat_dt";
 396            compression = "none";
 397        };
 398    };
 399
 400This tells binman to create nodes fdt-1 and fdt-2 for each of your two
 401files. All the properties you specify will be included in the node. This
 402node acts like a template to generate the nodes. The generator node itself
 403does not appear in the output - it is replaced with what binman generates.
 404
 405You can create config nodes in a similar way::
 406
 407    configurations {
 408        default = "@config-DEFAULT-SEQ";
 409        @config-SEQ {
 410            description = "NAME";
 411            firmware = "atf";
 412            loadables = "uboot";
 413            fdt = "fdt-SEQ";
 414        };
 415    };
 416
 417This tells binman to create nodes config-1 and config-2, i.e. a config for
 418each of your two files.
 419
 420Available substitutions for '@' nodes are:
 421
 422SEQ:
 423    Sequence number of the generated fdt (1, 2, ...)
 424NAME
 425    Name of the dtb as provided (i.e. without adding '.dtb')
 426
 427Note that if no devicetree files are provided (with '-a of-list' as above)
 428then no nodes will be generated.
 429
 430The 'default' property, if present, will be automatically set to the name
 431if of configuration whose devicetree matches the 'default-dt' entry
 432argument, e.g. with '-a default-dt=sun50i-a64-pine64-lts'.
 433
 434Available substitutions for '@' property values are
 435
 436DEFAULT-SEQ:
 437    Sequence number of the default fdt,as provided by the 'default-dt' entry
 438    argument
 439
 440Properties (in the 'fit' node itself):
 441    fit,external-offset: Indicates that the contents of the FIT are external
 442        and provides the external offset. This is passsed to mkimage via
 443        the -E and -p flags.
 444
 445
 446
 447
 448Entry: fmap: An entry which contains an Fmap section
 449----------------------------------------------------
 450
 451Properties / Entry arguments:
 452    None
 453
 454FMAP is a simple format used by flashrom, an open-source utility for
 455reading and writing the SPI flash, typically on x86 CPUs. The format
 456provides flashrom with a list of areas, so it knows what it in the flash.
 457It can then read or write just a single area, instead of the whole flash.
 458
 459The format is defined by the flashrom project, in the file lib/fmap.h -
 460see www.flashrom.org/Flashrom for more information.
 461
 462When used, this entry will be populated with an FMAP which reflects the
 463entries in the current image. Note that any hierarchy is squashed, since
 464FMAP does not support this. Sections are represented as an area appearing
 465before its contents, so that it is possible to reconstruct the hierarchy
 466from the FMAP by using the offset information. This convention does not
 467seem to be documented, but is used in Chromium OS.
 468
 469CBFS entries appear as a single entry, i.e. the sub-entries are ignored.
 470
 471
 472
 473Entry: gbb: An entry which contains a Chromium OS Google Binary Block
 474---------------------------------------------------------------------
 475
 476Properties / Entry arguments:
 477    - hardware-id: Hardware ID to use for this build (a string)
 478    - keydir: Directory containing the public keys to use
 479    - bmpblk: Filename containing images used by recovery
 480
 481Chromium OS uses a GBB to store various pieces of information, in particular
 482the root and recovery keys that are used to verify the boot process. Some
 483more details are here:
 484
 485    https://www.chromium.org/chromium-os/firmware-porting-guide/2-concepts
 486
 487but note that the page dates from 2013 so is quite out of date. See
 488README.chromium for how to obtain the required keys and tools.
 489
 490
 491
 492Entry: image-header: An entry which contains a pointer to the FDT map
 493---------------------------------------------------------------------
 494
 495Properties / Entry arguments:
 496    location: Location of header ("start" or "end" of image). This is
 497        optional. If omitted then the entry must have an offset property.
 498
 499This adds an 8-byte entry to the start or end of the image, pointing to the
 500location of the FDT map. The format is a magic number followed by an offset
 501from the start or end of the image, in twos-compliment format.
 502
 503This entry must be in the top-level part of the image.
 504
 505NOTE: If the location is at the start/end, you will probably need to specify
 506sort-by-offset for the image, unless you actually put the image header
 507first/last in the entry list.
 508
 509
 510
 511Entry: intel-cmc: Intel Chipset Micro Code (CMC) file
 512-----------------------------------------------------
 513
 514Properties / Entry arguments:
 515    - filename: Filename of file to read into entry
 516
 517This file contains microcode for some devices in a special format. An
 518example filename is 'Microcode/C0_22211.BIN'.
 519
 520See README.x86 for information about x86 binary blobs.
 521
 522
 523
 524Entry: intel-descriptor: Intel flash descriptor block (4KB)
 525-----------------------------------------------------------
 526
 527Properties / Entry arguments:
 528    filename: Filename of file containing the descriptor. This is typically
 529        a 4KB binary file, sometimes called 'descriptor.bin'
 530
 531This entry is placed at the start of flash and provides information about
 532the SPI flash regions. In particular it provides the base address and
 533size of the ME (Management Engine) region, allowing us to place the ME
 534binary in the right place.
 535
 536With this entry in your image, the position of the 'intel-me' entry will be
 537fixed in the image, which avoids you needed to specify an offset for that
 538region. This is useful, because it is not possible to change the position
 539of the ME region without updating the descriptor.
 540
 541See README.x86 for information about x86 binary blobs.
 542
 543
 544
 545Entry: intel-fit: Intel Firmware Image Table (FIT)
 546--------------------------------------------------
 547
 548This entry contains a dummy FIT as required by recent Intel CPUs. The FIT
 549contains information about the firmware and microcode available in the
 550image.
 551
 552At present binman only supports a basic FIT with no microcode.
 553
 554
 555
 556Entry: intel-fit-ptr: Intel Firmware Image Table (FIT) pointer
 557--------------------------------------------------------------
 558
 559This entry contains a pointer to the FIT. It is required to be at address
 5600xffffffc0 in the image.
 561
 562
 563
 564Entry: intel-fsp: Intel Firmware Support Package (FSP) file
 565-----------------------------------------------------------
 566
 567Properties / Entry arguments:
 568    - filename: Filename of file to read into entry
 569
 570This file contains binary blobs which are used on some devices to make the
 571platform work. U-Boot executes this code since it is not possible to set up
 572the hardware using U-Boot open-source code. Documentation is typically not
 573available in sufficient detail to allow this.
 574
 575An example filename is 'FSP/QUEENSBAY_FSP_GOLD_001_20-DECEMBER-2013.fd'
 576
 577See README.x86 for information about x86 binary blobs.
 578
 579
 580
 581Entry: intel-fsp-m: Intel Firmware Support Package (FSP) memory init
 582--------------------------------------------------------------------
 583
 584Properties / Entry arguments:
 585    - filename: Filename of file to read into entry
 586
 587This file contains a binary blob which is used on some devices to set up
 588SDRAM. U-Boot executes this code in SPL so that it can make full use of
 589memory. Documentation is typically not available in sufficient detail to
 590allow U-Boot do this this itself..
 591
 592An example filename is 'fsp_m.bin'
 593
 594See README.x86 for information about x86 binary blobs.
 595
 596
 597
 598Entry: intel-fsp-s: Intel Firmware Support Package (FSP) silicon init
 599---------------------------------------------------------------------
 600
 601Properties / Entry arguments:
 602    - filename: Filename of file to read into entry
 603
 604This file contains a binary blob which is used on some devices to set up
 605the silicon. U-Boot executes this code in U-Boot proper after SDRAM is
 606running, so that it can make full use of memory. Documentation is typically
 607not available in sufficient detail to allow U-Boot do this this itself.
 608
 609An example filename is 'fsp_s.bin'
 610
 611See README.x86 for information about x86 binary blobs.
 612
 613
 614
 615Entry: intel-fsp-t: Intel Firmware Support Package (FSP) temp ram init
 616----------------------------------------------------------------------
 617
 618Properties / Entry arguments:
 619    - filename: Filename of file to read into entry
 620
 621This file contains a binary blob which is used on some devices to set up
 622temporary memory (Cache-as-RAM or CAR). U-Boot executes this code in TPL so
 623that it has access to memory for its stack and initial storage.
 624
 625An example filename is 'fsp_t.bin'
 626
 627See README.x86 for information about x86 binary blobs.
 628
 629
 630
 631Entry: intel-ifwi: Intel Integrated Firmware Image (IFWI) file
 632--------------------------------------------------------------
 633
 634Properties / Entry arguments:
 635    - filename: Filename of file to read into entry. This is either the
 636        IFWI file itself, or a file that can be converted into one using a
 637        tool
 638    - convert-fit: If present this indicates that the ifwitool should be
 639        used to convert the provided file into a IFWI.
 640
 641This file contains code and data used by the SoC that is required to make
 642it work. It includes U-Boot TPL, microcode, things related to the CSE
 643(Converged Security Engine, the microcontroller that loads all the firmware)
 644and other items beyond the wit of man.
 645
 646A typical filename is 'ifwi.bin' for an IFWI file, or 'fitimage.bin' for a
 647file that will be converted to an IFWI.
 648
 649The position of this entry is generally set by the intel-descriptor entry.
 650
 651The contents of the IFWI are specified by the subnodes of the IFWI node.
 652Each subnode describes an entry which is placed into the IFWFI with a given
 653sub-partition (and optional entry name).
 654
 655Properties for subnodes:
 656    - ifwi-subpart: sub-parition to put this entry into, e.g. "IBBP"
 657    - ifwi-entry: entry name t use, e.g. "IBBL"
 658    - ifwi-replace: if present, indicates that the item should be replaced
 659      in the IFWI. Otherwise it is added.
 660
 661See README.x86 for information about x86 binary blobs.
 662
 663
 664
 665Entry: intel-me: Intel Management Engine (ME) file
 666--------------------------------------------------
 667
 668Properties / Entry arguments:
 669    - filename: Filename of file to read into entry
 670
 671This file contains code used by the SoC that is required to make it work.
 672The Management Engine is like a background task that runs things that are
 673not clearly documented, but may include keyboard, display and network
 674access. For platform that use ME it is not possible to disable it. U-Boot
 675does not directly execute code in the ME binary.
 676
 677A typical filename is 'me.bin'.
 678
 679The position of this entry is generally set by the intel-descriptor entry.
 680
 681See README.x86 for information about x86 binary blobs.
 682
 683
 684
 685Entry: intel-mrc: Intel Memory Reference Code (MRC) file
 686--------------------------------------------------------
 687
 688Properties / Entry arguments:
 689    - filename: Filename of file to read into entry
 690
 691This file contains code for setting up the SDRAM on some Intel systems. This
 692is executed by U-Boot when needed early during startup. A typical filename
 693is 'mrc.bin'.
 694
 695See README.x86 for information about x86 binary blobs.
 696
 697
 698
 699Entry: intel-refcode: Intel Reference Code file
 700-----------------------------------------------
 701
 702Properties / Entry arguments:
 703    - filename: Filename of file to read into entry
 704
 705This file contains code for setting up the platform on some Intel systems.
 706This is executed by U-Boot when needed early during startup. A typical
 707filename is 'refcode.bin'.
 708
 709See README.x86 for information about x86 binary blobs.
 710
 711
 712
 713Entry: intel-vbt: Intel Video BIOS Table (VBT) file
 714---------------------------------------------------
 715
 716Properties / Entry arguments:
 717    - filename: Filename of file to read into entry
 718
 719This file contains code that sets up the integrated graphics subsystem on
 720some Intel SoCs. U-Boot executes this when the display is started up.
 721
 722See README.x86 for information about Intel binary blobs.
 723
 724
 725
 726Entry: intel-vga: Intel Video Graphics Adaptor (VGA) file
 727---------------------------------------------------------
 728
 729Properties / Entry arguments:
 730    - filename: Filename of file to read into entry
 731
 732This file contains code that sets up the integrated graphics subsystem on
 733some Intel SoCs. U-Boot executes this when the display is started up.
 734
 735This is similar to the VBT file but in a different format.
 736
 737See README.x86 for information about Intel binary blobs.
 738
 739
 740
 741Entry: mkimage: Binary produced by mkimage
 742------------------------------------------
 743
 744Properties / Entry arguments:
 745    - datafile: Filename for -d argument
 746    - args: Other arguments to pass
 747
 748The data passed to mkimage is collected from subnodes of the mkimage node,
 749e.g.::
 750
 751    mkimage {
 752        args = "-n test -T imximage";
 753
 754        u-boot-spl {
 755        };
 756    };
 757
 758This calls mkimage to create an imximage with u-boot-spl.bin as the input
 759file. The output from mkimage then becomes part of the image produced by
 760binman.
 761
 762
 763
 764Entry: opensbi: RISC-V OpenSBI fw_dynamic blob
 765----------------------------------------------
 766
 767Properties / Entry arguments:
 768    - opensbi-path: Filename of file to read into entry. This is typically
 769        called fw_dynamic.bin
 770
 771This entry holds the run-time firmware, typically started by U-Boot SPL.
 772See the U-Boot README for your architecture or board for how to use it. See
 773https://github.com/riscv/opensbi for more information about OpenSBI.
 774
 775
 776
 777Entry: powerpc-mpc85xx-bootpg-resetvec: PowerPC mpc85xx bootpg + resetvec code for U-Boot
 778-----------------------------------------------------------------------------------------
 779
 780Properties / Entry arguments:
 781    - filename: Filename of u-boot-br.bin (default 'u-boot-br.bin')
 782
 783This entry is valid for PowerPC mpc85xx cpus. This entry holds
 784'bootpg + resetvec' code for PowerPC mpc85xx CPUs which needs to be
 785placed at offset 'RESET_VECTOR_ADDRESS - 0xffc'.
 786
 787
 788
 789Entry: scp: System Control Processor (SCP) firmware blob
 790--------------------------------------------------------
 791
 792Properties / Entry arguments:
 793    - scp-path: Filename of file to read into the entry, typically scp.bin
 794
 795This entry holds firmware for an external platform-specific coprocessor.
 796
 797
 798
 799Entry: section: Entry that contains other entries
 800-------------------------------------------------
 801
 802Properties / Entry arguments: (see binman README for more information):
 803    pad-byte: Pad byte to use when padding
 804    sort-by-offset: True if entries should be sorted by offset, False if
 805    they must be in-order in the device tree description
 806
 807    end-at-4gb: Used to build an x86 ROM which ends at 4GB (2^32)
 808
 809    skip-at-start: Number of bytes before the first entry starts. These
 810        effectively adjust the starting offset of entries. For example,
 811        if this is 16, then the first entry would start at 16. An entry
 812        with offset = 20 would in fact be written at offset 4 in the image
 813        file, since the first 16 bytes are skipped when writing.
 814    name-prefix: Adds a prefix to the name of every entry in the section
 815        when writing out the map
 816    align_default: Default alignment for this section, if no alignment is
 817        given in the entry
 818
 819Properties:
 820    allow_missing: True if this section permits external blobs to be
 821        missing their contents. The second will produce an image but of
 822        course it will not work.
 823
 824Properties:
 825    _allow_missing: True if this section permits external blobs to be
 826        missing their contents. The second will produce an image but of
 827        course it will not work.
 828
 829Since a section is also an entry, it inherits all the properies of entries
 830too.
 831
 832A section is an entry which can contain other entries, thus allowing
 833hierarchical images to be created. See 'Sections and hierarchical images'
 834in the binman README for more information.
 835
 836
 837
 838Entry: text: An entry which contains text
 839-----------------------------------------
 840
 841The text can be provided either in the node itself or by a command-line
 842argument. There is a level of indirection to allow multiple text strings
 843and sharing of text.
 844
 845Properties / Entry arguments:
 846    text-label: The value of this string indicates the property / entry-arg
 847        that contains the string to place in the entry
 848    <xxx> (actual name is the value of text-label): contains the string to
 849        place in the entry.
 850    <text>: The text to place in the entry (overrides the above mechanism).
 851        This is useful when the text is constant.
 852
 853Example node::
 854
 855    text {
 856        size = <50>;
 857        text-label = "message";
 858    };
 859
 860You can then use:
 861
 862    binman -amessage="this is my message"
 863
 864and binman will insert that string into the entry.
 865
 866It is also possible to put the string directly in the node::
 867
 868    text {
 869        size = <8>;
 870        text-label = "message";
 871        message = "a message directly in the node"
 872    };
 873
 874or just::
 875
 876    text {
 877        size = <8>;
 878        text = "some text directly in the node"
 879    };
 880
 881The text is not itself nul-terminated. This can be achieved, if required,
 882by setting the size of the entry to something larger than the text.
 883
 884
 885
 886Entry: u-boot: U-Boot flat binary
 887---------------------------------
 888
 889Properties / Entry arguments:
 890    - filename: Filename of u-boot.bin (default 'u-boot.bin')
 891
 892This is the U-Boot binary, containing relocation information to allow it
 893to relocate itself at runtime. The binary typically includes a device tree
 894blob at the end of it.
 895
 896U-Boot can access binman symbols at runtime. See:
 897
 898    'Access to binman entry offsets at run time (fdt)'
 899
 900in the binman README for more information.
 901
 902Note that this entry is automatically replaced with u-boot-expanded unless
 903--no-expanded is used or the node has a 'no-expanded' property.
 904
 905
 906
 907Entry: u-boot-dtb: U-Boot device tree
 908-------------------------------------
 909
 910Properties / Entry arguments:
 911    - filename: Filename of u-boot.dtb (default 'u-boot.dtb')
 912
 913This is the U-Boot device tree, containing configuration information for
 914U-Boot. U-Boot needs this to know what devices are present and which drivers
 915to activate.
 916
 917Note: This is mostly an internal entry type, used by others. This allows
 918binman to know which entries contain a device tree.
 919
 920
 921
 922Entry: u-boot-dtb-with-ucode: A U-Boot device tree file, with the microcode removed
 923-----------------------------------------------------------------------------------
 924
 925Properties / Entry arguments:
 926    - filename: Filename of u-boot.dtb (default 'u-boot.dtb')
 927
 928See Entry_u_boot_ucode for full details of the three entries involved in
 929this process. This entry provides the U-Boot device-tree file, which
 930contains the microcode. If the microcode is not being collated into one
 931place then the offset and size of the microcode is recorded by this entry,
 932for use by u-boot-with-ucode_ptr. If it is being collated, then this
 933entry deletes the microcode from the device tree (to save space) and makes
 934it available to u-boot-ucode.
 935
 936
 937
 938Entry: u-boot-elf: U-Boot ELF image
 939-----------------------------------
 940
 941Properties / Entry arguments:
 942    - filename: Filename of u-boot (default 'u-boot')
 943
 944This is the U-Boot ELF image. It does not include a device tree but can be
 945relocated to any address for execution.
 946
 947
 948
 949Entry: u-boot-env: An entry which contains a U-Boot environment
 950---------------------------------------------------------------
 951
 952Properties / Entry arguments:
 953    - filename: File containing the environment text, with each line in the
 954        form var=value
 955
 956
 957
 958Entry: u-boot-expanded: U-Boot flat binary broken out into its component parts
 959------------------------------------------------------------------------------
 960
 961This is a section containing the U-Boot binary and a devicetree. Using this
 962entry type automatically creates this section, with the following entries
 963in it:
 964
 965   u-boot-nodtb
 966   u-boot-dtb
 967
 968Having the devicetree separate allows binman to update it in the final
 969image, so that the entries positions are provided to the running U-Boot.
 970
 971
 972
 973Entry: u-boot-img: U-Boot legacy image
 974--------------------------------------
 975
 976Properties / Entry arguments:
 977    - filename: Filename of u-boot.img (default 'u-boot.img')
 978
 979This is the U-Boot binary as a packaged image, in legacy format. It has a
 980header which allows it to be loaded at the correct address for execution.
 981
 982You should use FIT (Flat Image Tree) instead of the legacy image for new
 983applications.
 984
 985
 986
 987Entry: u-boot-nodtb: U-Boot flat binary without device tree appended
 988--------------------------------------------------------------------
 989
 990Properties / Entry arguments:
 991    - filename: Filename to include (default 'u-boot-nodtb.bin')
 992
 993This is the U-Boot binary, containing relocation information to allow it
 994to relocate itself at runtime. It does not include a device tree blob at
 995the end of it so normally cannot work without it. You can add a u-boot-dtb
 996entry after this one, or use a u-boot entry instead, normally expands to a
 997section containing u-boot and u-boot-dtb
 998
 999
1000
1001Entry: u-boot-spl: U-Boot SPL binary
1002------------------------------------
1003
1004Properties / Entry arguments:
1005    - filename: Filename of u-boot-spl.bin (default 'spl/u-boot-spl.bin')
1006
1007This is the U-Boot SPL (Secondary Program Loader) binary. This is a small
1008binary which loads before U-Boot proper, typically into on-chip SRAM. It is
1009responsible for locating, loading and jumping to U-Boot. Note that SPL is
1010not relocatable so must be loaded to the correct address in SRAM, or written
1011to run from the correct address if direct flash execution is possible (e.g.
1012on x86 devices).
1013
1014SPL can access binman symbols at runtime. See:
1015
1016    'Access to binman entry offsets at run time (symbols)'
1017
1018in the binman README for more information.
1019
1020The ELF file 'spl/u-boot-spl' must also be available for this to work, since
1021binman uses that to look up symbols to write into the SPL binary.
1022
1023Note that this entry is automatically replaced with u-boot-spl-expanded
1024unless --no-expanded is used or the node has a 'no-expanded' property.
1025
1026
1027
1028Entry: u-boot-spl-bss-pad: U-Boot SPL binary padded with a BSS region
1029---------------------------------------------------------------------
1030
1031Properties / Entry arguments:
1032    None
1033
1034This holds the padding added after the SPL binary to cover the BSS (Block
1035Started by Symbol) region. This region holds the various variables used by
1036SPL. It is set to 0 by SPL when it starts up. If you want to append data to
1037the SPL image (such as a device tree file), you must pad out the BSS region
1038to avoid the data overlapping with U-Boot variables. This entry is useful in
1039that case. It automatically pads out the entry size to cover both the code,
1040data and BSS.
1041
1042The contents of this entry will a certain number of zero bytes, determined
1043by __bss_size
1044
1045The ELF file 'spl/u-boot-spl' must also be available for this to work, since
1046binman uses that to look up the BSS address.
1047
1048
1049
1050Entry: u-boot-spl-dtb: U-Boot SPL device tree
1051---------------------------------------------
1052
1053Properties / Entry arguments:
1054    - filename: Filename of u-boot.dtb (default 'spl/u-boot-spl.dtb')
1055
1056This is the SPL device tree, containing configuration information for
1057SPL. SPL needs this to know what devices are present and which drivers
1058to activate.
1059
1060
1061
1062Entry: u-boot-spl-elf: U-Boot SPL ELF image
1063-------------------------------------------
1064
1065Properties / Entry arguments:
1066    - filename: Filename of SPL u-boot (default 'spl/u-boot-spl')
1067
1068This is the U-Boot SPL ELF image. It does not include a device tree but can
1069be relocated to any address for execution.
1070
1071
1072
1073Entry: u-boot-spl-expanded: U-Boot SPL flat binary broken out into its component parts
1074--------------------------------------------------------------------------------------
1075
1076Properties / Entry arguments:
1077    - spl-dtb: Controls whether this entry is selected (set to 'y' or '1' to
1078        select)
1079
1080This is a section containing the U-Boot binary, BSS padding if needed and a
1081devicetree. Using this entry type automatically creates this section, with
1082the following entries in it:
1083
1084   u-boot-spl-nodtb
1085   u-boot-spl-bss-pad
1086   u-boot-dtb
1087
1088Having the devicetree separate allows binman to update it in the final
1089image, so that the entries positions are provided to the running U-Boot.
1090
1091This entry is selected based on the value of the 'spl-dtb' entryarg. If
1092this is non-empty (and not 'n' or '0') then this expanded entry is selected.
1093
1094
1095
1096Entry: u-boot-spl-nodtb: SPL binary without device tree appended
1097----------------------------------------------------------------
1098
1099Properties / Entry arguments:
1100    - filename: Filename to include (default 'spl/u-boot-spl-nodtb.bin')
1101
1102This is the U-Boot SPL binary, It does not include a device tree blob at
1103the end of it so may not be able to work without it, assuming SPL needs
1104a device tree to operate on your platform. You can add a u-boot-spl-dtb
1105entry after this one, or use a u-boot-spl entry instead' which normally
1106expands to a section containing u-boot-spl-dtb, u-boot-spl-bss-pad and
1107u-boot-spl-dtb
1108
1109SPL can access binman symbols at runtime. See:
1110
1111    'Access to binman entry offsets at run time (symbols)'
1112
1113in the binman README for more information.
1114
1115The ELF file 'spl/u-boot-spl' must also be available for this to work, since
1116binman uses that to look up symbols to write into the SPL binary.
1117
1118
1119
1120Entry: u-boot-spl-with-ucode-ptr: U-Boot SPL with embedded microcode pointer
1121----------------------------------------------------------------------------
1122
1123This is used when SPL must set up the microcode for U-Boot.
1124
1125See Entry_u_boot_ucode for full details of the entries involved in this
1126process.
1127
1128
1129
1130Entry: u-boot-tpl: U-Boot TPL binary
1131------------------------------------
1132
1133Properties / Entry arguments:
1134    - filename: Filename of u-boot-tpl.bin (default 'tpl/u-boot-tpl.bin')
1135
1136This is the U-Boot TPL (Tertiary Program Loader) binary. This is a small
1137binary which loads before SPL, typically into on-chip SRAM. It is
1138responsible for locating, loading and jumping to SPL, the next-stage
1139loader. Note that SPL is not relocatable so must be loaded to the correct
1140address in SRAM, or written to run from the correct address if direct
1141flash execution is possible (e.g. on x86 devices).
1142
1143SPL can access binman symbols at runtime. See:
1144
1145    'Access to binman entry offsets at run time (symbols)'
1146
1147in the binman README for more information.
1148
1149The ELF file 'tpl/u-boot-tpl' must also be available for this to work, since
1150binman uses that to look up symbols to write into the TPL binary.
1151
1152Note that this entry is automatically replaced with u-boot-tpl-expanded
1153unless --no-expanded is used or the node has a 'no-expanded' property.
1154
1155
1156
1157Entry: u-boot-tpl-bss-pad: U-Boot TPL binary padded with a BSS region
1158---------------------------------------------------------------------
1159
1160Properties / Entry arguments:
1161    None
1162
1163This holds the padding added after the TPL binary to cover the BSS (Block
1164Started by Symbol) region. This region holds the various variables used by
1165TPL. It is set to 0 by TPL when it starts up. If you want to append data to
1166the TPL image (such as a device tree file), you must pad out the BSS region
1167to avoid the data overlapping with U-Boot variables. This entry is useful in
1168that case. It automatically pads out the entry size to cover both the code,
1169data and BSS.
1170
1171The contents of this entry will a certain number of zero bytes, determined
1172by __bss_size
1173
1174The ELF file 'tpl/u-boot-tpl' must also be available for this to work, since
1175binman uses that to look up the BSS address.
1176
1177
1178
1179Entry: u-boot-tpl-dtb: U-Boot TPL device tree
1180---------------------------------------------
1181
1182Properties / Entry arguments:
1183    - filename: Filename of u-boot.dtb (default 'tpl/u-boot-tpl.dtb')
1184
1185This is the TPL device tree, containing configuration information for
1186TPL. TPL needs this to know what devices are present and which drivers
1187to activate.
1188
1189
1190
1191Entry: u-boot-tpl-dtb-with-ucode: U-Boot TPL with embedded microcode pointer
1192----------------------------------------------------------------------------
1193
1194This is used when TPL must set up the microcode for U-Boot.
1195
1196See Entry_u_boot_ucode for full details of the entries involved in this
1197process.
1198
1199
1200
1201Entry: u-boot-tpl-elf: U-Boot TPL ELF image
1202-------------------------------------------
1203
1204Properties / Entry arguments:
1205    - filename: Filename of TPL u-boot (default 'tpl/u-boot-tpl')
1206
1207This is the U-Boot TPL ELF image. It does not include a device tree but can
1208be relocated to any address for execution.
1209
1210
1211
1212Entry: u-boot-tpl-expanded: U-Boot TPL flat binary broken out into its component parts
1213--------------------------------------------------------------------------------------
1214
1215Properties / Entry arguments:
1216    - tpl-dtb: Controls whether this entry is selected (set to 'y' or '1' to
1217        select)
1218
1219This is a section containing the U-Boot binary, BSS padding if needed and a
1220devicetree. Using this entry type automatically creates this section, with
1221the following entries in it:
1222
1223   u-boot-tpl-nodtb
1224   u-boot-tpl-bss-pad
1225   u-boot-dtb
1226
1227Having the devicetree separate allows binman to update it in the final
1228image, so that the entries positions are provided to the running U-Boot.
1229
1230This entry is selected based on the value of the 'tpl-dtb' entryarg. If
1231this is non-empty (and not 'n' or '0') then this expanded entry is selected.
1232
1233
1234
1235Entry: u-boot-tpl-nodtb: TPL binary without device tree appended
1236----------------------------------------------------------------
1237
1238Properties / Entry arguments:
1239    - filename: Filename to include (default 'tpl/u-boot-tpl-nodtb.bin')
1240
1241This is the U-Boot TPL binary, It does not include a device tree blob at
1242the end of it so may not be able to work without it, assuming TPL needs
1243a device tree to operate on your platform. You can add a u-boot-tpl-dtb
1244entry after this one, or use a u-boot-tpl entry instead, which normally
1245expands to a section containing u-boot-tpl-dtb, u-boot-tpl-bss-pad and
1246u-boot-tpl-dtb
1247
1248TPL can access binman symbols at runtime. See:
1249
1250    'Access to binman entry offsets at run time (symbols)'
1251
1252in the binman README for more information.
1253
1254The ELF file 'tpl/u-boot-tpl' must also be available for this to work, since
1255binman uses that to look up symbols to write into the TPL binary.
1256
1257
1258
1259Entry: u-boot-tpl-with-ucode-ptr: U-Boot TPL with embedded microcode pointer
1260----------------------------------------------------------------------------
1261
1262See Entry_u_boot_ucode for full details of the entries involved in this
1263process.
1264
1265
1266
1267Entry: u-boot-ucode: U-Boot microcode block
1268-------------------------------------------
1269
1270Properties / Entry arguments:
1271    None
1272
1273The contents of this entry are filled in automatically by other entries
1274which must also be in the image.
1275
1276U-Boot on x86 needs a single block of microcode. This is collected from
1277the various microcode update nodes in the device tree. It is also unable
1278to read the microcode from the device tree on platforms that use FSP
1279(Firmware Support Package) binaries, because the API requires that the
1280microcode is supplied before there is any SRAM available to use (i.e.
1281the FSP sets up the SRAM / cache-as-RAM but does so in the call that
1282requires the microcode!). To keep things simple, all x86 platforms handle
1283microcode the same way in U-Boot (even non-FSP platforms). This is that
1284a table is placed at _dt_ucode_base_size containing the base address and
1285size of the microcode. This is either passed to the FSP (for FSP
1286platforms), or used to set up the microcode (for non-FSP platforms).
1287This all happens in the build system since it is the only way to get
1288the microcode into a single blob and accessible without SRAM.
1289
1290There are two cases to handle. If there is only one microcode blob in
1291the device tree, then the ucode pointer it set to point to that. This
1292entry (u-boot-ucode) is empty. If there is more than one update, then
1293this entry holds the concatenation of all updates, and the device tree
1294entry (u-boot-dtb-with-ucode) is updated to remove the microcode. This
1295last step ensures that that the microcode appears in one contiguous
1296block in the image and is not unnecessarily duplicated in the device
1297tree. It is referred to as 'collation' here.
1298
1299Entry types that have a part to play in handling microcode:
1300
1301    Entry_u_boot_with_ucode_ptr:
1302        Contains u-boot-nodtb.bin (i.e. U-Boot without the device tree).
1303        It updates it with the address and size of the microcode so that
1304        U-Boot can find it early on start-up.
1305    Entry_u_boot_dtb_with_ucode:
1306        Contains u-boot.dtb. It stores the microcode in a
1307        'self.ucode_data' property, which is then read by this class to
1308        obtain the microcode if needed. If collation is performed, it
1309        removes the microcode from the device tree.
1310    Entry_u_boot_ucode:
1311        This class. If collation is enabled it reads the microcode from
1312        the Entry_u_boot_dtb_with_ucode entry, and uses it as the
1313        contents of this entry.
1314
1315
1316
1317Entry: u-boot-with-ucode-ptr: U-Boot with embedded microcode pointer
1318--------------------------------------------------------------------
1319
1320Properties / Entry arguments:
1321    - filename: Filename of u-boot-nodtb.bin (default 'u-boot-nodtb.bin')
1322    - optional-ucode: boolean property to make microcode optional. If the
1323        u-boot.bin image does not include microcode, no error will
1324        be generated.
1325
1326See Entry_u_boot_ucode for full details of the three entries involved in
1327this process. This entry updates U-Boot with the offset and size of the
1328microcode, to allow early x86 boot code to find it without doing anything
1329complicated. Otherwise it is the same as the u-boot entry.
1330
1331
1332
1333Entry: vblock: An entry which contains a Chromium OS verified boot block
1334------------------------------------------------------------------------
1335
1336Properties / Entry arguments:
1337    - content: List of phandles to entries to sign
1338    - keydir: Directory containing the public keys to use
1339    - keyblock: Name of the key file to use (inside keydir)
1340    - signprivate: Name of provide key file to use (inside keydir)
1341    - version: Version number of the vblock (typically 1)
1342    - kernelkey: Name of the kernel key to use (inside keydir)
1343    - preamble-flags: Value of the vboot preamble flags (typically 0)
1344
1345Output files:
1346    - input.<unique_name> - input file passed to futility
1347    - vblock.<unique_name> - output file generated by futility (which is
1348        used as the entry contents)
1349
1350Chromium OS signs the read-write firmware and kernel, writing the signature
1351in this block. This allows U-Boot to verify that the next firmware stage
1352and kernel are genuine.
1353
1354
1355
1356Entry: x86-reset16: x86 16-bit reset code for U-Boot
1357----------------------------------------------------
1358
1359Properties / Entry arguments:
1360    - filename: Filename of u-boot-x86-reset16.bin (default
1361        'u-boot-x86-reset16.bin')
1362
1363x86 CPUs start up in 16-bit mode, even if they are 32-bit CPUs. This code
1364must be placed at a particular address. This entry holds that code. It is
1365typically placed at offset CONFIG_RESET_VEC_LOC. The code is responsible
1366for jumping to the x86-start16 code, which continues execution.
1367
1368For 64-bit U-Boot, the 'x86_reset16_spl' entry type is used instead.
1369
1370
1371
1372Entry: x86-reset16-spl: x86 16-bit reset code for U-Boot
1373--------------------------------------------------------
1374
1375Properties / Entry arguments:
1376    - filename: Filename of u-boot-x86-reset16.bin (default
1377        'u-boot-x86-reset16.bin')
1378
1379x86 CPUs start up in 16-bit mode, even if they are 32-bit CPUs. This code
1380must be placed at a particular address. This entry holds that code. It is
1381typically placed at offset CONFIG_RESET_VEC_LOC. The code is responsible
1382for jumping to the x86-start16 code, which continues execution.
1383
1384For 32-bit U-Boot, the 'x86_reset_spl' entry type is used instead.
1385
1386
1387
1388Entry: x86-reset16-tpl: x86 16-bit reset code for U-Boot
1389--------------------------------------------------------
1390
1391Properties / Entry arguments:
1392    - filename: Filename of u-boot-x86-reset16.bin (default
1393        'u-boot-x86-reset16.bin')
1394
1395x86 CPUs start up in 16-bit mode, even if they are 32-bit CPUs. This code
1396must be placed at a particular address. This entry holds that code. It is
1397typically placed at offset CONFIG_RESET_VEC_LOC. The code is responsible
1398for jumping to the x86-start16 code, which continues execution.
1399
1400For 32-bit U-Boot, the 'x86_reset_tpl' entry type is used instead.
1401
1402
1403
1404Entry: x86-start16: x86 16-bit start-up code for U-Boot
1405-------------------------------------------------------
1406
1407Properties / Entry arguments:
1408    - filename: Filename of u-boot-x86-start16.bin (default
1409        'u-boot-x86-start16.bin')
1410
1411x86 CPUs start up in 16-bit mode, even if they are 32-bit CPUs. This code
1412must be placed in the top 64KB of the ROM. The reset code jumps to it. This
1413entry holds that code. It is typically placed at offset
1414CONFIG_SYS_X86_START16. The code is responsible for changing to 32-bit mode
1415and jumping to U-Boot's entry point, which requires 32-bit mode (for 32-bit
1416U-Boot).
1417
1418For 64-bit U-Boot, the 'x86_start16_spl' entry type is used instead.
1419
1420
1421
1422Entry: x86-start16-spl: x86 16-bit start-up code for SPL
1423--------------------------------------------------------
1424
1425Properties / Entry arguments:
1426    - filename: Filename of spl/u-boot-x86-start16-spl.bin (default
1427        'spl/u-boot-x86-start16-spl.bin')
1428
1429x86 CPUs start up in 16-bit mode, even if they are 32-bit CPUs. This code
1430must be placed in the top 64KB of the ROM. The reset code jumps to it. This
1431entry holds that code. It is typically placed at offset
1432CONFIG_SYS_X86_START16. The code is responsible for changing to 32-bit mode
1433and jumping to U-Boot's entry point, which requires 32-bit mode (for 32-bit
1434U-Boot).
1435
1436For 32-bit U-Boot, the 'x86-start16' entry type is used instead.
1437
1438
1439
1440Entry: x86-start16-tpl: x86 16-bit start-up code for TPL
1441--------------------------------------------------------
1442
1443Properties / Entry arguments:
1444    - filename: Filename of tpl/u-boot-x86-start16-tpl.bin (default
1445        'tpl/u-boot-x86-start16-tpl.bin')
1446
1447x86 CPUs start up in 16-bit mode, even if they are 32-bit CPUs. This code
1448must be placed in the top 64KB of the ROM. The reset code jumps to it. This
1449entry holds that code. It is typically placed at offset
1450CONFIG_SYS_X86_START16. The code is responsible for changing to 32-bit mode
1451and jumping to U-Boot's entry point, which requires 32-bit mode (for 32-bit
1452U-Boot).
1453
1454If TPL is not being used, the 'x86-start16-spl or 'x86-start16' entry types
1455may be used instead.
1456
1457
1458
1459