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diff --git a/tools/binman/README.entries b/tools/binman/README.entries new file mode 100644 index 0000000000..60cb2488c0 --- /dev/null +++ b/tools/binman/README.entries @@ -0,0 +1,448 @@ +Binman Entry Documentation +=========================== + +This file describes the entry types supported by binman. These entry types can +be placed in an image one by one to build up a final firmware image. It is +fairly easy to create new entry types. Just add a new file to the 'etype' +directory. You can use the existing entries as examples. + +Note that some entries are subclasses of others, using and extending their +features to produce new behaviours. + + + +Entry: blob: Entry containing an arbitrary binary blob +------------------------------------------------------ + +Note: This should not be used by itself. It is normally used as a parent +class by other entry types. + +Properties / Entry arguments: + - filename: Filename of file to read into entry + +This entry reads data from a file and places it in the entry. The +default filename is often specified specified by the subclass. See for +example the 'u_boot' entry which provides the filename 'u-boot.bin'. + + + +Entry: intel-cmc: Entry containing an Intel Chipset Micro Code (CMC) file +------------------------------------------------------------------------- + +Properties / Entry arguments: + - filename: Filename of file to read into entry + +This file contains microcode for some devices in a special format. An +example filename is 'Microcode/C0_22211.BIN'. + +See README.x86 for information about x86 binary blobs. + + + +Entry: intel-descriptor: Intel flash descriptor block (4KB) +----------------------------------------------------------- + +Properties / Entry arguments: + filename: Filename of file containing the descriptor. This is typically + a 4KB binary file, sometimes called 'descriptor.bin' + +This entry is placed at the start of flash and provides information about +the SPI flash regions. In particular it provides the base address and +size of the ME (Management Engine) region, allowing us to place the ME +binary in the right place. + +With this entry in your image, the position of the 'intel-me' entry will be +fixed in the image, which avoids you needed to specify an offset for that +region. This is useful, because it is not possible to change the position +of the ME region without updating the descriptor. + +See README.x86 for information about x86 binary blobs. + + + +Entry: intel-fsp: Entry containing an Intel Firmware Support Package (FSP) file +------------------------------------------------------------------------------- + +Properties / Entry arguments: + - filename: Filename of file to read into entry + +This file contains binary blobs which are used on some devices to make the +platform work. U-Boot executes this code since it is not possible to set up +the hardware using U-Boot open-source code. Documentation is typically not +available in sufficient detail to allow this. + +An example filename is 'FSP/QUEENSBAY_FSP_GOLD_001_20-DECEMBER-2013.fd' + +See README.x86 for information about x86 binary blobs. + + + +Entry: intel-me: Entry containing an Intel Management Engine (ME) file +---------------------------------------------------------------------- + +Properties / Entry arguments: + - filename: Filename of file to read into entry + +This file contains code used by the SoC that is required to make it work. +The Management Engine is like a background task that runs things that are +not clearly documented, but may include keyboard, deplay and network +access. For platform that use ME it is not possible to disable it. U-Boot +does not directly execute code in the ME binary. + +A typical filename is 'me.bin'. + +See README.x86 for information about x86 binary blobs. + + + +Entry: intel-mrc: Entry containing an Intel Memory Reference Code (MRC) file +---------------------------------------------------------------------------- + +Properties / Entry arguments: + - filename: Filename of file to read into entry + +This file contains code for setting up the SDRAM on some Intel systems. This +is executed by U-Boot when needed early during startup. A typical filename +is 'mrc.bin'. + +See README.x86 for information about x86 binary blobs. + + + +Entry: intel-vbt: Entry containing an Intel Video BIOS Table (VBT) file +----------------------------------------------------------------------- + +Properties / Entry arguments: + - filename: Filename of file to read into entry + +This file contains code that sets up the integrated graphics subsystem on +some Intel SoCs. U-Boot executes this when the display is started up. + +See README.x86 for information about Intel binary blobs. + + + +Entry: intel-vga: Entry containing an Intel Video Graphics Adaptor (VGA) file +----------------------------------------------------------------------------- + +Properties / Entry arguments: + - filename: Filename of file to read into entry + +This file contains code that sets up the integrated graphics subsystem on +some Intel SoCs. U-Boot executes this when the display is started up. + +This is similar to the VBT file but in a different format. + +See README.x86 for information about Intel binary blobs. + + + +Entry: section: Entry that contains other entries +------------------------------------------------- + +Properties / Entry arguments: (see binman README for more information) + - size: Size of section in bytes + - align-size: Align size to a particular power of two + - pad-before: Add padding before the entry + - pad-after: Add padding after the entry + - pad-byte: Pad byte to use when padding + - sort-by-offset: Reorder the entries by offset + - end-at-4gb: Used to build an x86 ROM which ends at 4GB (2^32) + - name-prefix: Adds a prefix to the name of every entry in the section + when writing out the map + +A section is an entry which can contain other entries, thus allowing +hierarchical images to be created. See 'Sections and hierarchical images' +in the binman README for more information. + + + +Entry: text: An entry which contains text +----------------------------------------- + +The text can be provided either in the node itself or by a command-line +argument. There is a level of indirection to allow multiple text strings +and sharing of text. + +Properties / Entry arguments: + text-label: The value of this string indicates the property / entry-arg + that contains the string to place in the entry + <xxx> (actual name is the value of text-label): contains the string to + place in the entry. + +Example node: + + text { + size = <50>; + text-label = "message"; + }; + +You can then use: + + binman -amessage="this is my message" + +and binman will insert that string into the entry. + +It is also possible to put the string directly in the node: + + text { + size = <8>; + text-label = "message"; + message = "a message directly in the node" + }; + +The text is not itself nul-terminated. This can be achieved, if required, +by setting the size of the entry to something larger than the text. + + + +Entry: u-boot: U-Boot flat binary +--------------------------------- + +Properties / Entry arguments: + - filename: Filename of u-boot.bin (default 'u-boot.bin') + +This is the U-Boot binary, containing relocation information to allow it +to relocate itself at runtime. The binary typically includes a device tree +blob at the end of it. Use u_boot_nodtb if you want to package the device +tree separately. + +U-Boot can access binman symbols at runtime. See: + + 'Access to binman entry offsets at run time (fdt)' + +in the binman README for more information. + + + +Entry: u-boot-dtb: U-Boot device tree +------------------------------------- + +Properties / Entry arguments: + - filename: Filename of u-boot.dtb (default 'u-boot.dtb') + +This is the U-Boot device tree, containing configuration information for +U-Boot. U-Boot needs this to know what devices are present and which drivers +to activate. + + + +Entry: u-boot-dtb-with-ucode: A U-Boot device tree file, with the microcode removed +----------------------------------------------------------------------------------- + +Properties / Entry arguments: + - filename: Filename of u-boot.dtb (default 'u-boot.dtb') + +See Entry_u_boot_ucode for full details of the three entries involved in +this process. This entry provides the U-Boot device-tree file, which +contains the microcode. If the microcode is not being collated into one +place then the offset and size of the microcode is recorded by this entry, +for use by u_boot_with_ucode_ptr. If it is being collated, then this +entry deletes the microcode from the device tree (to save space) and makes +it available to u_boot_ucode. + + + +Entry: u-boot-img: U-Boot legacy image +-------------------------------------- + +Properties / Entry arguments: + - filename: Filename of u-boot.img (default 'u-boot.img') + +This is the U-Boot binary as a packaged image, in legacy format. It has a +header which allows it to be loaded at the correct address for execution. + +You should use FIT (Flat Image Tree) instead of the legacy image for new +applications. + + + +Entry: u-boot-nodtb: U-Boot flat binary without device tree appended +-------------------------------------------------------------------- + +Properties / Entry arguments: + - filename: Filename of u-boot.bin (default 'u-boot-nodtb.bin') + +This is the U-Boot binary, containing relocation information to allow it +to relocate itself at runtime. It does not include a device tree blob at +the end of it so normally cannot work without it. You can add a u_boot_dtb +entry after this one, or use a u_boot entry instead (which contains both +U-Boot and the device tree). + + + +Entry: u-boot-spl: U-Boot SPL binary +------------------------------------ + +Properties / Entry arguments: + - filename: Filename of u-boot-spl.bin (default 'spl/u-boot-spl.bin') + +This is the U-Boot SPL (Secondary Program Loader) binary. This is a small +binary which loads before U-Boot proper, typically into on-chip SRAM. It is +responsible for locating, loading and jumping to U-Boot. Note that SPL is +not relocatable so must be loaded to the correct address in SRAM, or written +to run from the correct address is direct flash execution is possible (e.g. +on x86 devices). + +SPL can access binman symbols at runtime. See: + + 'Access to binman entry offsets at run time (symbols)' + +in the binman README for more information. + +The ELF file 'spl/u-boot-spl' must also be available for this to work, since +binman uses that to look up symbols to write into the SPL binary. + + + +Entry: u-boot-spl-bss-pad: U-Boot SPL binary padded with a BSS region +--------------------------------------------------------------------- + +Properties / Entry arguments: + None + +This is similar to u_boot_spl except that padding is added after the SPL +binary to cover the BSS (Block Started by Symbol) region. This region holds +the various used by SPL. It is set to 0 by SPL when it starts up. If you +want to append data to the SPL image (such as a device tree file), you must +pad out the BSS region to avoid the data overlapping with U-Boot variables. +This entry is useful in that case. It automatically pads out the entry size +to cover both the code, data and BSS. + +The ELF file 'spl/u-boot-spl' must also be available for this to work, since +binman uses that to look up the BSS address. + + + +Entry: u-boot-spl-dtb: U-Boot SPL device tree +--------------------------------------------- + +Properties / Entry arguments: + - filename: Filename of u-boot.dtb (default 'spl/u-boot-spl.dtb') + +This is the SPL device tree, containing configuration information for +SPL. SPL needs this to know what devices are present and which drivers +to activate. + + + +Entry: u-boot-spl-nodtb: SPL binary without device tree appended +---------------------------------------------------------------- + +Properties / Entry arguments: + - filename: Filename of spl/u-boot-spl-nodtb.bin (default + 'spl/u-boot-spl-nodtb.bin') + +This is the U-Boot SPL binary, It does not include a device tree blob at +the end of it so may not be able to work without it, assuming SPL needs +a device tree to operation on your platform. You can add a u_boot_spl_dtb +entry after this one, or use a u_boot_spl entry instead (which contains +both SPL and the device tree). + + + +Entry: u-boot-spl-with-ucode-ptr: U-Boot SPL with embedded microcode pointer +---------------------------------------------------------------------------- + +See Entry_u_boot_ucode for full details of the entries involved in this +process. + + + +Entry: u-boot-ucode: U-Boot microcode block +------------------------------------------- + +Properties / Entry arguments: + None + +The contents of this entry are filled in automatically by other entries +which must also be in the image. + +U-Boot on x86 needs a single block of microcode. This is collected from +the various microcode update nodes in the device tree. It is also unable +to read the microcode from the device tree on platforms that use FSP +(Firmware Support Package) binaries, because the API requires that the +microcode is supplied before there is any SRAM available to use (i.e. +the FSP sets up the SRAM / cache-as-RAM but does so in the call that +requires the microcode!). To keep things simple, all x86 platforms handle +microcode the same way in U-Boot (even non-FSP platforms). This is that +a table is placed at _dt_ucode_base_size containing the base address and +size of the microcode. This is either passed to the FSP (for FSP +platforms), or used to set up the microcode (for non-FSP platforms). +This all happens in the build system since it is the only way to get +the microcode into a single blob and accessible without SRAM. + +There are two cases to handle. If there is only one microcode blob in +the device tree, then the ucode pointer it set to point to that. This +entry (u-boot-ucode) is empty. If there is more than one update, then +this entry holds the concatenation of all updates, and the device tree +entry (u-boot-dtb-with-ucode) is updated to remove the microcode. This +last step ensures that that the microcode appears in one contiguous +block in the image and is not unnecessarily duplicated in the device +tree. It is referred to as 'collation' here. + +Entry types that have a part to play in handling microcode: + + Entry_u_boot_with_ucode_ptr: + Contains u-boot-nodtb.bin (i.e. U-Boot without the device tree). + It updates it with the address and size of the microcode so that + U-Boot can find it early on start-up. + Entry_u_boot_dtb_with_ucode: + Contains u-boot.dtb. It stores the microcode in a + 'self.ucode_data' property, which is then read by this class to + obtain the microcode if needed. If collation is performed, it + removes the microcode from the device tree. + Entry_u_boot_ucode: + This class. If collation is enabled it reads the microcode from + the Entry_u_boot_dtb_with_ucode entry, and uses it as the + contents of this entry. + + + +Entry: u-boot-with-ucode-ptr: U-Boot with embedded microcode pointer +-------------------------------------------------------------------- + +Properties / Entry arguments: + - filename: Filename of u-boot-nodtb.dtb (default 'u-boot-nodtb.dtb') + +See Entry_u_boot_ucode for full details of the three entries involved in +this process. This entry updates U-Boot with the offset and size of the +microcode, to allow early x86 boot code to find it without doing anything +complicated. Otherwise it is the same as the u_boot entry. + + + +Entry: x86-start16: x86 16-bit start-up code for U-Boot +------------------------------------------------------- + +Properties / Entry arguments: + - filename: Filename of u-boot-x86-16bit.bin (default + 'u-boot-x86-16bit.bin') + +x86 CPUs start up in 16-bit mode, even if they are 32-bit CPUs. This code +must be placed at a particular address. This entry holds that code. It is +typically placed at offset CONFIG_SYS_X86_START16. The code is responsible +for changing to 32-bit mode and jumping to U-Boot's entry point, which +requires 32-bit mode (for 32-bit U-Boot). + +For 64-bit U-Boot, the 'x86_start16_spl' entry type is used instead. + + + +Entry: x86-start16-spl: x86 16-bit start-up code for SPL +-------------------------------------------------------- + +Properties / Entry arguments: + - filename: Filename of spl/u-boot-x86-16bit-spl.bin (default + 'spl/u-boot-x86-16bit-spl.bin') + +x86 CPUs start up in 16-bit mode, even if they are 64-bit CPUs. This code +must be placed at a particular address. This entry holds that code. It is +typically placed at offset CONFIG_SYS_X86_START16. The code is responsible +for changing to 32-bit mode and starting SPL, which in turn changes to +64-bit mode and jumps to U-Boot (for 64-bit U-Boot). + +For 32-bit U-Boot, the 'x86_start16' entry type is used instead. + + + |