# SPDX-License-Identifier: GPL-2.0+ # Copyright 2019 Google LLC # Written by Simon Glass # # Entry-type module for the ARM Trusted Firmware's Firmware Image Package (FIP) # format from collections import OrderedDict from binman.entry import Entry from binman.etype.section import Entry_section from binman.fip_util import FIP_TYPES, FipReader, FipWriter, UUID_LEN from dtoc import fdt_util from u_boot_pylib import tools class Entry_atf_fip(Entry_section): """ARM Trusted Firmware's Firmware Image Package (FIP) A FIP_ provides a way to group binaries in a firmware image, used by ARM's Trusted Firmware A (TF-A) code. It is a simple format consisting of a table of contents with information about the type, offset and size of the binaries in the FIP. It is quite similar to FMAP, with the major difference that it uses UUIDs to indicate the type of each entry. Note: It is recommended to always add an fdtmap to every image, as well as any FIPs so that binman and other tools can access the entire image correctly. The UUIDs correspond to useful names in `fiptool`, provided by ATF to operate on FIPs. Binman uses these names to make it easier to understand what is going on, although it is possible to provide a UUID if needed. The contents of the FIP are defined by subnodes of the atf-fip entry, e.g.:: atf-fip { soc-fw { filename = "bl31.bin"; }; scp-fwu-cfg { filename = "bl2u.bin"; }; u-boot { fip-type = "nt-fw"; }; }; This describes a FIP with three entries: soc-fw, scp-fwu-cfg and nt-fw. You can use normal (non-external) binaries like U-Boot simply by adding a FIP type, with the `fip-type` property, as above. Since FIP exists to bring blobs together, Binman assumes that all FIP entries are external binaries. If a binary may not exist, you can use the `--allow-missing` flag to Binman, in which case the image is still created, even though it will not actually work. The size of the FIP depends on the size of the binaries. There is currently no way to specify a fixed size. If the `atf-fip` node has a `size` entry, this affects the space taken up by the `atf-fip` entry, but the FIP itself does not expand to use that space. Some other FIP features are available with Binman. The header and the entries have 64-bit flag works. The flag flags do not seem to be defined anywhere, but you can use `fip-hdr-flags` and fip-flags` to set the values of the header and entries respectively. FIP entries can be aligned to a particular power-of-two boundary. Use fip-align for this. Binman only understands the entry types that are included in its implementation. It is possible to specify a 16-byte UUID instead, using the fip-uuid property. In this case Binman doesn't know what its type is, so just uses the UUID. See the `u-boot` node in this example:: binman { atf-fip { fip-hdr-flags = /bits/ 64 <0x123>; fip-align = <16>; soc-fw { fip-flags = /bits/ 64 <0x456>; filename = "bl31.bin"; }; scp-fwu-cfg { filename = "bl2u.bin"; }; u-boot { fip-uuid = [fc 65 13 92 4a 5b 11 ec 94 35 ff 2d 1c fc 79 9c]; }; }; fdtmap { }; }; Binman allows reading and updating FIP entries after the image is created, provided that an FDPMAP is present too. Updates which change the size of a FIP entry will cause it to be expanded or contracted as needed. Properties for top-level atf-fip node ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fip-hdr-flags (64 bits) Sets the flags for the FIP header. Properties for subnodes ~~~~~~~~~~~~~~~~~~~~~~~ fip-type (str) FIP type to use for this entry. This is needed if the entry name is not a valid type. Value types are defined in `fip_util.py`. The FIP type defines the UUID that is used (they map 1:1). fip-uuid (16 bytes) If there is no FIP-type name defined, or it is not supported by Binman, this property sets the UUID. It should be a 16-byte value, following the hex digits of the UUID. fip-flags (64 bits) Set the flags for a FIP entry. Use in one of the subnodes of the 7atf-fip entry. fip-align Set the alignment for a FIP entry, FIP entries can be aligned to a particular power-of-two boundary. The default is 1. Adding new FIP-entry types ~~~~~~~~~~~~~~~~~~~~~~~~~~ When new FIP entries are defined by TF-A they appear in the `TF-A source tree`_. You can use `fip_util.py` to update Binman to support new types, then `send a patch`_ to the U-Boot mailing list. There are two source files that the tool examples: - `include/tools_share/firmware_image_package.h` has the UUIDs - `tools/fiptool/tbbr_config.c` has the name and descripion for each UUID To run the tool:: $ tools/binman/fip_util.py -s /path/to/arm-trusted-firmware Warning: UUID 'UUID_NON_TRUSTED_WORLD_KEY_CERT' is not mentioned in tbbr_config.c file Existing code in 'tools/binman/fip_util.py' is up-to-date If it shows there is an update, it writes a new version of `fip_util.py` to `fip_util.py.out`. You can change the output file using the `-i` flag. If you have a problem, use `-D` to enable traceback debugging. FIP commentary ~~~~~~~~~~~~~~ As a side effect of use of UUIDs, FIP does not support multiple entries of the same type, such as might be used to store fonts or graphics icons, for example. For verified boot it could be used for each part of the image (e.g. separate FIPs for A and B) but cannot describe the whole firmware image. As with FMAP there is no hierarchy defined, although FMAP works around this by having 'section' areas which encompass others. A similar workaround would be possible with FIP but is not currently defined. It is recommended to always add an fdtmap to every image, as well as any FIPs so that binman and other tools can access the entire image correctly. .. _FIP: https://trustedfirmware-a.readthedocs.io/en/latest/design/firmware-design.html#firmware-image-package-fip .. _`TF-A source tree`: https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git .. _`send a patch`: https://www.denx.de/wiki/U-Boot/Patches """ def __init__(self, section, etype, node): # Put this here to allow entry-docs and help to work without libfdt global state from binman import state super().__init__(section, etype, node) self.align_default = None self._entries = OrderedDict() self.reader = None def ReadNode(self): """Read properties from the atf-fip node""" super().ReadNode() self._pad_byte = fdt_util.GetInt(self._node, 'pad-byte', 0) self._fip_flags = fdt_util.GetInt64(self._node, 'fip-hdr-flags', 0) self._fip_align = fdt_util.GetInt(self._node, 'fip-align', 1) if tools.not_power_of_two(self._fip_align): raise ValueError("Node '%s': FIP alignment %s must be a power of two" % (self._node.path, self._fip_align)) self.ReadEntries() def ReadEntries(self): """Read the subnodes to find out what should go in this FIP""" for node in self._node.subnodes: fip_type = None etype = None if node.name in FIP_TYPES: fip_type = node.name etype = 'blob-ext' entry = Entry.Create(self, node, etype) entry._fip_uuid = fdt_util.GetBytes(node, 'fip-uuid', UUID_LEN) if not fip_type and not entry._fip_uuid: fip_type = fdt_util.GetString(node, 'fip-type') if not fip_type: self.Raise("Must provide a fip-type (node name '%s' is not a known FIP type)" % node.name) entry._fip_type = fip_type entry._fip_flags = fdt_util.GetInt64(node, 'fip-flags', 0) entry.ReadNode() entry._fip_name = node.name self._entries[entry._fip_name] = entry def BuildSectionData(self, required): """Override this function to create a custom format for the entries Arguments: required (bool): True if the data must be valid, False if it may be missing (entry.GetData() returns None Returns: bytes: Data obtained, or None if None """ fip = FipWriter(self._fip_flags, self._fip_align) for entry in self._entries.values(): # First get the input data and put it in an entry. If not available, # try later. entry_data = entry.GetData(required) if not required and entry_data is None: return None fent = fip.add_entry(entry._fip_type or entry._fip_uuid, entry_data, entry._fip_flags) if fent: entry._fip_entry = fent data = fip.get_data() return data def SetImagePos(self, image_pos): """Override this function to set all the entry properties from FIP We can only do this once image_pos is known Args: image_pos: Position of this entry in the image """ super().SetImagePos(image_pos) # Now update the entries with info from the FIP entries for entry in self._entries.values(): fent = entry._fip_entry entry.size = fent.size entry.offset = fent.offset entry.image_pos = self.image_pos + entry.offset def ReadChildData(self, child, decomp=True, alt_format=None): if not self.reader: self.fip_data = super().ReadData(True) self.reader = FipReader(self.fip_data) reader = self.reader # It is tricky to obtain the data from a FIP entry since it is indexed # by its UUID. fent = reader.get_entry(child._fip_type or child._fip_uuid) return fent.data # Note: # It is also possible to extract it using the offsets directly, but this # seems less FIP_friendly: # return self.fip_data[child.offset:child.offset + child.size] def WriteChildData(self, child): # Recreate the data structure, leaving the data for this child alone, # so that child.data is used to pack into the FIP. self.ObtainContents(skip_entry=child) return super().WriteChildData(child)