| # SPDX-License-Identifier: GPL-2.0+ |
| # Copyright (c) 2018 Google, Inc |
| # Written by Simon Glass <sjg@chromium.org> |
| # |
| |
| # Support for a Chromium OS Google Binary Block, used to record read-only |
| # information mostly used by firmware. |
| |
| from collections import OrderedDict |
| |
| from u_boot_pylib import command |
| from binman.entry import Entry, EntryArg |
| |
| from dtoc import fdt_util |
| from u_boot_pylib import tools |
| |
| # Build GBB flags. |
| # (src/platform/vboot_reference/firmware/include/gbb_header.h) |
| gbb_flag_properties = { |
| 'dev-screen-short-delay': 0x1, |
| 'load-option-roms': 0x2, |
| 'enable-alternate-os': 0x4, |
| 'force-dev-switch-on': 0x8, |
| 'force-dev-boot-usb': 0x10, |
| 'disable-fw-rollback-check': 0x20, |
| 'enter-triggers-tonorm': 0x40, |
| 'force-dev-boot-legacy': 0x80, |
| 'faft-key-override': 0x100, |
| 'disable-ec-software-sync': 0x200, |
| 'default-dev-boot-legacy': 0x400, |
| 'disable-pd-software-sync': 0x800, |
| 'disable-lid-shutdown': 0x1000, |
| 'force-dev-boot-fastboot-full-cap': 0x2000, |
| 'enable-serial': 0x4000, |
| 'disable-dwmp': 0x8000, |
| } |
| |
| |
| class Entry_gbb(Entry): |
| """An entry which contains a Chromium OS Google Binary Block |
| |
| Properties / Entry arguments: |
| - hardware-id: Hardware ID to use for this build (a string) |
| - keydir: Directory containing the public keys to use |
| - bmpblk: Filename containing images used by recovery |
| |
| Chromium OS uses a GBB to store various pieces of information, in particular |
| the root and recovery keys that are used to verify the boot process. Some |
| more details are here: |
| |
| https://www.chromium.org/chromium-os/firmware-porting-guide/2-concepts |
| |
| but note that the page dates from 2013 so is quite out of date. See |
| README.chromium for how to obtain the required keys and tools. |
| """ |
| def __init__(self, section, etype, node): |
| super().__init__(section, etype, node) |
| self.hardware_id, self.keydir, self.bmpblk = self.GetEntryArgsOrProps( |
| [EntryArg('hardware-id', str), |
| EntryArg('keydir', str), |
| EntryArg('bmpblk', str)]) |
| |
| # Read in the GBB flags from the config |
| self.gbb_flags = 0 |
| flags_node = node.FindNode('flags') |
| if flags_node: |
| for flag, value in gbb_flag_properties.items(): |
| if fdt_util.GetBool(flags_node, flag): |
| self.gbb_flags |= value |
| |
| def ObtainContents(self): |
| gbb = 'gbb.bin' |
| fname = tools.get_output_filename(gbb) |
| if not self.size: |
| self.Raise('GBB must have a fixed size') |
| gbb_size = self.size |
| bmpfv_size = gbb_size - 0x2180 |
| if bmpfv_size < 0: |
| self.Raise('GBB is too small (minimum 0x2180 bytes)') |
| keydir = tools.get_input_filename(self.keydir) |
| |
| stdout = self.futility.gbb_create( |
| fname, [0x100, 0x1000, bmpfv_size, 0x1000]) |
| if stdout is not None: |
| stdout = self.futility.gbb_set( |
| fname, |
| hwid=self.hardware_id, |
| rootkey='%s/root_key.vbpubk' % keydir, |
| recoverykey='%s/recovery_key.vbpubk' % keydir, |
| flags=self.gbb_flags, |
| bmpfv=tools.get_input_filename(self.bmpblk)) |
| |
| if stdout is not None: |
| self.SetContents(tools.read_file(fname)) |
| else: |
| # Bintool is missing; just use the required amount of zero data |
| self.record_missing_bintool(self.futility) |
| self.SetContents(tools.get_bytes(0, gbb_size)) |
| |
| return True |
| |
| def AddBintools(self, btools): |
| super().AddBintools(btools) |
| self.futility = self.AddBintool(btools, 'futility') |
