| # 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 |
| |
| import command |
| from entry import Entry, EntryArg |
| |
| import fdt_util |
| 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| but note that the page dates from 2013 so is quite out of date.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): |
| Entry.__init__(self, 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.iteritems(): |
| if fdt_util.GetBool(flags_node, flag): |
| self.gbb_flags |= value |
| |
| def ObtainContents(self): |
| gbb = 'gbb.bin' |
| fname = tools.GetOutputFilename(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)') |
| sizes = [0x100, 0x1000, bmpfv_size, 0x1000] |
| sizes = ['%#x' % size for size in sizes] |
| keydir = tools.GetInputFilename(self.keydir) |
| gbb_set_command = [ |
| 'gbb_utility', '-s', |
| '--hwid=%s' % self.hardware_id, |
| '--rootkey=%s/root_key.vbpubk' % keydir, |
| '--recoverykey=%s/recovery_key.vbpubk' % keydir, |
| '--flags=%d' % self.gbb_flags, |
| '--bmpfv=%s' % tools.GetInputFilename(self.bmpblk), |
| fname] |
| |
| tools.Run('futility', 'gbb_utility', '-c', ','.join(sizes), fname) |
| tools.Run('futility', *gbb_set_command) |
| |
| self.SetContents(tools.ReadFile(fname)) |
| return True |
