1# SPDX-License-Identifier: GPL-2.0+
2# Copyright (c) 2016 Google, Inc
3# Written by Simon Glass <sjg@chromium.org>
4#
5# Entry-type module for a U-Boot binary with an embedded microcode pointer
6#
7
8import struct
9
10import command
11import elf
12from entry import Entry
13from blob import Entry_blob
14import fdt_util
15import tools
16
17class Entry_u_boot_with_ucode_ptr(Entry_blob):
18    """U-Boot with embedded microcode pointer
19
20    See Entry_u_boot_ucode for full details of the 3 entries involved in this
21    process.
22    """
23    def __init__(self, image, etype, node):
24        Entry_blob.__init__(self, image, etype, node)
25        self.elf_fname = 'u-boot'
26        self.target_pos = None
27
28    def GetDefaultFilename(self):
29        return 'u-boot-nodtb.bin'
30
31    def ObtainContents(self):
32        # Figure out where to put the microcode pointer
33        fname = tools.GetInputFilename(self.elf_fname)
34        sym = elf.GetSymbolAddress(fname, '_dt_ucode_base_size')
35        if sym:
36           self.target_pos = sym
37        elif not fdt_util.GetBool(self._node, 'optional-ucode'):
38            self.Raise('Cannot locate _dt_ucode_base_size symbol in u-boot')
39
40        return Entry_blob.ObtainContents(self)
41
42    def ProcessContents(self):
43        # If the image does not need microcode, there is nothing to do
44        if not self.target_pos:
45            return
46
47        # Get the position of the microcode
48        ucode_entry = self.image.FindEntryType('u-boot-ucode')
49        if not ucode_entry:
50            self.Raise('Cannot find microcode region u-boot-ucode')
51
52        # Check the target pos is in the image. If it is not, then U-Boot is
53        # being linked incorrectly, or is being placed at the wrong position
54        # in the image.
55        #
56        # The image must be set up so that U-Boot is placed at the
57        # flash address to which it is linked. For example, if
58        # CONFIG_SYS_TEXT_BASE is 0xfff00000, and the ROM is 8MB, then
59        # the U-Boot region must start at position 7MB in the image. In this
60        # case the ROM starts at 0xff800000, so the position of the first
61        # entry in the image corresponds to that.
62        if (self.target_pos < self.pos or
63                self.target_pos >= self.pos + self.size):
64            self.Raise('Microcode pointer _dt_ucode_base_size at %08x is '
65                'outside the image ranging from %08x to %08x' %
66                (self.target_pos, self.pos, self.pos + self.size))
67
68        # Get the microcode, either from u-boot-ucode or u-boot-dtb-with-ucode.
69        # If we have left the microcode in the device tree, then it will be
70        # in the former. If we extracted the microcode from the device tree
71        # and collated it in one place, it will be in the latter.
72        if ucode_entry.size:
73            pos, size = ucode_entry.pos, ucode_entry.size
74        else:
75            dtb_entry = self.image.FindEntryType('u-boot-dtb-with-ucode')
76            if not dtb_entry:
77                self.Raise('Cannot find microcode region u-boot-dtb-with-ucode')
78            pos = dtb_entry.pos + dtb_entry.ucode_offset
79            size = dtb_entry.ucode_size
80
81        # Write the microcode position and size into the entry
82        pos_and_size = struct.pack('<2L', pos, size)
83        self.target_pos -= self.pos
84        self.data = (self.data[:self.target_pos] + pos_and_size +
85                     self.data[self.target_pos + 8:])
86