x86: Add a script to process Intel microcode files

Intel delivers microcode updates in a microcode.dat file which must be
split up into individual files for each CPU. Add a tool which performs
this task. It can list available microcode updates for each model and
produce a new microcode update in U-Boot's .dtsi format.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Bin Meng <bmeng.cn@gmail.com>

2 files changed, 254 insertions, 0 deletions

diff --git a/tools/microcode-tool b/tools/microcode-tool
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+microcode-tool.py
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diff --git a/tools/microcode-tool.py b/tools/microcode-tool.py
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+++ b/tools/microcode-tool.py
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+#!/usr/bin/env python
+#
+# Copyright (c) 2014 Google, Inc
+#
+# SPDX-License-Identifier:      GPL-2.0+
+#
+# Intel microcode update tool
+
+from optparse import OptionParser
+import os
+import re
+import struct
+import sys
+
+MICROCODE_DIR = 'arch/x86/dts/microcode'
+
+class Microcode:
+    """Holds information about the microcode for a particular model of CPU.
+
+    Attributes:
+        name:  Name of the CPU this microcode is for, including any version
+                   information (e.g. 'm12206a7_00000029')
+        model: Model code string (this is cpuid(1).eax, e.g. '206a7')
+        words: List of hex words containing the microcode. The first 16 words
+                   are the public header.
+    """
+    def __init__(self, name, data):
+        self.name = name
+        # Convert data into a list of hex words
+        self.words = []
+        for value in ''.join(data).split(','):
+            hexval = value.strip()
+            if hexval:
+                self.words.append(int(hexval, 0))
+
+        # The model is in the 4rd hex word
+        self.model = '%x' % self.words[3]
+
+def ParseFile(fname):
+    """Parse a micrcode.dat file and return the component parts
+
+    Args:
+        fname: Filename to parse
+    Returns:
+        3-Tuple:
+            date:         String containing date from the file's header
+            license_text: List of text lines for the license file
+            microcodes:   List of Microcode objects from the file
+    """
+    re_date = re.compile('/\* *(.* [0-9]{4}) *\*/$')
+    re_license = re.compile('/[^-*+] *(.*)$')
+    re_name = re.compile('/\* *(.*)\.inc *\*/', re.IGNORECASE)
+    microcodes = {}
+    license_text = []
+    date = ''
+    data = []
+    name = None
+    with open(fname) as fd:
+        for line in fd:
+            line = line.rstrip()
+            m_date = re_date.match(line)
+            m_license = re_license.match(line)
+            m_name = re_name.match(line)
+            if m_name:
+                if name:
+                    microcodes[name] = Microcode(name, data)
+                name = m_name.group(1).lower()
+                data = []
+            elif m_license:
+                license_text.append(m_license.group(1))
+            elif m_date:
+                date = m_date.group(1)
+            else:
+                data.append(line)
+    if name:
+        microcodes[name] = Microcode(name, data)
+    return date, license_text, microcodes
+
+def List(date, microcodes, model):
+    """List the available microcode chunks
+
+    Args:
+        date:           Date of the microcode file
+        microcodes:     Dict of Microcode objects indexed by name
+        model:          Model string to search for, or None
+    """
+    print 'Date: %s' % date
+    if model:
+        mcode_list, tried = FindMicrocode(microcodes, model.lower())
+        print 'Matching models %s:' % (', '.join(tried))
+    else:
+        print 'All models:'
+        mcode_list = [microcodes[m] for m in microcodes.keys()]
+    for mcode in mcode_list:
+        print '%-20s: model %s' % (mcode.name, mcode.model)
+
+def FindMicrocode(microcodes, model):
+    """Find all the microcode chunks which match the given model.
+
+    This model is something like 306a9 (the value returned in eax from
+    cpuid(1) when running on Intel CPUs). But we allow a partial match,
+    omitting the last 1 or two characters to allow many families to have the
+    same microcode.
+
+    If the model name is ambiguous we return a list of matches.
+
+    Args:
+        microcodes: Dict of Microcode objects indexed by name
+        model:      String containing model name to find
+    Returns:
+        Tuple:
+            List of matching Microcode objects
+            List of abbreviations we tried
+    """
+    # Allow a full name to be used
+    mcode = microcodes.get(model)
+    if mcode:
+        return [mcode], []
+
+    tried = []
+    found = []
+    for i in range(3):
+        abbrev = model[:-i] if i else model
+        tried.append(abbrev)
+        for mcode in microcodes.values():
+            if mcode.model.startswith(abbrev):
+                found.append(mcode)
+        if found:
+            break
+    return found, tried
+
+def CreateFile(date, license_text, mcode, outfile):
+    """Create a microcode file in U-Boot's .dtsi format
+
+    Args:
+        date:       String containing date of original microcode file
+        license:    List of text lines for the license file
+        mcode:      Microcode object to write
+        outfile:    Filename to write to ('-' for stdout)
+    """
+    out = '''/*%s
+ * ---
+ * This is a device tree fragment. Use #include to add these properties to a
+ * node.
+ *
+ * Date: %s
+ */
+
+compatible = "intel,microcode";
+intel,header-version = <%d>;
+intel,update-revision = <%#x>;
+intel,date-code = <%#x>;
+intel,processor-signature = <%#x>;
+intel,checksum = <%#x>;
+intel,loader-revision = <%d>;
+intel,processor-flags = <%#x>;
+
+/* The first 48-bytes are the public header which repeats the above data */
+data = <%s
+\t>;'''
+    words = ''
+    for i in range(len(mcode.words)):
+        if not (i & 3):
+            words += '\n'
+        val = mcode.words[i]
+        # Change each word so it will be little-endian in the FDT
+        # This data is needed before RAM is available on some platforms so we
+        # cannot do an endianness swap on boot.
+        val = struct.unpack("<I", struct.pack(">I", val))[0]
+        words += '\t%#010x' % val
+
+    # Take care to avoid adding a space before a tab
+    text = ''
+    for line in license_text:
+        if line[0] == '\t':
+            text += '\n *' + line
+        else:
+            text += '\n * ' + line
+    args = [text, date]
+    args += [mcode.words[i] for i in range(7)]
+    args.append(words)
+    if outfile == '-':
+        print out % tuple(args)
+    else:
+        if not outfile:
+            if not os.path.exists(MICROCODE_DIR):
+                print >> sys.stderr, "Creating directory '%s'" % MICROCODE_DIR
+                os.makedirs(MICROCODE_DIR)
+            outfile = os.path.join(MICROCODE_DIR, mcode.name + '.dtsi')
+            print >> sys.stderr, "Writing microcode for '%s' to '%s'" % (
+                     mcode.name, outfile)
+        with open(outfile, 'w') as fd:
+            print >> fd, out % tuple(args)
+
+def MicrocodeTool():
+    """Run the microcode tool"""
+    commands = 'create,license,list'.split(',')
+    parser = OptionParser()
+    parser.add_option('-d', '--mcfile', type='string', action='store',
+                    help='Name of microcode.dat file')
+    parser.add_option('-m', '--model', type='string', action='store',
+                    help='Model name to extract')
+    parser.add_option('-o', '--outfile', type='string', action='store',
+                    help='Filename to use for output (- for stdout), default is'
+                    ' %s/<name>.dtsi' % MICROCODE_DIR)
+    parser.usage += """ command
+
+    Process an Intel microcode file (use -h for help). Commands:
+
+       create     Create microcode .dtsi file for a model
+       list       List available models in microcode file
+       license    Print the license
+
+    Typical usage:
+
+       ./tools/microcode-tool -d microcode.dat -m 306a create
+
+    This will find the appropriate file and write it to %s.""" % MICROCODE_DIR
+
+    (options, args) = parser.parse_args()
+    if not args:
+        parser.error('Please specify a command')
+    cmd = args[0]
+    if cmd not in commands:
+        parser.error("Unknown command '%s'" % cmd)
+
+    if not options.mcfile:
+        parser.error('You must specify a microcode file')
+    date, license_text, microcodes = ParseFile(options.mcfile)
+
+    if cmd == 'list':
+        List(date, microcodes, options.model)
+    elif cmd == 'license':
+        print '\n'.join(license_text)
+    elif cmd == 'create':
+        if not options.model:
+            parser.error('You must specify a model to create')
+        model = options.model.lower()
+        mcode_list, tried = FindMicrocode(microcodes, model)
+        if not mcode_list:
+            parser.error("Unknown model '%s' (%s) - try 'list' to list" %
+                        (model, ', '.join(tried)))
+        if len(mcode_list) > 1:
+            parser.error("Ambiguous model '%s' (%s) matched %s - try 'list' "
+                        "to list or specify a particular file" %
+                        (model, ', '.join(tried),
+                        ', '.join([m.name for m in mcode_list])))
+        CreateFile(date, license_text, mcode_list[0], options.outfile)
+    else:
+        parser.error("Unknown command '%s'" % cmd)
+
+if __name__ == "__main__":
+    MicrocodeTool()