#CHIPSEC: Platform Security Assessment Framework
#Copyright (c) 2010-2021, Intel Corporation
#
#This program is free software; you can redistribute it and/or
#modify it under the terms of the GNU General Public License
#as published by the Free Software Foundation; Version 2.
#
#This program is distributed in the hope that it will be useful,
#but WITHOUT ANY WARRANTY; without even the implied warranty of
#MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#GNU General Public License for more details.
#
#You should have received a copy of the GNU General Public License
#along with this program; if not, write to the Free Software
#Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
#Contact information:
#chipsec@intel.com
#

"""
>>> chipsec_util spd detect
>>> chipsec_util spd dump [device_addr]
>>> chipsec_util spd read <device_addr> <offset>
>>> chipsec_util spd write <device_addr> <offset> <byte_val>

Examples:

>>> chipsec_util spd detect
>>> chipsec_util spd dump DIMM0
>>> chipsec_util spd dump 0xA0
>>> chipsec_util spd read DIMM2 0x0
>>> chipsec_util spd read 0xA0 0x0
>>> chipsec_util spd write 0xA0 0x0 0xAA
"""

import time

from chipsec.command  import BaseCommand
from chipsec.hal      import smbus, spd
from argparse         import ArgumentParser


class SPDCommand(BaseCommand):

    def requires_driver(self):
        parser = ArgumentParser(usage=__doc__)
        subparsers = parser.add_subparsers()

        parser_detect = subparsers.add_parser('detect')
        parser_detect.set_defaults(func=self.spd_detect)

        parser_dump = subparsers.add_parser('dump')
        parser_dump.add_argument('dev', type=str, nargs='?', default=None, help="Device")
        parser_dump.set_defaults(func=self.spd_dump)

        parser_read = subparsers.add_parser('read')
        parser_read.add_argument('dev', type=str, help="Device Address")
        parser_read.add_argument('off', type=lambda x: int(x, 16), nargs='?', default=None, help="Offset (hex)")
        parser_read.set_defaults(func=self.spd_read)

        parser_write = subparsers.add_parser('write')
        parser_write.add_argument('dev', type=str, help="Device Address")
        parser_write.add_argument('off', type=lambda x: int(x, 16), help="Offset (hex)")
        parser_write.add_argument('val', type=lambda x: int(x, 16), help="Byte Value (hex)")
        parser_write.set_defaults(func=self.spd_write)

        parser.parse_args(self.argv[2:], namespace=self)
        return True


    def spd_detect(self):
        self.logger.log( "[CHIPSEC] Searching for DIMMs with SPD..." )
        _dimms = self._spd.detect()
        if _dimms is not None:
            self.logger.log( "Detected the following SPD devices:" )
            for _dimm in _dimms: self.logger.log( "{}: 0x{:02X}".format(spd.SPD_DIMMS[_dimm], _dimm) )
        else:
            self.logger.log( "Unable to detect SPD devices." )


    def spd_dump(self):
        if self.dev is not None:
            _dev = self.dev.upper()
            self.dev_addr = spd.SPD_DIMM_ADDRESSES[ _dev ] if _dev in spd.SPD_DIMM_ADDRESSES else int(self.dev, 16)
            if not self._spd.isSPDPresent( self.dev_addr ):
                self.logger.log( "[CHIPSEC] SPD for DIMM 0x{:X} is not found".format(self.dev_addr) )
                return
            self._spd.decode( self.dev_addr )
        else:
            _dimms = self._spd.detect()
            for _dimm in _dimms: self._spd.decode( _dimm )


    def spd_read(self):
        _dev = self.dev.upper()
        self.dev_addr = spd.SPD_DIMM_ADDRESSES[ _dev ] if _dev in spd.SPD_DIMM_ADDRESSES else int(self.dev, 16)
        if not self._spd.isSPDPresent( self.dev_addr ):
            self.logger.log( "[CHIPSEC] SPD for DIMM 0x{:X} is not found".format(self.dev_addr) )
            return

        val = self._spd.read_byte( self.off, self.dev_addr )
        self.logger.log( "[CHIPSEC] SPD read: offset 0x{:X} = 0x{:X}".format(self.off, val) )


    def spd_write(self):
        _dev = self.dev.upper()
        self.dev_addr = spd.SPD_DIMM_ADDRESSES[ _dev ] if _dev in spd.SPD_DIMM_ADDRESSES else int(self.dev, 16)
        if not self._spd.isSPDPresent( self.dev_addr ):
            self.logger.log( "[CHIPSEC] SPD for DIMM 0x{:X} is not found".format(self.dev_addr) )
            return

        self.logger.log( "[CHIPSEC] SPD write: offset 0x{:X} = 0x{:X}".format(self.off, self.val) )
        self._spd.write_byte( self.off, self.val, self.dev_addr )


    def run(self):
        try:
            _smbus    = smbus.SMBus( self.cs )
            self._spd = spd.SPD( _smbus )
        except BaseException as msg:
            self.logger.error(msg)
            return

        t = time.time()

        if not _smbus.is_SMBus_supported():
            self.logger.log( "[CHIPSEC] SMBus controller is not supported" )
            return

        self.dev_addr = spd.SPD_SMBUS_ADDRESS
        self.func()

        self.logger.log( "[CHIPSEC] (spd) time elapsed {:.3f}".format(time.time() -t) )

commands = { 'spd': SPDCommand }
