Source code for spinnman.messages.scp.impl.sdram_alloc

# Copyright (c) 2017-2019 The University of Manchester
#
# 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, either version 3 of the License, or
# (at your option) any later version.
#
# 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, see <http://www.gnu.org/licenses/>.

import struct
from spinn_utilities.overrides import overrides
from spinnman.messages.scp import SCPRequestHeader
from spinnman.messages.scp.abstract_messages import (
    AbstractSCPRequest, AbstractSCPResponse)
from spinnman.messages.scp.enums import AllocFree, SCPCommand, SCPResult
from spinnman.messages.sdp import SDPFlag, SDPHeader
from spinnman.exceptions import (
    SpinnmanUnexpectedResponseCodeException, SpinnmanInvalidParameterException)

_ONE_WORD = struct.Struct("<I")


[docs]class SDRAMAlloc(AbstractSCPRequest): """ An SCP Request to allocate space in the SDRAM space """ __slots__ = [ "_size"] def __init__(self, x, y, app_id, size, tag=None): """ :param int x: The x-coordinate of the chip to allocate on, between 0 and 255 :param int y: The y-coordinate of the chip to allocate on, between 0 and 255 :param int app_id: The ID of the application, between 0 and 255 :param int size: The size in bytes of memory to be allocated :param int tag: The tag for the SDRAM, a 8-bit (chip-wide) tag that can be looked up by a SpiNNaker application to discover the address of the allocated block. If `0` then no tag is applied. """ # pylint: disable=too-many-arguments if tag is None: tag = 0 elif not(0 <= tag < 256): raise SpinnmanInvalidParameterException( "tag", "The tag param needs to be between 0 and 255, or None (in " "which case 0 will be used by default)", str(tag)) super().__init__( SDPHeader( flags=SDPFlag.REPLY_EXPECTED, destination_port=0, destination_cpu=0, destination_chip_x=x, destination_chip_y=y), SCPRequestHeader(command=SCPCommand.CMD_ALLOC), argument_1=( (app_id << 8) | AllocFree.ALLOC_SDRAM.value), # @UndefinedVariable argument_2=size, argument_3=tag) self._size = size
[docs] @overrides(AbstractSCPRequest.get_scp_response) def get_scp_response(self): return _SCPSDRAMAllocResponse(self._size)
class _SCPSDRAMAllocResponse(AbstractSCPResponse): """ An SCP response to a request to allocate space in SDRAM """ __slots__ = [ "_base_address", "_size"] def __init__(self, size): super().__init__() self._size = size self._base_address = None @overrides(AbstractSCPResponse.read_data_bytestring) def read_data_bytestring(self, data, offset): result = self.scp_response_header.result if result != SCPResult.RC_OK: raise SpinnmanUnexpectedResponseCodeException( "SDRAM Allocation", "CMD_ALLOC", result.name) self._base_address = _ONE_WORD.unpack_from(data, offset)[0] # check that the base address is not null (0 in python case) as # this reflects a issue in the command on SpiNNaker side if self._base_address == 0: raise SpinnmanInvalidParameterException( "SDRAM Allocation response base address", self._base_address, "Could not allocate {} bytes of SDRAM".format(self._size)) @property def base_address(self): """ The base address allocated, or 0 if none :rtype: int """ return self._base_address