a6be3fd503
We currently use the traditional SI-like prefixes to represent binary multipliers in some contexts. This is ambiguous in many cases since they overload the meaning of the SI prefix. Here are some examples of commonly used in the industry: * Storage vendors define 1 MB as 10**6 bytes * Memory vendors define 1 MB as 2**20 bytes * Network equipment treats 1Mbit/s as 10**6 bits/s * Memory vendors define 1Mbit as 2**20 bits In practice, this means that a FLASH chip on a storage bus uses decimal prefixes, but that same flash chip on a memory bus uses binary prefixes. It would also be reasonable to assume that the contents of a 1Mbit FLASH chip would take 0.1s to transfer over a 10Mbit Ethernet link. That's however not the case due to different meanings of the prefix. The quantity 2MX is treated differently by gem5 depending on the unit X: * Physical quantities (s, Hz, V, A, J, K, C, F) use decimal prefixes. * Interconnect and NoC bandwidths (B/s) use binary prefixes. * Network bandwidths (bps) use decimal prefixes. * Memory sizes and storage sizes (B) use binary prefixes. Mitigate this ambiguity by consistently using the ISO/IEC/SI prefixes for binary multipliers for parameters and comments where appropriate. Change-Id: I9b47194d26d71c8ebedda6c31a5bac54b600d3bf Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/39575 Reviewed-by: Richard Cooper <richard.cooper@arm.com> Tested-by: kokoro <noreply+kokoro@google.com>
73 lines
3.8 KiB
Python
73 lines
3.8 KiB
Python
# Copyright (c) 2013-2015 ARM Limited
|
|
# All rights reserved.
|
|
#
|
|
# The license below extends only to copyright in the software and shall
|
|
# not be construed as granting a license to any other intellectual
|
|
# property including but not limited to intellectual property relating
|
|
# to a hardware implementation of the functionality of the software
|
|
# licensed hereunder. You may use the software subject to the license
|
|
# terms below provided that you ensure that this notice is replicated
|
|
# unmodified and in its entirety in all distributions of the software,
|
|
# modified or unmodified, in source code or in binary form.
|
|
#
|
|
# Redistribution and use in source and binary forms, with or without
|
|
# modification, are permitted provided that the following conditions are
|
|
# met: redistributions of source code must retain the above copyright
|
|
# notice, this list of conditions and the following disclaimer;
|
|
# redistributions in binary form must reproduce the above copyright
|
|
# notice, this list of conditions and the following disclaimer in the
|
|
# documentation and/or other materials provided with the distribution;
|
|
# neither the name of the copyright holders nor the names of its
|
|
# contributors may be used to endorse or promote products derived from
|
|
# this software without specific prior written permission.
|
|
#
|
|
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
from m5.params import *
|
|
from m5.proxy import *
|
|
|
|
from m5.objects.AbstractNVM import *
|
|
|
|
#Distribution of the data.
|
|
#sequential: sequential (address n+1 is likely to be on the same plane as n)
|
|
#Random: @TODO Not yet implemented
|
|
#stripe: striping over all the planes
|
|
class DataDistribution(Enum): vals = ['sequential', 'stripe']
|
|
|
|
class FlashDevice(AbstractNVM):
|
|
type = 'FlashDevice'
|
|
cxx_header = "dev/arm/flash_device.hh"
|
|
# default blocksize is 128 KiB.This seems to be the most common size in
|
|
# mobile devices (not the image blocksize)
|
|
blk_size = Param.MemorySize("128KiB", "Size of one disk block")
|
|
# disk page size is 2 KiB. This is the most commonly used page size in
|
|
# flash devices
|
|
page_size = Param.MemorySize("2KiB", "Size of one disk page")
|
|
# There are many GC flavors. It is impossible to cover them all; this
|
|
# parameter enables the approximation of different GC algorithms
|
|
GC_active = Param.Percent(50, "Percentage of the time (in whole numbers) \
|
|
that the GC is activated if a block is full")
|
|
# Access latencies. Different devices will have different latencies, but
|
|
# the latencies will be around the default values.
|
|
read_lat = Param.Latency("25us", "Read Latency")
|
|
write_lat = Param.Latency("200us", "Write Latency")
|
|
erase_lat = Param.Latency("1500us", "Erase Delay")
|
|
# Number of planes ought to be a power of two according to ONFI standard
|
|
num_planes = Param.UInt32(1, "Number of planes per die")
|
|
# Data distribution. Default is none. It is adviced to switch to stripe
|
|
# when more than one plane is used.
|
|
data_distribution = Param.DataDistribution('sequential', "Distribution \
|
|
of the data in the adress table; Stripe needed for multiple\
|
|
planes; otherwise use: sequential")
|
|
|