src/dev/arm/FlashDevice.py

   1 # Copyright (c) 2013-2015 ARM Limited
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  36 # Authors: Rene de Jong
  37 #
  38
  39 from m5.params import *
  40 from m5.proxy import *
  41 from AbstractNVM import *
  42
  43 #Distribution of the data.
  44 #sequential: sequential (address n+1 is likely to be on the same plane as n)
  45 #Random: @TODO Not yet implemented
  46 #stripe: striping over all the planes
  47 class DataDistribution(Enum): vals = ['sequential', 'stripe']
  48
  49 class FlashDevice(AbstractNVM):
  50     type = 'FlashDevice'
  51     cxx_header = "dev/arm/flash_device.hh"
  52     # default blocksize is 128 kB.This seems to be the most common size in
  53     # mobile devices (not the image blocksize)
  54     blk_size = Param.MemorySize("128kB", "Size of one disk block")
  55     # disk page size is 2 kB. This is the most commonly used page size in
  56     # flash devices
  57     page_size = Param.MemorySize("2kB", "Size of one disk page")
  58     # There are many GC flavours. It is impossible to cover them all; this
  59     # parameter enables the approximation of different GC algorithms
  60     GC_active = Param.Percent(50, "Percentage of the time (in whole numbers) \
  61         that the GC is activated if a block is full")
  62     # Access latencies. Different devices will have different latencies, but
  63     # the latencies will be around the default values.
  64     read_lat = Param.Latency("25us", "Read Latency")
  65     write_lat = Param.Latency("200us", "Write Latency")
  66     erase_lat = Param.Latency("1500us", "Erase Delay")
  67     # Number of planes ought to be a power of two according to ONFI standard
  68     num_planes = Param.UInt32(1, "Number of planes per die")
  69     # Data distribution. Default is none. It is adviced to switch to stripe
  70     # when more than one plane is used.
  71     data_distribution = Param.DataDistribution('sequential', "Distribution \
  72         of the data in the adress table; Stripe needed for multiple\
  73         planes; otherwise use: sequential")
  74