blob: 05bc4021fd4ae6e86435919c49efc7a7bf35b658 [file] [log] [blame]
# Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
import logging
import os
from autotest_lib.client.bin import test, utils
from autotest_lib.client.common_lib import error
# Allowable amount of bits eMMC vendor can use in firmware to support bad block
# replacement and metadata.
# Amount of data available for user data in device, the rest is left for
# over provisioning.
# Typically a SATA device will use 7% over provisioning [the difference
# between GB and GiB], but some eMMC device can use 9%.
# With Flash becoming more error prone as lithography shrinks, the trend
# is to increase over provisioning.
class hardware_DiskSize(test.test):
Check that disk size is around 16GB at least.
version = 1
def _is_emmc(self):
path = os.path.join("/sys/class/block/", self._device,
"device", "type")
if not os.path.exists(path):
return False
return utils.read_one_line(path) == 'MMC'
def _gib_to_gb(cls, gib):
return float(gib) * (1 << 30) / (10 ** 9)
def _compute_min_gb(self):
"""Computes minimum size allowed primary storage device.
TODO(tbroch): Add computation of raw bytes in eMMC using 'Chip Specific
Data' (CSD & EXT_CSD) defined by JEDEC JESD84-A44.pdf if possible.
CSD :: /sys/class/block/<device>/device/csd
EXT_CSD :: debugfs
Algorithm should look something like this:
CSD[C_SIZE] = 0xfff == eMMC > 2GB
EXT_CSD[SEC_COUNT] = # of 512byte sectors
Now for existing eMMC I've examined I do see the C_SIZE == 0xfff.
Unfortunately the SEC_COUNT appears to have excluded the sectors
reserved for metadata & repair. Perhaps thats by design in which case
there is no mechanism to determine the actual raw sectors.
For now I use 0.25GB as an acceptable fudge.
integer, in GB of minimum storage size.
if self._is_emmc():
return self._gib_to_gb(min_gb)
def run_once(self):
root_dev = utils.get_root_device()
self._device = os.path.basename(root_dev)
disk_size = utils.get_disk_size(root_dev)
if not disk_size:
raise error.TestError('Unable to determine main disk size')
# Capacity of a hard disk is quoted with SI prefixes, incrementing by
# powers of 1000, instead of powers of 1024.
gb = float(disk_size) / (10 ** 9)
self.write_perf_keyval({"gb_main_disk_size": gb})
min_gb = self._compute_min_gb()"DiskSize: %.3f GB MinDiskSize: %.3f GB", gb, min_gb)
if (gb < min_gb):
raise error.TestError("DiskSize %.3f GB below minimum (%.3f GB)" \
% (gb, min_gb))