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| -rwxr-xr-x | util/cbmem/cbmem.py | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/util/cbmem/cbmem.py b/util/cbmem/cbmem.py new file mode 100755 index 0000000000..3e8476dbec --- /dev/null +++ b/util/cbmem/cbmem.py @@ -0,0 +1,204 @@ +#!/usr/bin/python +# +# cbmem.py - Linux space CBMEM contents parser +# +# Copyright (C) 2011 The ChromiumOS Authors. All rights reserved. +# +# 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 of the License +# +# 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 St, Fifth Floor, Boston, MA 02110-1301 USA +# +''' +Parse and display CBMEM contents. + +This module is meant to run on systems with coreboot based firmware. + +When started, it determines the amount of DRAM installed on the system, and +then scans the top area of DRAM (right above the available memory size) +looking for the CBMEM base signature at locations aligned at 0x20000 +boundaries. + +Once it finds the CBMEM signature, the utility parses the contents, reporting +the section IDs/sizes and also reporting the contents of the tiemstamp and +console sections. +''' + +import mmap +import re +import struct +import sys +import time + +# These definitions follow src/include/cbmem.h +CBMEM_MAGIC = 0x434f5245 +CBMEM_MAX_ENTRIES = 16 + +CBMEM_ENTRY_FORMAT = '@LLQQ' +CONSOLE_HEADER_FORMAT = '@LL' +TIMESTAMP_HEADER_FORMAT = '@QLL' +TIMESTAMP_ENTRY_FORMAT = '@LQ' + +mf_fileno = 0 # File number of the file providing access to memory. + +def align_up(base, alignment): + '''Increment to the alignment boundary. + + Return the next integer larger than 'base' and divisible by 'alignment'. + ''' + + return base + alignment - base % alignment + +def normalize_timer(value, freq): + '''Convert timer reading into microseconds. + + Get the free running clock counter value, divide it by the clock frequency + and multiply by 1 million to get reading in microseconds. + + Then convert the value into an ASCII string with groups of three digits + separated by commas. + + Inputs: + value: int, the clock reading + freq: float, the clock frequency + + Returns: + A string presenting 'value' in microseconds. + ''' + + result = [] + value = int(value * 1000000.0 / freq) + svalue = '%d' % value + vlength = len(svalue) + remainder = vlength % 3 + if remainder: + result.append(svalue[0:remainder]) + while remainder < vlength: + result.append(svalue[remainder:remainder+3]) + remainder = remainder + 3 + return ','.join(result) + +def get_cpu_freq(): + '''Retrieve CPU frequency from sysfs. + + Use /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq as the source. + ''' + freq_str = open('/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq' + ).read() + # Convert reading into Hertz + return float(freq_str) * 1000.0 + +def get_mem_size(): + '''Retrieve amount of memory available to the CPU from /proc/meminfo.''' + mult = { + 'kB': 1024 + } + meminfo = open('/proc/meminfo').read() + m = re.search('MemTotal:.*\n', meminfo) + mem_string = re.search('MemTotal:.*\n', meminfo).group(0) + (_, size, mult_name) = mem_string.split() + return int(size) * mult[mult_name] + +def parse_mem_at(addr, format): + '''Read and parse a memory location. + + This function reads memory at the passed in address, parses it according + to the passed in format specification and returns a list of values. + + The first value in the list is the size of data matching the format + expression, and the rest of the elements of the list are the actual values + retrieved using the format. + ''' + + size = struct.calcsize(format) + delta = addr % 4096 # mmap requires the offset to be page size aligned. + mm = mmap.mmap(mf_fileno, size + delta, + mmap.MAP_PRIVATE, offset=(addr - delta)) + buf = mm.read(size + delta) + mm.close() + rv = [size,] + list(struct.unpack(format, buf[delta:size + delta + 1])) + return rv + +def dprint(text): + '''Debug print function. + + Edit it to get the debug output. + ''' + + if False: + print text + +def process_timers(base): + '''Scan the array of timestamps found in CBMEM at address base. + + For each timestamp print the timer ID and the value in microseconds. + ''' + + (step, base_time, max_entr, entr) = parse_mem_at( + base, TIMESTAMP_HEADER_FORMAT) + + print('\ntime base %d, total entries %d' % (base_time, entr)) + clock_freq = get_cpu_freq() + base = base + step + for i in range(entr): + (step, timer_id, timer_value) = parse_mem_at( + base, TIMESTAMP_ENTRY_FORMAT) + print '%d:%s ' % (timer_id, normalize_timer(timer_value, clock_freq)), + base = base + step + print + +def process_console(base): + '''Dump the console log buffer contents found at address base.''' + + (step, size, cursor) = parse_mem_at(base, CONSOLE_HEADER_FORMAT) + print 'cursor at %d\n' % cursor + + cons_string_format = '%ds' % min(cursor, size) + (_, cons_text) = parse_mem_at(base + step, cons_string_format) + print cons_text + print '\n' + +mem_alignment = 1024 * 1024 * 1024 # 1 GBytes +table_alignment = 128 * 1024 + +mem_size = get_mem_size() + +# start at memory address aligned at 128K. +offset = align_up(mem_size, table_alignment) + +dprint('mem_size %x offset %x' %(mem_size, offset)) +mf = open("/dev/mem") +mf_fileno = mf.fileno() + +while offset % mem_alignment: # do not cross the 1G boundary while searching + (step, magic, mid, base, size) = parse_mem_at(offset, CBMEM_ENTRY_FORMAT) + if magic == CBMEM_MAGIC: + offset = offset + step + break + offset += table_alignment +else: + print 'Did not find the CBMEM' + sys.exit(0) + +for i in (range(1, CBMEM_MAX_ENTRIES)): + (_, magic, mid, base, size) = parse_mem_at(offset, CBMEM_ENTRY_FORMAT) + if mid == 0: + break + + print '%x, %x, %x' % (mid, base, size) + if mid == 0x54494d45: + process_timers(base) + if mid == 0x434f4e53: + process_console(base) + + offset = offset + step + +mf.close() |