On 08/28/2012 04:24 PM, Adam Barta wrote:
Could you share a code snippet?
Here's the code.
If you cat the file to hd does it read correctly even with the zero
filesize?
I'll have to make a small mod before trying that. I'll let you know.
Tom
On Wed, Aug 29, 2012 at 1:19 AM, Tom Kuiper <kui...@jpl.nasa.gov
<mailto:kui...@jpl.nasa.gov>> wrote:
On 08/28/2012 04:11 PM, Adam Barta wrote:
is it possible that ipython is not actually closing the file but
keeping the file descriptor open behind your back, if so then
seeking to 0 might solve it?
Clever idea! but, alas, Python is cleverer than that. I put a
seek(0) after (re)opening the file and before reading. Still get
0 bytes back.
I'm not having much luck in finding a way to change the file
size. There is a 'truncate' method that will do it but Linux will
zero fill an extended file.
Cheers
Tom
On Wed, Aug 29, 2012 at 1:00 AM, Tom Kuiper <kui...@jpl.nasa.gov
<mailto:kui...@jpl.nasa.gov>> wrote:
On 08/28/2012 03:54 PM, David MacMahon wrote:
On Aug 28, 2012, at 3:39 PM, Tom Kuiper wrote:
I don't know how to get Python to read more than teh
nominal file size if it is supposed to look like a file.
If you want to read the register value a second time, you
need to seek to the beginning of the file first, then
read four bytes. You should be able to repeat the
seek/read pattern as many times as you want.
I close the file after I write to it and open it again for
the read. After I write to the file, "ls -l" gives a size of
zero instead of 4.
If that's not what's confusing you, can you please
clarify what is?
I am not trying to mix reads and writes on an open file. I
know about seek and tell if that were what I wanted to do.
Tom
--
*Adam Barta*
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e: a...@ska.ac.za <mailto:a...@ska.ac.za>
w: www.ska.ac.za <http://www.ska.ac.za>
--
I or me?http://www.oxforddictionaries.com/page/145
--
*Adam Barta*
c: +27 72 105 8611
e: a...@ska.ac.za <mailto:a...@ska.ac.za>
w: www.ska.ac.za <http://www.ska.ac.za>
--
I or me? http://www.oxforddictionaries.com/page/145
# -*- coding: utf-8 -*-
from glob import glob
from os.path import basename
import shlex
from subprocess import PIPE, Popen
from struct import pack,unpack
import io
roach_file_system = "/home/kuiper/mnt/kuiper-localhost:60001/"
def roach_command(command):
prefix = "/usr/bin/ssh -p 60002 root@localhost "
try:
p = Popen(prefix+command, stdout=PIPE, shell=True)
except OSError, details:
print "Popen failed with OS error\n",details
return
try:
response = p.stdout.readlines()
return response
except Exception:
raise Exception
def get_task_details(task):
response = roach_command("ps -ef | grep "+task)
if len(response) == 1:
result = {}
items = response[0].split()
result['owner'] = items[0]
result['taskPID'] = items[1]
result['parentPID'] = items[2]
result['command'] = items[-1]
return result
else:
print "Too many lines in response"
for line in response:
print line
raise RunTimeError
def show_registers(registers):
keys = registers.keys()
keys.sort()
for register in keys:
print("%20s %5d %s" %
(register,registers[register],read_register_chars(register)))
def get_register_size(roach_register_path):
file_listing = roach_command("ls -l "+roach_register_path)
register_size = {}
for line in file_listing[1:]:
parts = line.strip().split()
name = parts[-1]
register_size[name] = int(parts[4])
return register_size
def read_register(register):
reg_fd = io.open(local_register_path+register,
mode='rb',
buffering=0)
reg_fd.seek(0)
bytes = buffer(reg_fd.read(4) )
print "read_register got %s bytes" % len(bytes)
reg_fd.close()
return bytes
def write_register(register,uint):
bytes = pack("<I",uint)
print "write_register input: %s bytes: %s" % (len(bytes),buffer(bytes))
reg_fd = io.open(local_register_path+register,
mode='wb',
buffering=0)
try:
written = reg_fd.write(buffer(bytes))
print "write_register wrote",written,"bytes"
print "file pointer is now at",reg_fd.tell()
except Exception:
raise Exception, "writing word failed"
else:
print "Closing register"
reg_fd.close()
return True
def read_register_uint(register):
bytes = read_register(register)
print "read_register_uint got %s bytes" % len(bytes),
result = unpack("<I",bytes)
return result[0]
def read_register_int(register):
bytes = read_register(register)
result = unpack("<i",bytes)
return result[0]
def read_register_chars(register):
bytes = read_register(register)
result = unpack("<4c",bytes)
return result
def read_register_bytes(register):
bytes = read_register(register)
result = unpack("<4b",bytes)
return result
def read_register_ubytes(register):
bytes = read_register(register)
result = unpack("<4B",bytes)
return result
def bit_value(register,bit):
"""
bit 0 is the least significant bit
"""
return bool(register & 2**bit)
def set_bit(register,bit):
current_value = read_register_uint(register)
print "set_bit initial register:",bin(current_value)
new_value = current_value | 2**bit
print "set_bit revised register:",bin(new_value)
if write_register(register,new_value):
return True
else:
raise RunTimeException,"setting bit failed"
def clr_bit(register,bit):
current_value = read_register_uint(register)
new_value = ~(~current_value | 2**bit)
new_value = current_value | 2**bit
if write_register(register,new_value):
return True
else:
raise RunTimeException,"clearing bit failed"
def get_bram(device):
"""
set 'trig_adc0' bit 0 to high and toggle adcsnap_ctrl bit 0.
The capture buffer is called 'adcsnap_bram'.
"""
if __name__ == "__main__":
task_details = get_task_details("dtospec")
roach_register_path = "/proc/"+task_details['taskPID']+"/hw/ioreg/"
local_register_path = roach_file_system + roach_register_path[1:]
registers = glob(local_register_path+"*")
registers.sort()
register_size = get_register_size(roach_register_path)
show_registers(register_size)
print "Board ID: ", read_register_ubytes('sys_board_id')
print "10Gbe dest'n: ", read_register_bytes('dest_ip')
print "ADC0 trigger: ", read_register_uint('trig_adc0')
print "sum sq ADC samples:", read_register_int('adc_sum_sq0')
#print read_register_uint('acc_cnt')
set_bit('sys_scratchpad',1)
print read_register_uint('sys_scratchpad')
#clr_bit('trig_adc0',0)
#print "ADC0 trigger:", read_register_uint('trig_adc0')
