Nitish Sharma wrote:
> Hi PyPpl,
> For my current project I have a kernel device driver and a user-space
> application. This user-space application is already provided to me, and
> written in python. I have to extend this application with some addition
> features, which involves communicating with kernel device driver through
> ioctl() interface.
> I am fairly new with Python and not able to grok how to provide "op" in
> ioctl syntax - fcntl.ioctl (fd, op[, arg[, mutate_flag]]). Operations
> supported by device driver, through ioctl, are of the form: IOCTL_SET_MSG
> _IOR(MAGIC_NUMBER, 0, char*).
> It'd be great if some help can be provided about how to "encode" these
> operations in python to implement the desired functionality.
>
> Regards
> Nitish
Here's some of my stuff. Specific to my device, but maybe you get some ideas
-------- eioctl.py ----
from ctypes import *
libc = CDLL ('/lib/libc.so.6')
#print libc.ioctl
def set_ioctl_argtype (arg_type):
libc.ioctl.argtypes = (c_int, c_int, arg_type)
IOC_WRITE = 0x1
_IOC_NRBITS= 8
_IOC_TYPEBITS= 8
_IOC_SIZEBITS= 14
_IOC_DIRBITS= 2
_IOC_NRSHIFT= 0
_IOC_TYPESHIFT= (_IOC_NRSHIFT+_IOC_NRBITS)
_IOC_SIZESHIFT= (_IOC_TYPESHIFT+_IOC_TYPEBITS)
_IOC_DIRSHIFT= (_IOC_SIZESHIFT+_IOC_SIZEBITS)
def IOC (dir, type, nr, size):
return (((dir) << _IOC_DIRSHIFT) | \
((type) << _IOC_TYPESHIFT) | \
((nr) << _IOC_NRSHIFT) | \
((size) << _IOC_SIZESHIFT))
def ioctl (fd, request, args):
return libc.ioctl (fd, request, args)
--------------
example of usage:
# Enable byte swap in driver
from eioctl import IOC, IOC_WRITE
EOS_IOC_MAGIC = 0xF4
request = IOC(IOC_WRITE, EOS_IOC_MAGIC, 1, struct.calcsize ('i'))
err = fcntl.ioctl(eos_fd, request, 1)
--
http://mail.python.org/mailman/listinfo/python-list
