BSD Kernel Interfaces Manual
cmx — Omnikey CardMan 4040 smartcard reader device driver
The cmx driver provides support for the PCCARD based Omnikey CardMan 4040 smartcard reader. The
driver provides a character device special file based Chip/Smart Card Interface Devices (CCID) interface.
The driver implements what the vendor calls the Synchronious API onto the smartcard reader device.
Reading and writing is synchronious, meaning that a call to write(2) directly corresponds to a complete
CCID command sent to the device, while the following read(2) will return the complete answer from the
reader. There is no support for partial reads or writes. There is no upper limit on CCID request or response
sizes, but the complete CCID request must be sent to the driver in write(2) and the complete CCID
response must fit into the buffer supplied to read(2).
Non-blocking I/O, select(2) and poll(2) are supported and work as expected. An open file descriptor
will always be ready for writing, but only ready for reading if the device indicates that it has data available.
Userland smartcard code written for the vendor’s Linux drivers should work with the cmx driver without
Character device special file.
/usr/ports/security/openct OpenCT, a userspace smartcard daemon containing a CCID driver
which directly supports cmx devices.
The cmx driver first appeared in FreeBSD 7.1.
The cmx driver was written by Daniel Roethlisberger 〈firstname.lastname@example.org〉 , originally based on the Linux driver
v1.1.0 by Omnikey GmbH
〈www.omnikey.com〉 . Early testing and bug fixes by Marcin Cieslak
The way the cmx driver talks to the CardMan 4040 is a bit rough. Due to the complete lack of hardware
documentation other than vendor drivers for other operating systems, the gory details of the device’s I/O reg-
isters are not understood very well. There may be error conditions which can only be solved by physically