Host AP driver for Intersil Prism2/2.5/3


Host AP is a Linux driver for wireless LAN cards based on Intersil's Prism2/2.5/3 chipset. The driver supports a so called Host AP mode, i.e., it takes care of IEEE 802.11 management functions in the host computer and acts as an access point. This does not require any special firmware for the wireless LAN card. In addition to this, it has support for normal station operations in BSS and possible also in IBSS. WPA and RSN (WPA2) is supported when used with accompanied tools, wpa_supplicant (WPA/RSN Supplicant) and hostapd (WPA/RSN Authenticator). All these programs have been designed for both desktop/laptop computers and embedded systems.

Intersil's station firmware for Prism2 chipset supports a so called Host AP mode in which the firmware takes care of time critical tasks like beacon sending and frame acknowledging, but leaves other management tasks to host computer driver. This driver implements basic functionality needed to initialize and configure Prism2-based cards, to send and receive frames, and to gather statistics. In addition, it includes an implementation of following IEEE 802.11 functions: authentication (and deauthentication), association (reassociation, and disassociation), data transmission between two wireless stations, power saving (PS) mode signaling and frame buffering for PS stations. The driver has also various features for development debugging and for researching IEEE 802.11 environments like access to hardware configuration records, I/O registers, and frames with 802.11 headers.

When used with a user space daemon, the combination of the Host AP driver and hostapd daemon includes additional features. These include support for IEEE 802.1X and dynamic WEP rekeying, RADIUS Accounting, RADIUS-based ACL for IEEE 802.11 authentication, minimal IAPP (IEEE 802.11f), WPA, IEEE 802.11i/RSN/WPA2.

Linux Wireless LAN Howto has some useful information about wireless LAN support in Linux. In addition, it includes information about which cards are Prism2-based (and can thus be used in Host AP mode).


Host AP driver
Copyright (c) 2001-2002, SSH Communications Security Corp and Jouni Malinen.
Copyright (c) 2002-2007, Jouni Malinen and contributors.
Author: Jouni Malinen <>

Host AP utils
Copyright (c) 2002-2005, Jouni Malinen <> and contributors.

Note! Host AP driver was added into the main kernel tree in Linux v2.6.14. The version in the kernel tree should be used instead of this external hostap-driver package. The external releases are only for older kernel versions and all the future development will be in the main kernel tree.

Wireless Tools for Linux

Please, note that you will need quite recent version of Wireless Tools to use some features of the Host AP driver. Using the latest version of the tools is recommended. Some features might also require latest beta version.

Jouni Malinen
Last modified: Sat Jan 12 13:27:18 EET 2013