The in-kernel documentation of the bcm43xx driver is out of date. Signed-off-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx> --- Index: wireless-2.6/Documentation/networking/bcm43xx.txt =================================================================== --- wireless-2.6.orig/Documentation/networking/bcm43xx.txt +++ wireless-2.6/Documentation/networking/bcm43xx.txt @@ -2,35 +2,80 @@ BCM43xx Linux Driver Project ============================ -About this software -------------------- - -The goal of this project is to develop a linux driver for Broadcom -BCM43xx chips, based on the specification at -http://bcm-specs.sipsolutions.net/ - -The project page is http://bcm43xx.berlios.de/ - - -Requirements +Introduction ------------ -1) Linux Kernel 2.6.16 or later - http://www.kernel.org/ - - You may want to configure your kernel with: - - CONFIG_DEBUG_FS (optional): - -> Kernel hacking - -> Debug Filesystem - -2) SoftMAC IEEE 802.11 Networking Stack extension and patched ieee80211 - modules: - http://softmac.sipsolutions.net/ - -3) Firmware Files - - Please try fwcutter. Fwcutter can extract the firmware from various - binary driver files. It supports driver files from Windows, MacOS and - Linux. You can get fwcutter from http://bcm43xx.berlios.de/. - Also, fwcutter comes with a README file for further instructions. +Many of the wireless devices found in modern notebook computers are based +on the wireless chips produced by Broadcom. These devices have been a problem +for Linux users as there is no open-source driver available. In addition, +Broadcom has not released specifications for the device, and driver availability +has been limited to the binary-only form used in the GPL versions of AP +hardware such as the Linksys WRT54G, and the Windows and OS X drivers. +Before this project began, the only way to use these devices were to use the +Windows or OS X drivers with either the Linuxant or ndiswrapper modules. There +is a strong penalty if this method is used as loading the binary-only module +"taints" the kernel, and no kernel developer will help diagnose any kernel +problems. + +Development +----------- + +This driver has been developed using a clean-room technique that is described +at http://bcm-specs.sipsolutions.net/ReverseEngineeringProcess. For legal +reasons, none of the clean-room crew works on the on the Linux driver, and +none of the Linux developers sees anything but the specifications, which are +the ultimate product of the reverse-engineering group. + +Software +-------- + +Since the release of the 2.6.17 kernel, the bcm43xx driver has been distributed +with the kernel source, and is prebuilt in most, if not all, distributions. +There is, however, additional software that is required. The firmware used by the +chip is the intellectual property of Broadcom and they have not given the bcm43xx +team redistribution rights to this firmware. Since we cannot legally redistribute +the firwmare we cannot include it with the driver. Furthermore, it cannot be placed +in the downloadable archives of any distributing organization; therefore, the user is +responsible for obtaining the firmware and placing it in the appropriate location +so that the driver can find it when initializing. + +To help with this process, the bcm43xx developers provide a separate program +named bcm43xx-fwcutter to "cut" the firmware out of a Windows or OS X driver +and write the extracted files to the proper location. This program is usually +provided with the distribution; however, it may be downloaded from + +http://developer.berlios.de/project/showfiles.php?group_id=4547 + +The firmware is available in two versions. V3 firmware is used with the +in-kernel bcm43xx driver that uses a software MAC layer called SoftMAC, and +will have a microcode revision of 0x127 or smaller. The V4 firmware is used +by an out-of-kernel driver employing a variation of the Devicescape MAC layer +known as d80211. Once bcm43xx-d80211 reaches a satisfactory level of +development, it will replace bcm43xx-softmac in the kernel as it is much more +flexible and powerful. + +A source for the latest V3 firmware is + +http://downloads.openwrt.org/sources/wl_apsta-3.130.20.0.o + +Once this file is downloaded, the command 'bcm43xx-fwcutter -w <dir> <filename>' +will extract the microcode and write it to directory <dir>. The correct +directory will depend on your distribution; however, most use '/lib/firmware'. +Once this step is completed, the bcm3xx driver should load when the system is +booted. To see any messages relating to the driver, issue the command +'dmesg | grep bcm43xx' from a terminal window. If there are any problems, +please send that output to Bcm43xx-dev@xxxxxxxxxxxxxxxxx + +Although the driver has been in-kernel since 2.6.17, the earliest version is +quite limited in its capability. Patches that include all features of later +versions are available for the stable kernel versions from 2.6.18. These will +be needed if you use a BCM4318, or a PCI Express version (BCM4311 and BCM4312). +In addition, if you have an early BCM4306 and more than 1 GB RAM, your kernel +will need to be patched. These patches, which are being updated regularly, are +available at ftp://lwfinger.dynalias.org/patches. Look for +'combined_2.6.YY.patch'. Of course you will need kernel source downloaded from +kernel.org, or the source from your distribution. + +If you build your own kernel, please enable CONFIG_BCM43XX_DEBUG and +CONFIG_IEEE80211_SOFTMAC_DEBUG. The log information provided is essential for +solving any problems. - To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
