b43 is a driver for the Broadcom 43xx series wireless devices. Check "lspci" for something like "Broadcom Corporation BCM43XX 802.11 Wireless LAN Controller" to determine whether you own such a device. This driver supports the new BCM43xx IEEE 802.11G devices, but not the old IEEE 802.11B devices. Old devices are supported by the b43legacy driver. Note that this has nothing to do with the standard that your AccessPoint supports (A, B, G or a combination). IEEE 802.11G devices can talk to IEEE 802.11B AccessPoints. It is safe to include both b43 and b43legacy as the underlying glue layer will automatically load the correct version for your device. This driver uses V4 firmware, which must be installed separately using b43-fwcutter. This driver can be built as a module (recommended) that will be called "b43". If unsure, say M.
Broadcom 43xx PCMCIA device support. Support for 16bit PCMCIA devices. Please note that most PC-CARD devices are _NOT_ 16bit PCMCIA devices, but 32bit CardBUS devices. CardBUS devices are supported out of the box by b43. With this config option you can drive b43 cards in CompactFlash formfactor in a PCMCIA adaptor. CF b43 cards can sometimes be found in handheld PCs. It's safe to select Y here, even if you don't have a B43 PCMCIA device. If unsure, say N.
Broadcom 43xx device support for Soft-MAC SDIO devices. With this config option you can drive Soft-MAC b43 cards with a Secure Digital I/O interface. This includes the WLAN daughter card found on the Nintendo Wii video game console. Note that this does not support Broadcom 43xx Full-MAC devices. It's safe to select Y here, even if you don't have a B43 SDIO device. If unsure, say N.
Support for the N-PHY. This enables support for devices with N-PHY. Say N if you expect high stability and performance. Saying Y will not affect other devices support and may provide support for basic needs.
Support for the LP-PHY. The LP-PHY is a low-power PHY built into some notebooks and embedded devices. It supports 802.11a/g (802.11a support is optional, and currently disabled).
Broadcom 43xx debugging. This adds additional runtime sanity checks and statistics to the driver. These checks and statistics might me expensive and hurt runtime performance of your system. This also adds the b43 debugfs interface. Do not enable this, unless you are debugging the driver. Say N, if you are a distributor or user building a release kernel for production use. Only say Y, if you are debugging a problem in the b43 driver sourcecode.
This will disable DMA and always enable PIO instead. Say N! This is only for debugging the PIO engine code. You do _NOT_ want to enable this.