b43legacy is a driver for 802.11b devices from Broadcom (BCM4301 and BCM4303) and early model 802.11g chips (BCM4306 Ver. 2) used in the Linksys WPC54G V1 PCMCIA devices. Newer 802.11g and 802.11a devices need b43. 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 V3 firmware, which must be installed separately using b43-fwcutter. This driver can be built as a module (recommended) that will be called "b43legacy". If unsure, say M.
Say Y, because this information will help you get the driver running. This option generates a minimum of log output.
Include both, Direct Memory Access (DMA) and Programmed I/O (PIO) data transfer modes. The mode actually used is selectable through the module parameter "pio". With pio=0 as a module parameter, the default DMA is used, otherwise PIO is used. If unsure, choose this option.
Only include Direct Memory Access (DMA). This reduces the size of the driver module, by omitting the PIO code.
Only include Programmed I/O (PIO). This reduces the size of the driver module, by omitting the DMA code. Please note that PIO transfers are slow (compared to DMA). Also note that not all devices of the b43legacy series support PIO. You should use PIO only if DMA does not work for you.