This page covers the BCM47xx and BCM53xx Wireless Router/AP SoC running MIPS CPUs.

The current goal is to boot one image on all the different devices using SoC of the bcm47xx family. The main image is openwrt-brcm47xx-squashfs.trx which is in the generic image format used by the Broadcom SDK for these devices. Many vendors like Netgear and Linksys currently are using some own image formats to prevent a wrong image from being flashed to their devices, these images are containing the same code as the generic image, but do have some special header just for this device, mostly containing the internal device name and the version of this firmware.

If you want to flash OpenWrt from the default firmware use the image for your device if there is one, otherwise use openwrt-brcm47xx-squashfs.trx image. For sysupgrade always use the generic image openwrt-brcm47xx-squashfs.trx independently from what image you initially flashed to your device.

If that does not work you could download the image builder our check out OpenWrt from the svn and edit target/linux/brcm47xx/image/Makefile to fit your needs. If you have to do some modifications to generate a valid image and it boots on your device please send a patch to the mailing list for inclusion into OpenWrt.

Version 12.09-rc1: http://downloads.openwrt.org/attitude_adjustment/12.09-rc1/brcm47xx/

This image has support for all BCM47xx SoCs using SSB. These are all devices with a ieee802.11b or ieee802.11g Wifi support and the BCM4785/BCM4705 with an additional ieee80211n PCI devices connected to the SoC. This also includes some devices without any Wifi functionality using this SOC.

This SoC has a different Ethernet core and does not use b44 as the Ethernet driver but is needs tg3 for that. The default images for Attitude Adjustment do not include the tg3 Ethernet driver. Use the image builder (OpenWrt-ImageBuilder-brcm47xx-for-linux-i486.tar.bz2) to generate a image with Ethernet support. The profile with b43 as the wifi driver is name Bcm4705-b43.

make image PROFILE="Bcm4705-b43"

Snapshot images download: http://downloads.openwrt.org/snapshots/trunk/brcm47xx/

This is the current version where development takes place. It contains support for all the SoC also supported by Attitude Adjustment and in addition also some most of the recent bcm47xx SoCs. It should at least boot of all the know MIPS based BCM47xx and BCM53xx based SoCs.

The default Barrier Breaker images are containing the b44, tg3 and bgmac Ethernet driver so Ethernet should work on all supported services without using the image builder. If you want to safe some space you could use the image builder to generate a image better suiting your device.

There are different Wifi drivers for the Broadcom Wifi cores found in the SoCs or the PCI(e) or USB connected Wifi chips on the boards. There is no driver supporting all chips and all have their pros and cons. Some chips are supported by 3 of these drivers and others are supported by non of these drivers.

b43 is the Open source driver build by the community based on reverse engineered specifications of the proprietary Broadcom driver. This driver supports most on the current available Broadcom Wifi cores. It has support for station, AP, AdHoc, Mesh and other modes, but it just supports ieee80211g rates and does not support operating in the 5GHz band.

Website: http://wireless.kernel.org/en/users/Drivers/b43

This is for some very old ieee802.11b and first generation Broadcom ieee802.11g compatible devices. This driver has a similar feature set to b43 and is only supported by the community based on reverse engineered specifications.

Website: http://wireless.kernel.org/en/users/Drivers/b43

brcmsmac supports some recent soft mac ieee802.11n Broadcom wifi cores found on PCIe cards and in SoCs, for details see the website. This driver is developed and supported by Broadcom. The current version only supports station mode, but there are patches in current OpenWrt trunk which are adding support for AP and Ad Hoc mode. brcmsmac is capable of operation devices with ieee80211n rates and running the in the 5GHz band, but AP mode currently does not work in the 5GHz band.

Website: http://wireless.kernel.org/en/users/Drivers/brcm80211

brcmfmac supports some recent full mac ieee802.11n Broadcom wifi cores found on USB, SDIO and SPI interfaces, for details see the website. This driver is developed and supported by Broadcom.

Website: http://wireless.kernel.org/en/users/Drivers/brcm80211

broadcom-wl contains the proprietary closed source Broadcom driver. The closed source part was created especially for OpenWrt and is independed from the kernel version in use. This driver supports many of the ieee802.11g devices and some of the earlier ieee802.11n devices. It is capable of operating in AP mode and also supports the 5GHz band.

When using sysupgrade always use openwrt-brcm47xx-squashfs.trx and not any device specific file.

See also '.bin' to '.trx' image conversion.

Most of the recent devices have a CFE bootloader able to boot images over the network.

To build an image bootable over the network select the following: "Target Images" —> [x] "ramdisk" —> Compression —> [xz] This will generate a file in bin/brcm47xx/openwrt-brcm47xx-vmlinux.elf

The following example boots an elf image from the tftp server at 192.168.1.2 under the path /brcm47xx/openwrt-brcm47xx-vmlinux.elf:

boot -tftp -elf 192.168.1.2:/brcm47xx/openwrt-brcm47xx-vmlinux.elf

List with some detailed informations about bcm47xx SoCs: http://wireless.kernel.org/en/users/Drivers/b43/soc