WirelessNetworking

It appears that simple and affordable wireless networking may now be possible with the AVR32 and other embedded Linux systems, without signing a non-disclosure agreement, or waiting while the sales and support people ignore you (unless you are a Tier 1 customer). The latest release candidate of the Linux kernel (2.6.24-rc3 at the time of this writing) contains drivers for the Marvell 88W8385 wireless chipset along with a CompactFlash, USB, and SDIO stack for it.

The following options need to be enabled in the kernel configuration:

Networking->Wireless->802.11

Device Drivers->Network Device Support->Wireless LAN->Marvell Libertas

the required kernel modules are called libertas.ko, libertas_sdio.ko, libertas_cs.ko, firmware_class.ko, ieee80211, and ieee80211_crypt.

Also required is the for the Marvell chip.

Firmware can be loaded by a simple hotplug script:

#!/bin/sh

# Simple hotplug script sample:
#
# Both $DEVPATH and $FIRMWARE are already provided in the environment.

# check /tmp/hotplug.set.xxx for script debugging purposes
set > /tmp/hotplug.set.$$

HOTPLUG_FW_DIR=/lib/firmware/

echo 1 > /sys/$DEVPATH/loading
cat $HOTPLUG_FW_DIR/$FIRMWARE > /sys/$DEVPATH/data
echo 0 > /sys/$DEVPATH/loading

# To cancel the load in case of error:
#
#       echo -1 > /sys/$DEVPATH/loading
#
-----------------------------

Just save the script above as /sbin/fwloader and enable it like this:

echo /sbin/fwloader > /proc/sys/kernel/hotplug

Wireless Chipset Module:

Gumstix's Marvell 88W8385 based WiFi module. It's a real deal at $40.00 + shipping. It also comes with an antenna. It is manufactured by Wistron NeWeb^? Corporation, and is called the . Here is the datasheet. It is not possible to use the SPI or SDIO interface with the Gumstix module because the SDIO_D0 and SPI_CS are not available on the connector. Here is another possible source of WiFi^? modules.

The 88W8385 chip supports compact flash, SPI, and SDIO interfacing. Here's another for another similar module using the 88W8385.

* Gumstix module pin arrangement and compact flash connections:

Eagle from gumstix

Connectors:

The mating 50 position Molex connector 54722-0507-C and it's

For prototyping, an SMD to through hole prototyping adapter will also be helpful.

Firmware

Apparently the story goes like this, Marvell licensed the firmware from a third party for this chip, so they don't own it. Since they don't own it they can't or won't redistribute it. But somehow the folks at gumstix have a copy to use with their products. Anyway, the links below contain what I have found. This firmware may or may not work. I hope to test it within a week or so, when my prototyping board is delivered.

* sd8385_firmware.tar.bz2: Firmware for cf8385_B0/W8015

* sd8385_firmware2.tar.bz2: Another possible firmware set

* extract_fw.c: Simple C program to extract firmware from source code

* WLAN_Firmware_Spec_v5_1.pdf: SD8385 firmware specs

* DRCM-81_g_eModule_1.0_0324.pdf: Wistron DRCM81 Wifi module datasheet