hey, I'm looking to bridge a WRT54G wireless router with the Westell
427V DSL wireless modem.
I think the Linksys should get set as a Client Bridge.
The question is, Do I need satori or alchemy firmware or DD-WRT, or
can this be done manually?
I attended the router firmware extraction / reversal seminar last week
and this seems like something hive13 is already familiar with.
Thanks, Adrian
Well, now I see OpenWrt as an option:
The standard Linksys firmware on the WRT54GS only allows the wireless
portion of the device to be used in access point mode, not in client
or bridge mode. In other words, wireless clients can connect to the
device and access its built-in switch and router, but the device
cannot connect to other wireless routers and other wireless routers
cannot connect to the device. With the OpenWrt firmware, one assumes
total control over the wireless portion of the device, so it is
possible to use it in access point, client, or bridge mode. This is
very convenient since devices that are sold as "wireless bridges" tend
to be on the expensive side.
Probably best to do this from a Ubuntu client with nvram?
adrian
flashing a WRT54GS just requires you to load the .bin file you want
via the linksys firmware loader on the router's web interface. you
can do it with any browser. just be sure to select the correct file
otherwise you will unlock the flashing red light feature 
to simplify config you will probably want an openWRT build with xWRT
rolled in. xWRT is the web interface for openWRT and makes
configuration a lot simpler. openWRT by itself is strictly command
line, which is great when you want granular control over the device,
but pretty cumbersome when you are new to the project, or you want to
try a bunch of different configs.
with that said, wireless ethernet bridging is pretty flaky, even with
the expensive gear built specifically for that purpose. it's been my
experience that unless you are getting your wifi from the kindness of
strangers, you are almost always better off fishing a cable
I’ve had decent success (defined as “never had to think about it again”) using an Asus G router with DD-WRT setup as a wireless client bridge. I use it to get a TiVo (with wired network interface only) onto my wireless network. I’d share specific settings, but that router is 120 miles away right now. I used the dd-wrt wiki page to help me set it up http://www.dd-wrt.com/wiki/index.php/Client_Bridged . And as an FYI, my host is a stock Buffalo G router, so nothing special is needed on the host side.
Client bridge was flaky as hell with a buffalo wgr300 ish thing and ddwrt. I set it up in client mode and it works flawlessly. Used guide on ddwrt wiki. Client wired network has a different subnet. I used NAT because I’m lazy but you can turn off NAT and run routing only as long as you advertise the route on the native network andor on you border gateways.
Db