Re: Testing a linksys WRT54GS.

[Lorenzo Colitti <]

Henk Uijterwaal wrote:
> I guess that the first thing one wants to do then, is to restore
> the original firmware.  This requires a copy of whatever was originally
> installed.  Is this available?  Can the user make one?  Is it
> possible to force a firmware onto the device?  If this can be done,
> then the problem is relatively easy: we distribute our firmware as is,
> with no guarantees.
All firmware releases are available, all the user needs to do is 
download them from the linksys web site. Of course, if the firmware has 
broken the device to the extent that it can't boot any more, this is not 
easy and requires special tricks.

> (2) Is it possible that a broken firmware will actually break the device.
> I have read warnings that using the wrong Xwindows driver can damage
> a graphics card but I've never seen this in practice, and to be honest,
> I always find it a bit hard to believe that software can damage hardware.
In theory, there's always the possibility that of damaging the wireless 
circuits by raising the transmit power too high and causing the device 
to overheat. However, that seems pretty unlikely to be caused by any of 
the changes we would be making.

> (3) We obviously do not plan to distribute broken firmware upgrades
> so we will extensively test them before distributing.  BUT this obviously
> requires that the Linksys we use, is identical to what the user has.
> Are all these devices identical?  Are there flavors, (i.e. if one buys
> a PC from D***, one often finds small difference between series)?
There are at four hardware versions of the WRT54GS:

http://www.linksys.com/servlet/Satellite?childpagename=US%2FLayout&packedargs=c%3DL_Content_C1%26cid%3D1115416835852&pagename=Linksys%2FCommon%2FVisitorWrapper

one of which (the v4.0) seems to have significantly different firmware. 
Linksys does distribute the source code to their firmware (including the 
firmware for the v4.0), so it would appear that a safe strategy would be 
simply to make modifications of existing firmware releases.

However, maintaining different forks for different hardware revisions 
might require a non-trivial amount of work, and there's always the 
possibility that future versions of the WRT54GS might not run linux at 
all (this seems aleady to be the case with the WRT54G v5.0).

Perhaps it would be a good tradeoff to buy a certain number of these up 
front, install the modified firmware on them, and distribute them to 
customers?


Cheers,
Lorenzo

--
lorenzo@localhost                  colitti@localhost
www.ripe.net                www.dia.uniroma3.it/~compunet
RIPE NCC        Roma Tre Computer Networks research group