I successfully replaced the 16 megabyte chip with this 64 megabyte chip on my WRT54GL 1.1. The router booted right up the first time and I was able to see the expected 32 megabytes of space. However, once I attempted to change what appears to be the way the BCM5352 addresses memory as outlined on this link in order to access the full 64 megabytes

http://wiki.openwrt.org/OpenWrtDocs/Cus … AM_upgrade

then it bricked. The power LED flashes quickly and the ethernet LED's are stuck on all the time. I tried all of the easy stuff (like TFTP) to get it back, but I can't connect over ethernet no matter what I do on the PC. It just keeps saying "network cable unplugged" regardless of what I do on the PC side. I then worked my way through this guide

http://dd-wrt.com/wiki/index.php/Index: … _router.21

and eventually built an unbuffered JTAG cable as defined here

http://wiki.openwrt.org/OpenWrtDocs/Cus … JTAG_Cable

I was able to connect over JTAG, but whenever I try to probe or do anything the HairyDairyMaid utility gets stuck at "Enabling Memory Writes ..." and won't continue. The first thing I tried was using the "/noemw" command and I attempted to erase the NVRAM. No effect. I then attempted to erase and reflash the CFE with a CFE generated by the SkyNet repair kit. The flash took a few minutes, but there was still no change in the status of the router. When the "/noemw" is used, does this prevent erasing or overwriting?

I refuse to believe that what appears to be a "simple" memory addressing error bricks the whole thing. There has go to be a way to get this thing back. For the record, at this point something tells me it doesn't really matter, but I was using the "standard generic" DD-WRT v24 firmware located here

I have also read through the entire 4-page thread listed above concerning the 64 megabyte upgrade, but I couldn't find anything that specifically addresses my issue.

Thanks in advance for any help.

thecross,
  I now have two wrt54GLs that are in the same boat.  Both went fine, run for awhile, when I did nvram set sdram_init=0x0113 and comminted both have never rebooted from that.
I have used the JTAG to erase the nvram and that does not fix it.  I have reuploaded the CFE that was taken from a backup before the upgrade, and that has not fixed it.  There must be something that the HailryDairyMaid tools is not erasing when we do this.   When I backedup the wholerom the file was only 2 Megs not the 4 I expected.  I wonder if the addresses in the program are not right for the GL.

  Please let me know if you find a way out of this.  I would like to clean these two.

- M

Have a look at this thread for possibly useful information:
http://forum.openwrt.org/viewtopic.php?id=14560

I have now fixed both of these.   Both wrt54g.exe and tjtag.exe don't set the length of the flash correctly so the -erase:nvram command does not clear the nvram.  I used -erase:custom and set the start and length manualy for a 4 M flash and it got the CFE running again.

After that I found that if I only used sdram_init = 0x0113 and did not change  sdram_ndcl that it gives me all 64Megs of ram and does not lockup.  If I set sdram_ndcl to zero it does not boot and I have to erase the nvram again.

Never trust any Wiki. And second it's your own fault if you brick your router by doing such difficult and dangerous modifications on your hardware.

You are on your own...

(Last edited by forum2008 on 3 Mar 2008, 18:23)