Mem: 6664K used, 23204K free, 0K shrd, 0K buff, 2608K cached
Load average: 0.19 0.12 0.12
  PID USER     STATUS   RSS  PPID %CPU %MEM COMMAND
  647 root     R        392   643  2.8  1.3 top
  641 root     S        560   535  0.0  1.8 dropbear
   78 root     S        484     1  0.0  1.6 ash
  643 root     S        476   641  0.0  1.5 ash
    1 root     S        396     0  0.0  1.3 init
  535 root     S        392     1  0.0  1.3 dropbear
  511 nobody   S        352     1  0.0  1.1 dnsmasq
   70 root     S        324     1  0.0  1.0 syslogd
  466 root     S        324     1  0.0  1.0 crond
   73 root     S        280     1  0.0  0.9 klogd
  488 root     S        200     1  0.0  0.6 telnetd
  482 root     S        168     1  0.0  0.5 httpd
   61 root     SWN        0     1  0.0  0.0 jffs2_gcd_mtd1
    4 root     SW<        0     1  0.0  0.0 khelper
   44 root     SW         0     1  0.0  0.0 mtdblockd
   20 root     SW<        0     5  0.0  0.0 kblockd/0
    3 root     SW<        0     1  0.0  0.0 events/0
    5 root     SW<        0     1  0.0  0.0 kthread
    2 root     SWN        0     1  0.0  0.0 ksoftirqd/0
   31 root     SW         0     5  0.0  0.0 pdflush
   32 root     SW         0     5  0.0  0.0 pdflush

Got to make some other things work but on general...working...

Just out of curiosity, how did you get the old SDRAM chip off the board? I have access to a hot air desoldering station, but there are so many passives nearby, I'm afraid to use it for fear of blowing them off the board (literally). I'll have to check and see if we have any tips that can shape the airstream, but I suspect a shield (old piece of metal?) would be best.

Also, what did you do to OpenWRT to allow it to recognize the additional memory?

I'm curious, because I want to turn my La Fonera into an embedded systems for another project. The extra RAM would be useful.

I use the chipquik removing solder stuff. You need the exact nozzle if you want to use a hot air station.

I did nothing to openwrt...everything has to be done through redboot. Took 1 week to gather all the sources, 1 whole day to get it to compile, and 1 whole day to customize it to our config.

I just got the ethernet working in redboot so time to reflash my redboot

How did you get the chip?

You can basically find this chip on PC100 or PC133 ram sticks but needs to be 256MB with only single sided, 8 chips. or 256mb on notebooks. It should be 16MB x 16 bit configuration. I gave up as I couldn't find any so I just bought two chips from www.digikey.com to try. Only $7 CDN per chip.

OK, then it looks to expensive for me... The shipping costs are high to sweden.
And i looked on every SDRAM mem i have, and nothing...

Too Bad...

Maybe i'll find something in the future...

You can always get north american friends. I AM SURE there are electronics sites in europe that sell similar chips.

Well done GoldServe...

Wouldn't it be nice to have an MMC driver kernel mod and what's the problem with it ?

I don't have experience writing kernel modules and definitely not related to the filesystem.

Just out of curiosity, what did you have to do in/to redboot to get it to recognize the extra RAM?

Well, the two sources I got did not work out of the box so it involves porting the meraki changes to the other source I got.

I would like to upgrade my two La Fonera's, but I don't want to order parts until I know what is involved with modifying redboot. Are you planning to release a patch/HOWTO?

At the moment, I have a serial port connected, so I can access the redboot prompt, but I'm still very new to all of this. I have a Xilinx JTAG programmer that could probably be fitted if necessary, but I'm hoping this is something that can be undertaken without going to that level of trouble.

Easy. I can send you the rom file and you can follow very simple instructions on updating your rom. It should be fast, just don't loose power in the 1 minute it is flashing.

@GoldServe - Could you make a 'howto' and put it in the wiki, as I and maybe others are also interested.

Ditto. A howto would be awesome.

Okay, when I got my so-dimm, I will post a complete how to to replace the ram chip.

I couldn't find any appropriate DIMM's either, so I ended up buying them on Digikey. I ended up going with the Micron MT48LC16M16A2TG-7E SDRAM. It's PC133 in 54-pin TSOP package, and were $10.13 (US) a piece. These are the exact same part as are on some of the DIMM's in my older computers.

Thankfully, there are two folks I work with who do board work, and can handle swapping the chips.

Now, I wonder if I can reuse the old chips in my WRT54G - v6? I've been told you can double the memory from 4MB to 8MB, but I'm not sure about a 16MB part.

I believe the parts in the broadcom units are DDR rams and not SDRAM.

I hope I get my so-dimms soon because I only paid $20 for 8 pieces of ram!

Apparently the Broadcom chips can use either DDR or SDR SDRAM. I looked up the SDRAM in my WRT54G v6, and it is indeed an SDR SDRAM. In fact, it is the same brand and base part number as the memory in my La Fonera - just smaller. (They both use the Hynix 57Vxx1620 SDR SDRAM)

So, not only did Cisco/Linksys cheap out on the AMOUNT of RAM, they cheaped out on the TYPE of RAM.

I thought about that, but I wasn't sure if I could get the parts off without damaging them. I was warned that extraction can sometimes melt thin TSOP's, rendering them unusable. I decided to go ahead and buy new, unused components to avoid soldering a damaged component down. (That, of course, assumes all three dhips are good from the factory, but I've had very few bad parts from Digikey)

(Last edited by jshamlet on 28 Mar 2007, 15:40)

With the right tools, you can get the chips off without damaging them. Like hotair with a special nozzle to fit the TSOP-54.

Anyhow, as a first time mod, I bought two new parts from digikey as well, $8 a piece for Qimonda ram. It's good to test to know the ram is not responsible for anything that doesn't work afterwards.

When I do get my ram, I'll make some photos and a write up.

As promised, here is a quick write-up on the mod:

http://www.dd-wrt.com/wiki/index.php/La … _SDRAM_MOD

Please, if someone has time, please put this into the openwrt wiki. It was down and my first time posting on a wiki.

I'm not sure if it was a hardware problem, or a soldering problem, but my first attempt failed - resulting in a destroyed router.

I was able to pull the Hynix part with no problem using a hot-air gun. I used a bit of kapton tape to keep the discretes from flying off the board. Took a few rounds, but the chip slid off with no problems. I let the board cool before cleaning the pads.

I even got the new SDRAM chip on just fine as well. It did take a bit to find all the opens, and get the soldered down, but eventually all 54 pins were firmly attached.

Then, nothing. Not even a peep out of the bootloader. I tried disconnecting the TX line on my LVTTL->RS232 converted, but I didn't even see the + character. I tried comparing each pin to a working router with a 'scope, and everything looked good. I saw activity on the data/address lines, and the clock enable pins were being pulled to the correct level.

I then tried to pull the Micron SDRAM up, and put the old Hynix chip back down - which is when I lifted the pad. Unfortunately, the signal went to a hidden via, and I couldn't find where it came back out for a repair. Rather than keep going, I just pulled the antenna, and tossed the router.

At this point, I'm not sure if I chose an incompatible SDRAM chip, damaged the part during assembly, or just had a bad solder joint. I doubt the last one, because I reflowed all the solder after the first boot failure. (ran the hot-air gun over the pins until the solder reflowed). I visually inspected for shorts and opens, found a few opens (which I fixed), and no shorts.

The only other thing I can think of that might have caused a problem is when I used an old tooth-brush dipped in isopropyl alcohol to clean the flux off the board. I wouldn't have thought that could zap a chip, but it's worth noting.

The SDRAM I have is 4Mx16x4 (16-bits wide, 4banks, 4Mb/bank). The Hynix SDRAM is 2Mx16x4 (16-bits wide, 4 banks, 2Mb/bank)

At any rate, I'm not going to sacrifice another router until I've yellow-lined both datasheets thoroughly.

I find heatguns tend to damage the chips unless you have the nozzle designed for tsop 54 and you don't heat it too long. I had a problem with one of my sdram chips but I just took it off and put a second one and it works.

Alright - I just booted a32MB Fonera. I'm not sure what *I* did, but our tech swapped the chip for me, and it booted just fine. I think the lesson here is that I stink at SMT rework, though it is possible I just got unlucky, and had a bad part.

Redboot is reporting the full amount, just as in the HOWTO.

+Ethernet eth0: MAC address 00:18:84:xx:xx:xx
IP: 192.168.1.254/255.255.255.0, Gateway: 0.0.0.0
Default server: 0.0.0.0

RedBoot(tm) bootstrap and debug environment [ROMRAM]
Non-certified release, version UNKNOWN - built 01:14:04, Mar 14 2007

Copyright (C) 2000, 2001, 2002, 2003, 2004 Red Hat, Inc.

Board: ap51
RAM: 0x80000000-0x82000000, [0x8003f6e0-0x80fe1000] available
FLASH: 0xa8000000 - 0xa87f0000, 128 blocks of 0x00010000 bytes each.
== Executing boot script in 10.000 seconds - enter ^C to abort
^C
RedBoot>

What is NOT working is that the built-in FON firmware doesn't appear to recognize the extra memory.

Mem: 13480K used, 776K free, 0K shrd, 1100K buff, 2028K cached
Load average: 1.29, 0.85, 0.37    (State: S=sleeping R=running, W=waiting)

  PID USER     STATUS   RSS  PPID %CPU %MEM COMMAND
 1544 root     R        424    19  0.9  2.9 top
  740 root     S        452     1  0.7  3.1 N50chillispot
 1973 root     S        300   740  0.5  2.1 sleep
  743 root     S       4912     1  0.0 34.4 chilli
   19 root     S        528     1  0.0  3.7 ash
  609 root     S        448     1  0.0  3.1 hostapd
   16 root     S        444     1  0.0  3.1 rcS
  477 root     S        428     1  0.0  3.0 crond
  484 root     S        424     1  0.0  2.9 httpd
  438 root     S        420     1  0.0  2.9 httpd
  591 nobody   S        412     1  0.0  2.8 dnsmasq
  632 root     S        404     1  0.0  2.8 udhcpc
  432 root     S        400     1  0.0  2.8 dropbear
    1 root     S        396     0  0.0  2.7 init
   20 root     S        396     1  0.0  2.7 syslogd
   17 root     S        380     1  0.0  2.6 logger
   22 root     S        360     1  0.0  2.5 klogd
  488 root     S        328     1  0.0  2.3 watchdog
  489 root     D        328   488  0.0  2.3 watchdog
  121 root     S        284     1  0.0  1.9 lock

Anyway, nice work with this mod. Thanks!

(Last edited by jshamlet on 12 Apr 2007, 16:25)