Upgrading WL-700gE flash to 8MB

You know, WL-700gE has only 2MB of flash on the board. It's too small to flash complete firmware to the device itself, what's why original firmware only has a kernel and initial loader in the flash itself. The rest is being loaded from the HDD on startup.

As I've my own firmware for the bunch of WL-500g router series I've decided to upgrade built in flash up to 8MB to match WL-500g Premium size. In fact, both WL-500gP and WL-700gE seems to be a twins: the PCBs is mostly identical near the CPU. Even component labels are the same.

So, the idea is simple: just replace the flash and surroundings with things similar to WL-500g Premium.

What do you need to perform a mod?

Good soldering skills at first (the board is Pb Free!). :)
8MB flash chip which is pin compatible with S29GL064M-90TFIR7, which is used on the WL-500g Premium board (i.e. Am29LV641 family, MX29LV640, but not the Am29LV640!). Before ordering it, check datasheet to match packaging and pinout: pin 9 should be A21! If possible try to avoid using MirrorBit chips (they've letter M in suffix)
As WL-700gE does not have JTAG header, you have to use external flash programmer to pre-program bootloader (CFE).
Two 0 Ohm "resistors" (optional ;), as you could always do just a solder drop.

Doing it

Buy a flash chip
Preprogram it with CFE at address 0 (you could also read first 256KB from the original flash to get CFE image)

cat /dev/mtd/0 > /your/usb/stick/mount/path/cfe.bin

Disassemble WL-700gE completely and remove top shield
Remove original MX29LV160 chip and solder your new programmed chip
Remove a 0 Ohm from R180 and put it to R179
Put a 0 Ohm to position labeled R181
Replace original resistor (10 kOhm?) labeled R185 with 0 Ohm

Done! It should now looks like below (well, the RAM is also doubled in size):

Using it

Once you've completed this you will have to reflash firmware to your device. You could also use my firmware labeled WL700g (as it would finally fit to flash).

Discussion

Do not mail me directly, use wl500g.info forum instead.

oleg

Posted: 2008-01-28