Coreboot hacking: How to solder a PLCC socket on your board

Desoldering station.

When trying to port coreboot (previously LinuxBIOS) to a new mainboard you're often confronted with a big problem: the BIOS/ROM chip on the respective motherboard is soldered onto the board (i.e., not in a socket).

This means that you cannot easily (hot-)swap the chip during development or for recovery purposes. So you basically have exactly one try to flash the ROM chip with a fully working/booting coreboot image. If that goes wrong your board is bricked.

Desoldering the chip

This makes it pretty much impossible to develop a coreboot port for such boards (and soldered-on ROM chips are becoming more and more common, unfortunately).

However, I've recently tried to replace the soldered-on (PLCC) ROM chip on one of my boards with a socket. What sounds pretty scary at first, especially given that I have almost non-existant soldering skills, turned out to be really not that hard. Also, it can be done with relatively cheap and readily available equipment.

I have written a short HOWTO for desoldering chips and soldering on sockets in the coreboot wiki, and also finished a video showing most of the process, which I hope will be helpful for others:

Place the PLCC chip


The video is CC-BY-SA 3.0, music is taken from ccmixter.org and is CC-NC 3.0 licensed. Video editing was done using Kino (which uses ffmpeg2theora for Ogg Theora export).

I also tried to upload the video to Vimeo, but first they told me to install the Flash 10 abomination (and there's no way I will do that). After browsing the help/forum pages a bit I found a traditional, non-flash upload form, but that then tells me that I cannot upload Ogg Theora videos. WTF?

Soldering the socket

The Ogg Theora video support feature request has been open for more that a year. Until that issue is fixed I'll just use other video services, thanks...

Comments

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nice info..

my father would love this kind of soldering kinda thing, too bad I doesn't inherit his skill..

Great tutorial. And glueing

Great tutorial. And glueing the middle part is a useful idea too.

Almost well done ;-)

In my experience, you should really glue the middle part in again after the soldering. Otherwise the chip might well slip below the contact springs of the socket, making it harder to get the chip out again and also can cause weird errors if the contacting between socket and chip fails sporadically.

regards,
Sven

Thank you!

Im working on aproject right now.
Thanks for this resources. It really help me :)

wow... this is an awesome

wow... this is an awesome tutorial..
i really love it.. thank

uploading oggtheora to vimeo

vimeo says they support uploading in ogg-theora now, but no hope for viewing in that format anytime soon.