Flashing a BIOS chip with Bus Pirate
From DP
Let's assume that your starting conditions are the following:
1) You have a computer with installed GNU/Linux or BSD operating system
2) You want to start flashing the BIOS images to the motherboards of other computers - either to restore their closed source proprietary BIOS after a failed update; or to replace it with a free/open source alternative, which is:
coreboot + SeaBIOS payload. You could check Supported Motherboards list to see if your board is supported or what board it is better to buy
3) You already have a Bus Pirate, doesn't matter if it is v3 or v4
This article will help you to set up a working BIOS flashing environment by providing the advanced description of hardware side of the question
Contents |
Getting the right tools
NOTE: although this part could be viewed as a kind of advertisement by some of the readers, it just gives you an example of what tools could be suitable and where you could buy them (and I am giving multiple examples, not focusing at one seller or product!) It is strongly encouraged that you additionally research before making the final purchase decisions, because:
1) the prices could change
2) the seller's rating could drop
3) better tools could appear
Also, this article describes flashing SOIC8 chips as an example. There could be a slightly different method of connectivity to other types of BIOS chips, especially for those types of chips which don't have available-for-purchase test clips and/or whose pins are not physically exposed to a user, so that a user can't connect to them without soldering...
Soldering iron tool (temperature adjustable) and supplies
While trying to reduce the expenses as much as possible I found two great choices:
1) Cheap soldering tool, stand and set of iron tips ($6.56)
2) ATTEN AT-SS-50, true ceramic core, stand and 1 iron tip (~$27.72)
Although 1) is a great cost effective choice, its' "ceramic" core is pseudoceramic in fact - nichrome spiral; that means: slower time to heat, no thermal stabilization (you would need to control a temperature switch constantly to remain near your desired temperature), also it heats a lot after 15-20 mins of usage - uncomfortable for fingers - so need to make a break
2) is the cheapest true ceramic core soldering tool with adjustable temperature that I was able to find. It has a great quality, quick starting time, working temperture stabilization and does not overheat your fingers. But it is more expensive than "1)", so you need to decide if "1)" is enough for your projects or you need a better "2)" tool
Supplies: will add later, meanwhile you could look by yourself
1P wires
Copper has 1.65x times better electrical conductivity than aluminium
Many people are using 1P aluminium wires and are happy with them. But this BIOS flashing is very important task, so why settle for less? Here are some 12 strands pure copper 1P wires:
[*] 40 pcs of 20cm copper wires (~$2.25)
[*] 40 * 10 = 400 pcs of 20cm copper wires (~$13.80)
As you see it is possible to get 400 for a price of 200 by buying at bulk, so if you need a long lasting supply or would like to share with friends - it could be a good idea to consider 400 pcs option.
It is recommended that the wires used for BIOS flashing are less than 20 cm length. But 20 cm copper wire would be the same electrical conductivity as 20/1.65 = 12 cm aluminium wire, good enough; and if you still have some problems while flashing - you wouldn't need to shorten a copper wire as much as you would have needed to shorten an aluminium wire
1P pins
Better to buy 800 pins - that would be enough for a long time ;)
[*] 800 pins, gold plated (?) (~$4.34)
[*] 800 pins, copper plated (~$3.70)
Gold is more resistant to corrosion, but copper has 1.4x times better electrical conductivity. Also, these items could be both copper in fact, so you might go for a cheaper option
SOIC8 test clip
There are at least five types of possible options for SOIC8 test clip:
[*] Standard type 1 - clamp only (~$2.15)
[*] Standard type 2 - "cheap and good" (~$2.60)
[*] Standard type 3 - "updated version, updated quality" (~$3.85)
[*] Standard type 4 - "wider gold plated needle" (~$6)
[*] Advanced type - high quality with bent 1.27mm 1P pins (~$9)
Standard types 2/3/4 already have the long and thin aluminium wires attached to them - not good for BIOS flashing. "Advanced type" is more expensive, but it has 1.27mm 1P pins that you could easily connect copper wires to, while for the standard types you will have to solder them.
You could just buy a clamp (standard type 1) if your soldering skills are good - but these pins are too close to each other so it's inconvenient to solder. If not advanced type, it is better to get a standard type 2/3/4 then you cut these aluminium wires leaving about 2 cm part that is soldered to a test clip, then you remove the insulation and solder a copper wire to each of the aluminium wires individually
Shrinking tubes
If you encountered some problems while flashing and want to shorten your 20 cm copper wires to 10cm (by cutting the wire in 3 parts: 6cm + 8cm + 6cm, and soldering two 6cm parts together) electrical insulation is a good idea to prevent a possibility that a soldering joint in the middle of your wire could touch a motherboard (possibly causing a hardware damage by shortening) or a soldering joint of another wire (causing a failed BIOS flashing)
328 pcs packs (5 colors, 8 sizes) are quite a cost effective solution:
[*] 1st example (~$3.42, Malaysian post - slower than Chinese post)
[*] 2nd example (~$4.25, Chinese post)