[Techtalk] what is bricking?

[Miriam English]

Often the EEPROM can't be re-flashed because, in a peculiar twist, the 
flashing routine is in the EEPROM. It gets loaded temporarily into RAM 
for the rewriting. This is why they say not to turn off the machine 
while doing a ROM upgrade. Heaven help you if the power goes out while 
re-flashing. The program in RAM evaporates and the ROM is left in a 
useless state -- the computer does a wonderful imitation of a brick. 
Hence the term. Often the EEPROM is soldered to the board, making any 
attempt at salvage doomed. :(

I have a cute little computer here that I can't bring myself to throw 
away even though it is impossible to resuscitate.

Incidentally, the impossible-sounding process of flashing a ROM via a 
program that is in the chip itself being written is a little like the 
original almost paradoxical process in the "old days" of using a starter 
program to get a computer to begin executing programs. It was referred 
to as "bootstrapping" because it was considered to be a little like 
lifting yourself by your own bootstraps -- the computer couldn't run 
without loading software, but needed software to load it. We now call it 
"booting" our computers and it doesn't seem paradoxical anymore. :)

Cheers,

	- Miriam


Carla Schroder wrote:
> O gurus, what does it mean to brick a device like a wireless router? Is it
> correct to say it's corrupting the OS to the point where it cannot boot, and
> you cannot re-flash the EEPROM? But if you had a nifty little EEPROM programmer
> device thingy, and could safely pull the chip out of the router, you could
> restore it?
>
> Carla
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Carla Schroder, ace Linux guru and howto author
> 541-932-4817 PT
> carla at tuxcomputing.com
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-- 
If you don't have any failures then you're not trying hard enough.
  - Dr. Charles Elachi, director of NASA's Jet Propulsion Laboratory
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