Re: The power of the GPL

[telford]

Graham Murray <newspost@gmurray.org.uk> wrote:
> <telford@xenon.triode.net.au> writes:

>> Not too many manufacturers have the capability to make their own custom
>> CPUs so there is always an option of replacing the ROM or replacing the
>> CPU with a generic model containing decent bootstrap code.

> True, but some of the CPUs used in embedded systems have a boot PROM
> on the silicon and the customer can, even for moderate quantities,
> order 'masked' parts with their code blown into the (One Time
> Programmable) PROM.

So you buy an identical CPU with flash memory (one digit different in
the part number) and you replace the entire CPU. I guess they could use
BGA parts soldered to the main board to make them difficult to replace
but whenever there is a generic part with identical properties but
without the proprietary ROM there is usually an easy upgrade path.

The tricky bit comes when the CPU is on chip with a bunch of specialty
peripheral devices and no generic equivalent exists, or when the CPU
contains enhanced processing capabilities that can't be replaced with
software.

        - Tel