[coreboot] SPI controller and Lock bits

Sam Kuper sam.kuper at uclmail.net
Sun Sep 30 00:18:07 CEST 2018

On 29/09/2018, ron minnich <rminnich at gmail.com> wrote:
> On Sat, Sep 29, 2018 at 1:59 PM Sam Kuper <sam.kuper at uclmail.net> wrote:
>> Small momentary switches cost pennies and laptops usually have about a
>> hundred of them fitted, of various kinds. (Power on/off/suspend;
>> volume up/down; keyboard keys; maybe others.) So, fitting laptops with
>> momentary switches is definitely acceptable to manufacturers.
> I'm guessing you don't work in a company that designs or builds laptops :-)

True enough. I have worked at a company that designed and built other
consumer electronics, though, and spent time with people speccing PCBs
and custom silicon.

> b/c they agonize over parts like this. I ran into one situation where the
> ODM removed a single pulldown to save cost. One little
> almost-too-small-to-see part which cost a fraction of a cent. But a laptop
> BOM is a consequence of thousands of decisions of this type.
> Nope, the switch is definitely a non-starter, esp. given that there are
> solutions that don't require it.
> It's not just the part. A single simple part like that has all kinds of
> follow-on effects that are not obvious unless you've been at a company
> which designs and builds consumer electronics.

Thank you for the perspective. I do understand that changing one
component can affect others.

Purism isn't a typical laptop company. The addition of hardware
switches, to control webcam, mic and Wi-Fi, is one of the USPs for
their Librem models. These undoubtedly had knock-on effects for the
BOM. Purism was undeterred by that. In that context...

I'm just asking for one more switch.

So, Youness and others at Purism: if you are reading this, please do
spec a momentary switch to control flashing on future Librems. Your
security-conscious users will thank you for it.

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