[flashrom] [PATCH][RFC] uisp_spi programmer support

[Andrew]

Stefan Tauner писал 02.06.2014 21:02:
> On Mon, 02 Jun 2014 11:35:31 +0400
> Andrew <andrew at ncrmnt.org> wrote:
> 
>>    * Programmer lock/unlock (Another accidentally started instance of
>> flashrom won't screw us up anymore)
> 
> chromiumos' flashrom has something like that implemented globally IIRC.
> It does not make too much sense to implement that for a single
> programmer... could two instances get access to the interface
> concurrently at all?

Okay, I'll drop it then. Thanks.
For an stm32-based one it can be possible and makes sense to 
concurrently interact
with several SPI chips connected to several hardware SPI interfaces e.g. 
stm32 has the guts
to do so without any slowdowns, so I think of implementing this feature 
in the core code, yet
leave it out for avr.

For STM32 it might also make more sense to export a /dev/ttyACMx for 
each
SPI interface and use serprog protocol, but that needs testing.
On avr vusb-based cdc_acm is damn slow for device->host transfers and 
doesn't work
for some usb hosts. And I'm not sure it will be the fastest way on a 
stm32 either.

STM32 right now requires love, since ST's usb device stack is utter 
unusable crap and
definitely has a race condition somewhere that causes enumeration 
problems. I'm playing
with it for my pet antares project ( http://github.com/nekromant/antares 
), but ST's code
needs a lot of refactoring before it can be used at all (or even a 
rewrite from scratch).

> 
>> I will be also making some new hardware based on STM32, that should
>> provide a real speed boost,
>> but since the actual chips are stuck somewhere between China and 
>> Russia
>> this may take a while.
> 
> I have a discovery board laying around with an STM32F4... but have
> never plugged it in yet :/

Actually, you can use even an stm32f1 discovery as a flashrom programmer 
with stlink
as the interface ;) The stlink will deliver ~25Kb/sec speeds. I've done 
this a while
ago using this hack of mine: 
http://ncrmnt.org/wp/2013/05/06/stlink-as-a-serial-terminal/
when I had to urgently debrick a router.
But it was utter hackery and I didn't bother to send in the patch to 
flashrom.
ST also has COMPLETELY different usb device stacks for stm32f4x and 
stm32f1x with
COMPLETELY different API. (And both look weird as hell.) For now I 
target stm32f1x.


>> My goal is to make a blazing fast programmer with BOM cost of under 5$
>> (and possibly parallel
>> flash programming support as well).
> 
> You might be interested in http://qiprog.org/
> The GSoC student that made it last year sadly joined the US armed
> forces, so don't expect too many answers regarding it from him.
> Peter Stuge was the mentor and is probably the one to ask if you have
> questions not answered by the website/code or last year's blog articles
> http://blogs.coreboot.org/blog/author/mrnuke/

Thanks for the links, I'll have a look. But I guess it will be faster 
for me
to design it from scratch, I guess. Not a big deal, anyway.


-- 
Regards,
Andrew