[OLPC-devel] FLASH part programming

[Ray.Tseng at quantatw.com]

Ron,

Actually EC did not implement this mechanuism in Pre-A and A test board. It's always write-enable now.
One thing to clarify is that Pre-A test board boot from socketed ROM, the SPI ROM is disabled; A test board boot from SPI ROM, the socket is empty.

Ray Tseng 6/9/06 
   

-----Original Message-----
From: Jim Gettys [mailto:jg at laptop.org] 
Sent: Thursday, June 08, 2006 7:59 PM
To: Ronald G Minnich
Cc: devel at laptop.org; Mark Foster; Ray Tseng (曾文瑞)
Subject: Re: [OLPC-devel] FLASH part programming

It is hanging off the embedded controller.  Ron, do you want/need schematics?

I know the long term intent is that the write enable line to the serial flash will be entirely under control of the EC code, and there will be a protocol for talking to it to turn on write enable.

The EC code will enforce holding a keyboard key down before honoring this request.  The point of this is to ensure a virus/worm cannot turn our hundred dollar laptops into hundred dollar colorful building bricks without human intervention, at no additional cost and allow updates without having to open the machine physically.  Phishing attacks against the boot rom will still be possible, but this is a pretty good defense against automated attacks taking out all our systems at once.

That being said, there is a tool we got from Quanta which is able to write the serial flash (in fact, the most recent machines we received in Cambridge had the wrong version of the Insyde BIOS): this tool runs from DOS/FreeDOS and will write the serial flash, so I know it is possible.
(and the EC code does not currently enforce the key down requirement).

Ray Tseng or Mark Foster will know the exact details.
                                      Regards,
                                        - Jim

                                    
On Wed, 2006-06-07 at 21:23 -0600, Ronald G Minnich wrote:
> I want to start looking at a linux tool for programming the serial 
> flash part.
> 
> Anybody know where that enable jumper is? I need to modify the 
> linuxbios flashrom utility to do this.
> 
> thanks
> 
> ron
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--
Jim Gettys
One Laptop Per Child