[flashrom] flashing MX25L3205DM2I-12G

[Stefan Tauner]

On Wed, 31 Oct 2012 09:40:02 -0400
"Pupic P." <ladypupic at gmail.com> wrote:

> Hi everyone,
> 
> I have a MacBook Pro (13" mid-2009) who, I think, suffers from a bad
> firmware flash : from nowhere, or after an update, it makes 9 beeps when
> powered on (3 short, 3 long, 3 short) and nothing else. I have found
> references from similar cases when people seemed to have recovered by
> rewriting a good firmware with flashrom and buspirate (
> http://ho.ax/tag/firmware/).
> On my machine I have :
> - a chip labelled MX25L3205DM2I-12G
> - buspirate 3.6 (v3b, firmware 5.10)
> - flashrom v0.9.6.1-r1620
> - hooked (while the chip still on the motherboard (no power, battery out))
> : pin1->CS, pin2->MISO, pin4->GND, pin5->MOSI, pin6->CLK, pin8->3.3v
> 
> * Pins 3,7 not connected.
> * I also tried pins 3,7,8 together with the same result.

they need to be connected, in this case they need to be set to a
distinct potential (namely vcc), but you should always connect all pins
of an IC unless noted otherwise in its datasheet. floating pins are
evil.

> What I get is flashrom ending with :
> Probing for Generic unknown SPI chip (RDID), 0 kB: RDID byte 0 parity
> violation. probe_spi_rdid_generic: id1 0x00, id2 0x00
> Found Generic flash chip "unknown SPI chip (RDID)" (0 kB, SPI) on
> buspirate_spi.
> Probing for Generic unknown SPI chip (REMS), 0 kB: probe_spi_rems: id1 0x0,
> id2 0x0
> Found Generic flash chip "unknown SPI chip (RDID)" (0 kB, SPI).
> 
> Any idea why?

this means that MISO is always read as low. this can have a number of
reasons. one of example is that pin8 is also connected to a number of
other components that need more power than the bus pirate (or whatever)
can deliver. see also http://flashrom.org/ISP
-- 
Kind regards/Mit freundlichen Grüßen, Stefan Tauner