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Topic: Accessing laptop flash in place - no luck, 0xFF's (Read 2082 times) previous topic - next topic

Accessing laptop flash in place - no luck, 0xFF's

First of all sorry I'm not really a hardware guy, I work mostly with software.
I try to ISP-read the flash from my laptop, and so far have no luck whatsoever on laptop's own power, although sniffing works (only a little bit before BP gets overwhelmed with data). Shortly after that the SPI bus quietens I try to send 0x9F in, but no matter what I send I always get 0xFF's back. Is this common? What could it be?
I was thinking of powering it differently - to power down the laptop and power just the flash chip, but I hear that's dangerous for the health of the flash and/or other connected devices. How big is this risk really?

Re: Accessing laptop flash in place - no luck, 0xFF's

Reply #1
BTW I saw that BP can't drive flash pins low/high enough. CS high was ~1.4V (Vpullup 3.3V). DI low was ~1V.

Is there any way to make BP drivers stronger?

Re: Accessing laptop flash in place - no luck, 0xFF's

Reply #2
how did you measure the voltages on the CS and DI lines?

the most reliable way to do this is to remove the flash. the BP is not capable of powering an entire laptop. you can be sure with the chip removed nothing else from the laptop is interfering.

Re: Accessing laptop flash in place - no luck, 0xFF's

Reply #3
you can be sure with the chip removed nothing else from the laptop is interfering.