On Tue, Apr 5, 2022, 7:02 AM Undiscussed Horrific Abuse, One Victim of Many <gmkarl@gmail.com> wrote:

notes: in the flasher source, it's designed for more than one interface, and use of the lpc chip is guarded by this:

uint8_t lpc_test(void) {

        nibble_hw_init();

FRAME is driven high for 1us and then allowed to drop for 1us.

        lpc_init();

calls nibble_init():

INIT is briefly dropped and then raised.

CLK is raised.

FRAME is raised.

calls nibble_write(0):

DATA lines are set high.

calls clock_cycle() 24 times.

The code for clock_cycle drops CLK then immediately raises it.

It goes on with more port writes. I may have made an error in transcribing the above.

I'm guessing the clock is happening faster than I have my oscilloscope set. Maybe I can spend some time learning it better and see the 1us FRAME behavior.

        if (lpc_read_address(0xFFFFFFFF)==-1) return 0;

        return 1;

}

flashrom itself doesn't seem to care about that check (although I haven't looked in the source): it just probes for a bunch of chips anyway.

so I guess the thing to do would be to look for the first lines that are engaged, and see where failure starts.