Rockbox mail archive
Subject: Re: Need help with UART boot
From: Andreas Stemmer (groovingandi_at_gmx.de)
> > It's a SST39VF020, should be the right one I hope.
> You didn't tell the speed grade, but Archos was already using the lowest,
70ns, Archos uses 90ns
> > One thing I noticed: Why does the uart_boot tool
> > return a 512kb flash dump? The flash chip is supposed to have 256k x 8 =
> > 256kb, or am I wrong?
> The 512k is because I have used a double capacity chip when replacing
> mine. this is the max. for the footprint.
Ok. What happens if I try to program 512k into a 256k chip? I guess the
first 256k are flashed and afterwards the second 256k overwrite the first
> Then I guess you have shorted an address line? Try flashing a file with a
> single zero byte, and check if it appears in multiple places.
Bingo! I flashed a 256k file containing only 0xFF except one 0x00 at
position 0x00000. In the dump file, I have the 0x00 at 0x00000 and 0x20000
(and of course at 0x40000 and 0x60000 again). So if I interpret this
correctly, this means that A17 isn't connected properly. I can't check this
now, I don't have the necessary tools here. But I'll have a closer look at
it next week.
At least, I successfully booted the original Archos firmware from the first
half of your firmware_rec.bin. I copied the first half of it into the second
half of the file, flashed it and I've got the first half of the image in the
flash now. It doesn't help too much, but If I use the F1-startup, the second
half isn't needed obviously and the Archos firmware boots (confusing, heh?)
Anyway, thank you _very_ much so far. I'll investigate further and report
back when I've succeeded (or failed). If you ever happen to be in Munich,
I'll invite you to a beer or two.
Page was last modified "Jan 10 2012" The Rockbox Crew