Re: u-boot debug, was: Re: U-boot on RPI3, sees disk but won't boot it

> Am 03.10.2022 um 02:46 schrieb bob prohaska <fbsd@www.zefox.net>:
> 
> On Sun, Oct 02, 2022 at 10:18:28PM +0200, Klaus K??chemann wrote:
>> 
>> hard to read and remember every log but I thought Bob wrote about aprox. 30 successful reboots after the mdelay patch,
> 
> That is correct. Shortly afterward I tried a second usb-sata enclosure.
> 
> I didn't immediately notice a difference and though it didn't matter.
> You comments served to make me think again.
> 
>> while of course that could be coincidence, who really knows what happens in this untrackable inconsistent behavior of the usb-boot?!
> 
> Unfortunately in this case, human inconsistency (my own, alas) was compounding at least
> part of the trouble. 
> 
> The more troublesome bridge contains a JMS577 chip, the less troublesome JMS576.
> https://pdf1.alldatasheet.com/datasheet-pdf/view/1136441/JMICRON/JMS576.html
> Contains a brief description, but I didn't see much quantitative information.
> 
> I've reverted the host to the less troublesome JMS576 and will try to 
> reproduce some of the earlier results as a sanity check.
> 
> Thanks for rattling my cage!
> 
> bob prohaska

turns out that maybe you as a professional physicist are the one with the biggest chance to free the Pi3 boot behavior out of inconsistenteny :-)
Many years ago I sold tons of self modified power supplies for Mac machines, which enabled the FireWire functionality, I found out some tricks to solder some Cables , but I never knew exactly why it worked, I even didn’t use an oscillator or any measurement :-)
Some people in the web say that it’s the ethernet port on the USB hub of the Pi3 which stops to give 25MHZ boost to the USB port at boot,
They tricked it out by plugging RNG or oscillator or something like that ,
No way for me as an electronics illiterate to give an appropriate answer what that does mean :-)
Sure you have more capability to test which JMS577 and JMS576  chip exactly gives what kind power(or Speed;-) to the Usb hub.

Best of course would be to get rid off external boot loaders like u-boot ans use bootcode.bin,
But that would be a software project little too big for us, I guess.


thanks

Regards


Klaus