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Date:      Mon, 3 Oct 2022 03:28:58 +0200
From:      =?utf-8?Q?Klaus_K=C3=BCchemann?= <maciphone2@googlemail.com>
To:        bob prohaska <fbsd@www.zefox.net>, Mark Millard <marklmi@yahoo.com>, freebsd-arm@freebsd.org
Subject:   Re: u-boot debug, was: Re: U-boot on RPI3, sees disk but won't boot it
Message-ID:  <DF45AD0E-1B9A-418A-8398-DAB7AF613464@googlemail.com>
In-Reply-To: <20221003004624.GA3381@www.zefox.net>
References:  <E3A1C678-8C47-4283-9F9F-4C9011DB8A2B@yahoo.com> <20221001174724.GA98055@www.zefox.net> <ABFDD634-5CB6-4DAE-B4DE-629CE7E4FE06@yahoo.com> <20221001193033.GA98348@www.zefox.net> <46226720-D867-4AD3-9559-A4365FAC28C4@yahoo.com> <6DB88FC9-629C-43E6-9673-32640FC547F7@yahoo.com> <20221002182049.GA2255@www.zefox.net> <5FFDAA6A-AD8C-4E40-A2EB-4082E5086679@googlemail.com> <38DFEB91-AC60-4FD1-8088-95B0A06C5E5D@yahoo.com> <EEC43DA1-6B68-4FDD-A68A-A3055E86E407@googlemail.com> <20221003004624.GA3381@www.zefox.net>

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> Am 03.10.2022 um 02:46 schrieb bob prohaska <fbsd@www.zefox.net>:
>=20
> On Sun, Oct 02, 2022 at 10:18:28PM +0200, Klaus K??chemann wrote:
>>=20
>> hard to read and remember every log but I thought Bob wrote about =
aprox. 30 successful reboots after the mdelay patch,
>=20
> That is correct. Shortly afterward I tried a second usb-sata =
enclosure.
>=20
> I didn't immediately notice a difference and though it didn't matter.
> You comments served to make me think again.
>=20
>> while of course that could be coincidence, who really knows what =
happens in this untrackable inconsistent behavior of the usb-boot?!
>=20
> Unfortunately in this case, human inconsistency (my own, alas) was =
compounding at least
> part of the trouble.=20
>=20
> The more troublesome bridge contains a JMS577 chip, the less =
troublesome JMS576.
> =
https://pdf1.alldatasheet.com/datasheet-pdf/view/1136441/JMICRON/JMS576.ht=
ml
> Contains a brief description, but I didn't see much quantitative =
information.
>=20
> I've reverted the host to the less troublesome JMS576 and will try to=20=

> reproduce some of the earlier results as a sanity check.
>=20
> Thanks for rattling my cage!
>=20
> 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=E2=80=99t use an oscillator or any measurement :-)
Some people in the web say that it=E2=80=99s 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




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