[U-Boot-Users] Re: [Question About NAND BOOT In SMDK2410

Wolfgang Denk wd at denx.de
Wed Oct 29 03:10:40 CET 2003

In message <8D7C5F56B409554D9D46AC22195807F3061DD3 at exchwenz01.dmcwave.co.nz> you wrote:
> What do you have in mind? Boot U-Boot from a Smart Media Card? [Can't
> be done.] 

[Dear Rod, please  stick  with  standard  quotin  rules  -  read  the
Netiquette if necessary.]

> Wolfgang it is code and with code anything can be done I have written code

Arghhh... I have yet to see any processor  that  can  "boot"  (i.  e.
start  fetching instructions out or reset) from an NAND flash device.
So far, all of them need some software to  do  this,  which  must  be
loaded from a _real_ boot device.

> to read and write to a SmartMedia card from an 8051 8-bit micro.  If I had a

But I guess the first instruction the 8051 executed  was  NOT  loaded
from  the  SmartMedia card? I guess there was some ROM which you used
as boot device, right?

> need to read a kernel out of SmartMedia then I could do that just as eaisly.

Please read again what  I  posted.  What  does  "boot"  mean?  Is  it
bootstrapping  a  processor out of the reset condition into some sort
of software (typeically a monitor program  like  U-Boot),  or  is  it
using a bootloader to bootstrap an operating system?

> At 50MHz processor I could even do an effective ECC and still read it out.

Can't be done. It won't start fetching instructions  from  SmartMedia
when you relese the reset pin.

> I have not done this but I can not think of a reason why it cannot be done.

Think again. Read again. Read before posting, please.

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
It is dangerous to be sincere unless you are also stupid.
                                                - George Bernard Shaw

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