[ECOS] Redboot run image issues

[Rutger Hofman]

You may be aware that NAND flash requires a different type of driver 
than NOR flash. I have written an eCos NAND flash package that is in a 
pre-beta stage. It can be downloaded from
http://www.cs.vu.nl/~rutger/software/ecos/nand-flash/ and I welcome 
other testers. Since NAND flash requires a controller, chances are that 
you will have to write the bottom half of an NFC (NAND Flash Controller) 
device driver yourself. Hopefully the procedures to do that are outlined 
clearly in the documentation I provide.

However, I didn't attempt yet to support booting from the NAND. If it is 
supported at all, this is usually a two-step procedure: NFCs can 
sometimes be configured to load the first page(s) at boot time using 
some h/w procedure and run that code; these page(s) must contain code to 
load the rest of the bootstrap routines from following NAND flash pages. 
This is necessary because NAND flash cannot be randomly accessed, but 
can only be read a page at a time. The very first bootstrap page(s) will 
have to contain the code to read from NAND; and methinks it will not be 
easy to squeeze that code into one 2KB page, although it has been done 
of course.

Rutger Hofman
VU Amsterdam

joseph biswal wrote:
> My final intent is to get my redboot port to boot from the NAND flash.
> I am trying to run this image  from NAND flash but it gets stuck even
> before spitting anything on the console. Hence i turn to the BDI
> debugger where i try running the image from RAM and see if it works.
> 
> I am running on a MX31 based board with Freescale PDK1.4.
> 
> On Sun, Feb 22, 2009 at 9:30 PM, Chris Zimman <czimman@bloomberg.com> wrote:
>>> Whereas, when i load and runthe same redboot.bin from an existing
>>> working version of "redboot.bin " in RAM, i get the following
>>> : It gets stuck after printing "phys_addr=0x80100000" on the serial
>>> console. I am guessing something somewhere is wrong in the memory
>>> location but i am not sure where to start with. Would it be a problem
>>> with the linker script, mlt file or something else?
>>> ARe there other files in the HAL i need to look into? WHat actuallly
>>> happens when "LaunchRunIMage" in the redboot code  is invoked??
>> That's not going to work because the Redboot code isn't relocatable like
>> that.  Like you can't just load it and launch it from any location.  If I
>> understood you right, you're trying to launch a ROM or ROMRAM image from
>> within Redboot.  This is probably not what you want.
>>
>> You can configure a Redboot image to be launched from RAM, but this is
>> generally not necessary unless you're doing special things (eg. replacing a
>> Reboot ROM mode image, etc.)
>>
>> Beyond that, without seeing what's going on in the HAL setup
>> (hal_platform_setup.h), it's difficult to guess which of any number of things
>> it may be tromping over that could cause it to hang.
>>
>> I'm still missing what it is that you're ultimately trying to do here.
>>
>> --Chris
>>
> 


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