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RE: eb40a target submitted


512K bytes out of 2Mbytes doesn't seem so small to me to ignore.  But
just
the fact that you got it working is wonderful!
(In the below, loaddr = 0x01000000 and hiaddr = 0x01100000)
If you load/run Redboot ROMRAM at hiaddr why would you 
want to flash it at loaddr?  Why doesn't it just overwrite
itself at hiaddr?  If you have linked Redboot at
loaddr, would it be possible to change it to hiaddr? Perhaps that
would solve the problem?
Also, I didn't think it mattered to Redboot were the program
was linked.  You can load the program into RAM, then program it
into flash at hiaddr.
James

> -----Original Message-----
> From: Tim Drury [mailto:tdrury@siliconmotorsports.com] 
> Sent: Monday, July 22, 2002 7:29 PM
> To: ecos-discuss@sources.redhat.com
> Subject: Re: [ECOS] eb40a target submitted
> 
> 
> 
> Another note that I forgot about:
> 
> The FLASH on the eb40a is Atmel AT49xxxx which Jani
> graciously gave the source code to me.  The AT49 FLASH
> is divided into two planes (smaller A and larger B).  Because
> the drivers assume equal sized sectors I simply ignored the
> A plane.  This is a large FLASH device and plane A is pretty
> small - besides Angel is burned into it.
> 
> This has a side effect.  Assume the FLASH is mapped to
> 0x01000000.  Plane A goes up to 0x01010000 -1 bytes
> so I told the driver that this section is unusable.  When you
> load redboot_ROMRAM into 0x01100000 (the upper half
> of flash), you cannot have it load a new version of redboot
> on top of itself like you can with the EB40 and its more sane
> FLASH.  This is because when the redboot_ROMRAM is
> mapped down to 0x01000000 by setting the onboard jumper,
> you cannot tell the redboot running in RAM to burn the new
> redboot image file into 0x01000000 because the driver considers
> that address unusable.
> 
> So if you want to load a new version of redboot_ROMRAM, you
> have to first load up the RAM version of redboot via Angel,
> then run the RAM version of redboot to load the ROMRAM
> version of redboot.
> 
> Ah well.  Perhaps someone can figure out how to make the
> AT49 FLASH work with its differing sector sizes.
> 
> -tim
> 
> 


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