[ECOS] ECOS/Redboot -- Several Questions

[ECOS] ECOS/Redboot -- Several Questions

[Michael Dorin]

Hello,

I have an 860T based board and am trying to convert
the MBX templete.  However a couple differences:

* My board has CS0 tied to address 0.  I believe the
wants to boot from 0xfe000000.  I don't have ram
at 0.  I have changed the ram.ldi and rom.ldi files
in the pkgconf directory.  I have changed the
lib/target.ld files.  

I can't seem to get a good link though.  

Where might I be missing something?

Second question...
Is it bad that 0 is my flash address?

Thanks,
 Mike

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Re: [ECOS] ECOS/Redboot -- Several Questions

[Gary Thomas]

On Thu, 2005-04-28 at 12:06 -0700, Michael Dorin wrote:
> Hello,
> 
> I have an 860T based board and am trying to convert
> the MBX templete.  However a couple differences:
> 
> * My board has CS0 tied to address 0.  I believe the
> wants to boot from 0xfe000000.  I don't have ram
> at 0.  I have changed the ram.ldi and rom.ldi files
> in the pkgconf directory.  I have changed the
> lib/target.ld files.  
> 
> I can't seem to get a good link though.  
> 
> Where might I be missing something?
> 
> Second question...
> Is it bad that 0 is my flash address?

Yup - poor choice.  You have total control over this during the
machine initialization, so it's much better to map the FLASH (CS0)
up high, e.g. 0xFE000000, and put the RAM (typically CS1) at 0x0.

Also, use the viper as a better template for 860T starting point.

-- 
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
------------------------------------------------------------


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Re: [ECOS] ECOS/Redboot -- Several Questions

[Frank Robbins]

I think you may need to read the PQ1 manual a bit more ......

The PQ1 comes out of reset with CS0 owning all of the 4Gig address space 
hence the flash is always normally at zero to start with. Then normally 
this is then reduced and relocated up to  0xfe000000  and the SDRAM then 
located back down to zero. Hence the boot loader starts in flash offset 
of 0x00000000 then runs with offset 0xfe000000 in flash then usually it 
copies its self into SDRAM (.. after setting this up of course.)  from 
address offset 0x00000000.

Please note: The MBX template is VERY OUT OF date 

Regards


Frank Robbins

Email: frank.robbins@analogue-micro.com

web:http://www.analogue-micro.com

Analogue & Micro Ltd

9 Clytha Park Road

Newport

NP20 4PB

UK (Great Britain)


Tel : 44 (0)1633 666787

Fax : 44 (0)1633 666788



Michael Dorin wrote:

>Hello,
>
>I have an 860T based board and am trying to convert
>the MBX templete.  However a couple differences:
>
>* My board has CS0 tied to address 0.  I believe the
>wants to boot from 0xfe000000.  I don't have ram
>at 0.  I have changed the ram.ldi and rom.ldi files
>in the pkgconf directory.  I have changed the
>lib/target.ld files.  
>
>I can't seem to get a good link though.  
>
>Where might I be missing something?
>
>Second question...
>Is it bad that 0 is my flash address?
>
>Thanks,
> Mike
>
>  
>

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