[ECOS] Update on Axiom CME555 Redboot FLASH Memory Problems

[ECOS] Update on Axiom CME555 Redboot FLASH Memory Problems

[Mike Pashea]

Hi All,

I have an update to report on the Axiom CME-555 Redboot crash that I posted 
about last week.

I am certain that this is the same crash that Miguel Vega reported in 
earlier posts. However, I havenÂ’t seen any follow-up postings where he 
described any permanent solution.

Newer Axiom CME-555 boards have twice as much FLASH as the older boards 
because 29LV400Â’s are used instead of the 29LV200Â’s that were used when eCOS 
was ported to the CME-555. Modifying am29xxxxx_parts.inl to add the LV400 is 
pretty straightforward, but Redboot will crash with a segmentation fault on 
startup when it tries to run load_flash_config()located in flash.c.

I found that in addition to adding the LV400 description, you also have to 
change the OR1 mask in line 89 of cme555.S:

lwi     r4, 0xfff80032

should be changed to:

lwi     r4, 0xfff00032

The new mask prevents the MPC555 memory unit from generating a fault when 
the upper half of the 29LV400 is accessed.

One stray bit can sure cause a lot of problemsÂ…

Mike Pashea

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Re: [ECOS] Update on Axiom CME555 Redboot FLASH Memory Problems

[Andrew Lunn]

On Thu, Aug 30, 2007 at 12:15:34PM -0500, Mike Pashea wrote:
> Hi All,
>
> I have an update to report on the Axiom CME-555 Redboot crash that I posted 
> about last week.
>
> I am certain that this is the same crash that Miguel Vega reported in 
> earlier posts. However, I haven?t seen any follow-up postings where he 
> described any permanent solution.
>
> Newer Axiom CME-555 boards have twice as much FLASH as the older boards 
> because 29LV400?s are used instead of the 29LV200?s that were used when 
> eCOS was ported to the CME-555. Modifying am29xxxxx_parts.inl to add the 
> LV400 is pretty straightforward, but Redboot will crash with a segmentation 
> fault on startup when it tries to run load_flash_config()located in 
> flash.c.
>
> I found that in addition to adding the LV400 description, you also have to 
> change the OR1 mask in line 89 of cme555.S:
>
> lwi     r4, 0xfff80032
>
> should be changed to:
>
> lwi     r4, 0xfff00032
>
> The new mask prevents the MPC555 memory unit from generating a fault when 
> the upper half of the 29LV400 is accessed.
>
> One stray bit can sure cause a lot of problems?

Please could you submit a patch.

       Thanks
         Andrew

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