[U-Boot-Users] Running U-boot in cache area.

[U-Boot-Users] Running U-boot in cache area.

[sathesh babu]

Hi,
    I am tring to run U-boot on MIPS 24KE processor.
      I have done MIPS 24KE cache initilization and configured it for write through  mode in the start.S file.
   
  If I specify SDRAM start address  as uncached area ( start with 0xa0000000), u-boot boots up and able to get the u-boot prompt.
   
  It I try SDRAM start address as cached area ( Start with 0x80000000), the u-boot comes up to relocation function and hangs.
   
  Could you please tell me what could be the problem.
  Did i mss any thing?.
   
  I see the same behaviour with write back mode also.
   
  Should i call any cache invalidation ( doing this as part of cache initilization in the start.S) or flush functions before calling relocation().
   
  I am  enabling primary cache only and no secondary cache.
   
  Thanks in advance.
   
  Regards.
  Sathesh
   

 				
---------------------------------
 Here?s a new way to find what you're looking for - Yahoo! Answers 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.denx.de/pipermail/u-boot/attachments/20070121/244dfa04/attachment.htm 

[U-Boot-Users] Running U-boot in cache area.

[Haavard Skinnemoen]

On 1/21/07, sathesh babu <sathesh_edara2003@yahoo.co.in> wrote:
> If I specify SDRAM start address  as uncached area ( start with 0xa0000000),
> u-boot boots up and able to get the u-boot prompt.
>
> It I try SDRAM start address as cached area ( Start with 0x80000000), the
> u-boot comes up to relocation function and hangs.

> Should i call any cache invalidation ( doing this as part of cache
> initilization in the start.S) or flush functions before calling
> relocation().

I don't know too much about MIPS, but I did write relocation code for
AVR32 not very long ago, and it runs with caches enabled the whole
time.

I would imagine that you have to clean (and optionally invalidate) the
dcache and invalidate the icache after copying the new code into
place. The easiest way is probably to do a full flush (i.e.
clean+invalidate) of the whole dcache and invalidate the whole icache
just before jumping to the relocated entry address.

Haavard

[U-Boot-Users] Running U-boot in cache area.

[Jerry Van Baren]

sathesh babu wrote:
> Hi,
>   I am tring to run U-boot on MIPS 24KE processor.
>     I have done MIPS 24KE cache initilization and configured it for 
> write through  mode in the start.S file.
>  
> If I specify SDRAM start address  as uncached area ( start 
> with 0xa0000000), u-boot boots up and able to get the u-boot prompt.
>  
> It I try SDRAM start address as cached area ( Start with 0x80000000), 
> the u-boot comes up to relocation function and hangs.
>  
> Could you please tell me what could be the problem.
> Did i mss any thing?.
>  
> I see the same behaviour with write back mode also.
>  
> Should i call any cache invalidation ( doing this as part of cache 
> initilization in the start.S) or flush functions before calling 
> relocation().
>  
> I am  enabling primary cache only and no secondary cache.
>  
> Thanks in advance.
>  
> Regards.
> Sathesh

This may be the FAQ.  Enabling caches typically enables bursting and 
disabling caches typically disables bursting (I'm not familiar with your 
MIPS - YMMV).  This class of RAM problems tend to show up only when 
bursting.
<http://www.denx.de/wiki/view/DULG/UBootCrashAfterRelocation>

gvb