[ECOS] ram usage by redboot

[ECOS] ram usage by redboot

[Robert Brusa]

Hi all
I have configured a redboot (using ecos-3.0) for my target. Upon power up  
it writes out (among a lot of other stuff):

Platform: AT91ICB (ARM7TDMI)
RAM: 0x00200000-0x00220000 [0x00204c48-0x0021f300 available]
FLASH: 0x00100000-0x0013ffff, 1024 x 0x100 blocks

This makes me wunder:
a) What is the RAM up from 0x0021f300 used for? I can find no hint in the  
map.
b) It writes out the flash available on this machine. Why not the flash  
actually available for other programs?

Thanks for comments on this issue.
   Robert

-- 
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss

Re: [ECOS] ram usage by redboot

[Martin Laabs]

Hi,

> This makes me wunder:
> a) What is the RAM up from 0x0021f300 used for? I can find no hint in 
> the map.

IMHO it is used for the heap.

> b) It writes out the flash available on this machine. Why not the flash 
> actually available for other programs?

You can place programs into the flash. However they might need a 
slightly other configuration since flash is not writable (from the point 
of the static memory controller) and all the RW segments have to be 
placed in a RAM region.

Greetings,
  Martin L.


-- 
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss

Re: [ECOS] ram usage by redboot

[Gary Thomas]

Robert Brusa wrote:
> Hi all
> I have configured a redboot (using ecos-3.0) for my target. Upon power
> up it writes out (among a lot of other stuff):
> 
> Platform: AT91ICB (ARM7TDMI)
> RAM: 0x00200000-0x00220000 [0x00204c48-0x0021f300 available]
> FLASH: 0x00100000-0x0013ffff, 1024 x 0x100 blocks
> 
> This makes me wunder:
> a) What is the RAM up from 0x0021f300 used for? I can find no hint in
> the map.

It's used as an ad-hoc workspace, mostly for manipulating FLASH.  Since
the details of the FLASH device are not necessarily at compile time, this
has to be dynamic (e.g. the size of a FLASH erase page).  Carving this
off the end was the simplest way to solve these problems.

> b) It writes out the flash available on this machine. Why not the flash
> actually available for other programs?

This information is too dynamic/complex for a single print.  You get that
from 'fis free'

> Thanks for comments on this issue.
>   Robert
> 


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

-- 
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss

Re: [ECOS] ram usage by redboot

[Syed Ismail]

On Tue, 02 Jun 2009 Robert Brusa wrote :

Redboot creates two memory regions in the end of the actual flash region, fis directory-used to list partitions created in flash and redboot config-used to store boot script and other configs like mac. When redboot runs, these regions are copied to end region of ram and are not available for use.
Rgds 

--
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss