RE: [ECOS] ARM AEB-1 Rev C Memory Usage

[Gary Thomas <gthomas at cygnus dot co dot uk>]

On 06-Dec-99 Srdjan Sobajic wrote:
> Hi,
> 
> This is probably a very elementary question, however, I can't seem to find
> out what I need
> through the docs on the Web.
> 
> I have the ARM AEB-1C board here and I've been playing with eCos (from the
> CVS tree) on it.
> As far as I can tell, there are two places where the memory map is defined
> for the 
> AEB-1C target: ie.
> ecos-1.2.1/packages/hal/arm/aeb/current/include/hal_platform_setup.h and
> ecos-1.2.1/packages/hal/arm/arch/current/src/arm.ld
> 
> It is my impression that these files are mostly responsible for the
> generation of the 
> various mlt_arm_aebC*.* files. 
> 
> Looking through the mlt* files, first I am curious about the fact that the
> size of the RAM is 
> described as 0x48000 when in fact it is 0x40000. Where does the extra 32 k
> come from?
> 

This is because the memory is mapped (using the hardware registers) from
  0x8000 .. 0x48000

> My real question is, however, how do I access all the memory available on
> the board? 
> I can't seem to access any memory above 0x20000... (I've never seen anything
> above that
> address running in the debugger, and malloc() fails to get memory even
> though it should be free...)
> 
> Do I have to use to cyg_mempool* commands to use this or am I doing
> something fundamentally 
> wrong?
> 

Currently, malloc() takes it's memory from a hard-coded pool.  In the future
it may use all available memory, but for the current time, you'll need to
modify your configuration to get this memory.

Change this line in <pkgconf/libc.h>

  #define CYGNUM_LIBC_MALLOC_MEMPOOL_SIZE 16384

See if this helps with your malloc() problems.