[U-Boot] arch/powerpc/lib/board.c:get_effective_memsize() for 4GB+ systems

[Kumar Gala]

On Sep 19, 2012, at 10:28 AM, Robert Thorhuus wrote:

> Hello!
> 
> I'm having problem with my U-Boot for a PowerPC system. I think the root cause is that the function get_effective_memsize() (in file arch/powerpc/lib/board.c) returns 0.
> 
> ulong get_effective_memsize(void)
> {
> #ifndef	CONFIG_VERY_BIG_RAM
> 	return gd->ram_size;
> #else
> 	/* limit stack to what we can reasonable map */
> 	return ((gd->ram_size > CONFIG_MAX_MEM_MAPPED) ?
> 		CONFIG_MAX_MEM_MAPPED : gd->ram_size);
> #endif
> }
> 
> Since the system have 24GB of RAM I have fiddled around so both CONFIG_MAX_MEM_MAPPED is actually 24GB and also gd->ram_size is 24GB.
> 
> Is it just me who have completely missed how U-Boot works or what?

What kinda of PPC system is this?

You probably don't want to change CONFIG_MAX_MEM_MAPPED.  The idea is this is how much of your 24GB is directly accessible by u-boot.  For large mem systems this is usually 2GB.

- k