[U-Boot-Users] CONFIG_MEM_INIT_VALUE == 0xDeadBeef

[Jon Loeliger]

On Tue, 2007-07-17 at 12:22, robert lazarski wrote:
> Hi all,

OK, enough of this "all" pretense! :-)  You're talking to me...

>  is this an english language pun ?
> 
> #define CONFIG_MEM_INIT_VALUE            0xDeadBeef

*sigh*  Guilty as charged, I'm afraid.

> I see that the #DEFINE is used in SPD:
> 
> cpu/mpc85xx/spd_sdram.c:      ddr->sdram_data_init = CONFIG_MEM_INIT_VALUE;
> 
> I'm porting my board which has the mpc8548e and the same exact DDR2
> that the CDS reference board has. I'm using SPD in my code. The CDS
> board has DeadBeef assigned to  CONFIG_MEM_INIT_VALUE. I don't have a
> CDS board to test. My board will arrive in a few weeks - I'm trying to
> prepare the best I can. Should I leave CONFIG_MEM_INIT_VALUE as is or
> will this make my board DeadBeef ?

The actual value is not important.  It is nominally a
non-zero, non-FF but known "poison" value.  It is merely
used to initialize memory to a known value by using the
built-in DDR controller (CONFIG_ECC_INIT_VIA_DDRCONTROLLER).
You don't have to do so if you don't want to, of course.

jdl