From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Gehrlein Date: Fri, 16 Nov 2007 14:29:56 +0100 Subject: [U-Boot-Users] post memory test In-Reply-To: References: Message-ID: <473D9B54.1010304@tqs.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Detlev Zundel wrote: > Hi Dongy, > >> I have a question about post memory test. According to the following code, even >> if memory size is greater than 256M, only 256M memory will be tested. Is it >> true or I missed something. Thanks a lot. > > No, this is true. As I did not write that code, my interpretation > uses some speculation, but what is very likely the case here is that > U-Boot potentially does not map all physical available memory and thus > we cannot even access it. As we do not have explicit variables > representing those facts, I guess the 256MB are kind of a least > common denominator. > > As an example look at initdram() in board/Marvell/db64460/sdram_init.c > where the platform uses Block Address Translations (BATs) to map RAM > but exhausts these pretty scarce ressources and limits itself to > mapping only the first 256MB (a usual limit for a BAT). So it is possible to overlay the function memory_post_test() by a board specific routine, which may cover almost all RAM? BTW, is it possible to overlay _all_ POST routines by board specific routines? Kind regards Jens