From mboxrd@z Thu Jan 1 00:00:00 1970 From: Detlev Zundel Date: Fri, 23 May 2008 16:49:34 +0200 Subject: [U-Boot-Users] Can CPU write video memory directly? In-Reply-To: <17340898.post@talk.nabble.com> (zhanglei's message of "Tue, 20 May 2008 06:54:14 -0700 (PDT)") References: <17340898.post@talk.nabble.com> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Zhanglei459, > Now I am debugging video chip MB86297A.Reference to hardware manual,I > have configured PCI registers ,Carmine Control registers and DRAM Control > registers under U-boot , other modules registers have not been configured.I > dont know how to verify DRAM is configured correctly. When I "md" video > memory,they are all zero,and after I "mm" video memory,they are "md" still > display all zero . Something must be wrong in your configuration. I recently did a standard "mtest" on a CoralP attached graphics memory *after* correctly setting up the CoralP control registers. Note that I had to setup CCF and MMR registers correctly (swapping endinanness by hand!). > Are DRAM Control registers configured wrong? Most likely. > Does CPU modify video memory? No, why should it? Cheers Detlev -- five monkeys, two typewriters, ten minutes -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu at denx.de