From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Jin Date: Fri, 25 Feb 2005 14:56:17 -0800 Subject: [U-Boot-Users] set up stack before board_init_f() on ppc440 core? In-Reply-To: <20050225214603.27978C1430@atlas.denx.de> References: <20050225214603.27978C1430@atlas.denx.de> 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 Dear Wolfgang, > Which part of section "Initial Stack, Global Data" in the README > don't you understand? Thanks for pointing out the section. I didn't read it through before. :( > > stack in DCACHE (Walnut 405 is an example). But the CFG_INIT_RAM_ADDR > > is 0x40000000, which is inside SDRAM. Why was it commented that the > > No, this is not inside SDRAM. There is no board (yet) with 1 GB of > RAM. Well, "inside SDRAM" is what is commented on WALNUT.h. Now I understand the value of CFG_INIT_RAM_ADDR is better not to interfere with the system design. > In short: cache is like normal memory, just very fast (which does not > play a role here). We just have to make sure that no cache fills or > cache flushes will be done (at least not for that part of the data > cache which is being used for the initial stack). I don't see any caches are in a system memory mapping. Then I thought it could be only accessed by those cache specific instructions, like dcread. That's my misunderstanding. Thanks, -Shawn.