From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?Andreas_Bie=DFmann?= Date: Mon, 02 Aug 2010 16:13:33 +0200 Subject: [U-Boot] [PATCH 3/3] avr32: Add simple paging support In-Reply-To: <1280750789-10359-4-git-send-email-haavard.skinnemoen@atmel.com> References: <1280750789-10359-1-git-send-email-haavard.skinnemoen@atmel.com> <1280750789-10359-4-git-send-email-haavard.skinnemoen@atmel.com> Message-ID: <4C56D28D.8010301@googlemail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Dear H?vard Skinnemoen, I have tested the simple TLB implementation on our own hardware and it does work with CFI driver. Thanks a lot for introducing this, we had to wait so long ... Am 02.08.2010 14:06, schrieb Haavard Skinnemoen: > Use the MMU hardware to set up 1:1 mappings between physical and virtual > addresses. This allows us to bypass the cache when accessing the flash > without having to do any physical-to-virtual address mapping in the CFI > driver. > > The virtual memory mappings are defined at compile time through a sorted > array of virtual memory range objects. When a TLB miss exception > happens, the exception handler does a binary search through the array > until it finds a matching entry and loads it into the TLB. The u-boot > image itself is covered by a fixed TLB entry which is never replaced. > > This makes the 'saveenv' command work again on ATNGW100 and other boards > using the CFI driver, hopefully without breaking any rules. > > Signed-off-by: Haavard Skinnemoen Tested-by: Andreas Bie?mann