From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Date: Mon, 19 Jan 2015 15:57:24 -0700 Subject: [U-Boot] [PATCH 1/3] common: board: support systems with where RAM ends beyond 4GB In-Reply-To: <1419356091-13121-1-git-send-email-swarren@wwwdotorg.org> References: <1419356091-13121-1-git-send-email-swarren@wwwdotorg.org> Message-ID: <54BD8BD4.2030908@wwwdotorg.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 12/23/2014 10:34 AM, Stephen Warren wrote: > From: Stephen Warren > > Some systems have so much RAM that the end of RAM is beyond 4GB. An > example would be a Tegra124 system (where RAM starts at 2GB physical) > that has more than 2GB of RAM. > > In this case, we can gd->ram_size to represent the actual RAM size, so > that the actual RAM size is passed to the OS. This is useful if the OS > implements LPAE, and can actually use the "extra" RAM. > > However, U-Boot does not implement LPAE and so must deal with 32-bit > physical addresses. To this end, we enhance board_get_usable_ram_top() to > detect the "over-sized" case, and limit the relocation addres so that it > fits into 32-bits of physical address space. TomW, TomR, does this series look good?