From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Date: Wed, 05 Aug 2015 13:27:00 -0600 Subject: [U-Boot] [PATCH] ARM: tegra: restrict usable RAM size further In-Reply-To: <82336276bf4c4920b74974124cac06f0@HQMAIL104.nvidia.com> References: <1438199278-29247-1-git-send-email-swarren@wwwdotorg.org> <55C256E0.6010708@wwwdotorg.org> <82336276bf4c4920b74974124cac06f0@HQMAIL104.nvidia.com> Message-ID: <55C26384.7020506@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 08/05/2015 01:22 PM, Tom Warren wrote: >> -----Original Message----- >> From: Stephen Warren [mailto:swarren at wwwdotorg.org] >> Sent: Wednesday, August 05, 2015 11:33 AM >> To: Tom Warren >> Cc: u-boot at lists.denx.de; Simon Glass; Stephen Warren; Thierry Reding >> Subject: Re: [U-Boot] [PATCH] ARM: tegra: restrict usable RAM size further >> >> On 07/29/2015 01:47 PM, Stephen Warren wrote: >>> From: Stephen Warren >>> >>> Additionally, ARM64 devices typically run a secure monitor in EL3 and >>> U-Boot in EL2, and set up some secure RAM carve-outs to contain the >>> EL3 code and data. These carve-outs are located at the top of 32-bit >>> address space. Restrict U-Boot's RAM usage to well below the location >>> of those carve-outs. Ideally, we would the secure monitor would inform >>> U-Boot of exactly which RAM it could use at run-time. However, I'm not >>> sure how to do that at present (and even if such a mechanism does >>> exist, it would likely not be generic across all forms of secure monitor). >> >> TomW, what are your thoughts on applying this given the discussion thread? >> Thanks. > > I think this patch is fine. I have not set up any TZ/other carveouts (NVDEC,VPR,GPU,TSEC, etc.) yet in U-Boot, but I have in coreboot, and right now we're using approx. 153MB (0xf66c0000 - 0x100000000). So 512MB here seems large but OK, given that we'll still have tons of SDRAM left on most any modern board. > > I can take this in on the next pass, if no one objects. Adding Marcel for Colibri T20/T30, since this'll affect those boards, too. Thanks. This should only affect Tegra210 boards, since the function I modified is under #ifdef CONFIG_ARM64.