From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Date: Fri, 16 Jan 2015 09:52:25 +0100 Subject: [U-Boot] [PATCH v1 3/4] jetson-tk1: Add PSCI configuration options and reserve secure code In-Reply-To: <54B85450.1030504@wwwdotorg.org> References: <1421178290.11796.159.camel@hellion.org.uk> <1421178360-23778-3-git-send-email-ijc@hellion.org.uk> <54B85450.1030504@wwwdotorg.org> Message-ID: <20150116085224.GA9170@ulmo.nvidia.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Thu, Jan 15, 2015 at 04:59:12PM -0700, Stephen Warren wrote: > On 01/13/2015 12:45 PM, Ian Campbell wrote: > >The secure world code is relocated to the MB just below the top of 4G, we > >reserve it in the FDT (by setting CONFIG_ARMV7_SECURE_RESERVE_SIZE) but it is > >not protected in h/w. See next patch. > > >diff --git a/include/configs/jetson-tk1.h b/include/configs/jetson-tk1.h > > >+#define CONFIG_ARMV7_PSCI 1 > >+/* Reserve top 1M for secure RAM */ > >+#define CONFIG_ARMV7_SECURE_BASE 0xfff00000 > >+#define CONFIG_ARMV7_SECURE_RESERVE_SIZE 0x00100000 > > I /think/ the assumption in the existing code is that > CONFIG_ARMV7_SECURE_BASE is the base of some out-of-DRAM secure memory, and > hence that's why arch/arm/cpu/armv7/virt-dt.c() only reserves memory if that > symbol is *not* set? That seems like rather a confusing semantic given the > variable name. Introducing a new define that looks like it's simply the size > of that region but actually changes the reservation semantics makes the > situation worse for me. > > Wouldn't it be better to have: > > CONFIG_ARMV7_SECURE_BASE defines where the secure code is copied to. > > CONFIG_ARMV7_SECURE_BASE_IS_IN_DRAM defines the obvious; whether the secure > base is in DRAM or not. > > That define would default to unset and you'd get the current behaviour. > > If that define was set, then CONFIG_ARMV7_SECURE_BASE through > CONFIG_ARMV7_SECURE_BASE + (__secure_end - __secure_start) would be reserved > in RAM? > > That way, armv7_update_dt would be more like: > > int armv7_update_dt(void *fdt) > { > #if defined(CONFIG_ARMV7_SECURE_BASE_IS_IN_DRAM) || \ > !defined(CONFIG_ARMV7_SECURE_BASE) > /* secure code lives in RAM, keep it alive */ > #if defined(CONFIG_ARMV7_SECURE_BASE) > base = CONFIG_ARMV7_SECURE_BASE; > #else > base = __secure_start; > #endif > fdt_add_mem_rsv(fdt, base, __secure_end - __secure_start); > #endif > > return fdt_psci(fdt); > } As I understand it, one of the purposes of the RESERVE_SIZE is that hardware may not allow regions of arbitrary size to be reserved. On Tegra for example I think the restriction is that memory can only be secured on 1 MiB boundaries. So unless explicitly specified we'd need a way for platforms to be able to adjust the reserved region accordingly. Thierry -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 819 bytes Desc: not available URL: