From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: Linux timer interrupts not working when booting in normal-world Date: Wed, 12 Sep 2012 13:32:44 -0600 Message-ID: <5050E35C.4050105@wwwdotorg.org> References: <505095C9.5000108@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <505095C9.5000108-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Nuno Santos Cc: "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On 09/12/2012 08:01 AM, Nuno Santos wrote: > Hi > > I'm currently playing with the TrustZone technology on the Tegra2 > Harmony board, and my goal is to boot Linux not in the secure world (as > it is in mainstream Linux), but in the normal world. However, in doing > this, timer interrupts are not being triggered and the system halts > early in the bootstrap stage. ... This isn't a topic I really know anything about. I'd assume the answer to your question is ARM-generic and not Tegra-specific; you may have better luck asking on the main ARM Linux mailing list. I assume you're using (or at least can reproduce the issue with) mainline Linux, and not a downstream NVIDIA kernel? If you're using an NVIDIA kernel, I'd suggest asking your contacts at NVIDIA about it. > Assuming that this configuration is correct, one possible explanation > for the absence of timer interrupts is that the Harmony board may impose > some restrictions to the timer re-configuration in the normal world. ... I don't think the board can impose any restrictions; the boot ROM in the Tegra SoC is presumably identical across all instances of Tegra20, and the code that runs after that is whatever bootloader you built and flashed onto the board. Unless of course there are strapping/fuse options that affect this, but if any do exist, and since Harmony is a developer board, I'd imagine their settings would be left as wide open as possible. Sorry I'm not very helpful!