Messages in this thread | | | Subject | Re: [PATCH] arm: Handle starting up in secure mode | From | Daniel Thompson <> | Date | Thu, 27 Aug 2015 17:17:11 +0100 |
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On 24/08/15 14:55, Christopher Covington wrote: > ARM Linux appears to have never been made aware of the ARMv7 security > extensions. When CONFIG_ARM_SEC_EXT=y, have it probe for its security > state by checking whether CNTFRQ is writeable and potentially make > mode changes based on the information. The most features are available > from hypervisor (HYP) mode, so switch to it possible. Failing that, > prefer non-secure supervisor (SVC) mode to secure supervisor mode.
If there is no hypervisor mode available what benefit do we get from transitioning to non-secure mode?
When running in secure mode we retain access to some potentially useful features such as having access to FIQ.
Daniel.
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