Messages in this thread | | | Date | Fri, 1 Aug 2014 19:04:11 +0200 | From | Robert Richter <> | Subject | Re: [PATCH 2/5] arm64, thunder: Add initial dts for Cavium Thunder SoC |
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Mark,
On 31.07.14 12:33:01, Mark Rutland wrote: > On Thu, Jul 31, 2014 at 12:12:33PM +0100, Ganapatrao Kulkarni wrote: > > We mark RAM used by ATF as secure-RAM, however we don't support > > secure/non-secure address aliasing. > > i.e, a DRAM address that can be referenced from both a secure PA and a > > non-secure PA is not allowed. > > What exactly do you mean by "not allowed"?
It actually means "not possible" since secure and non-secure memory is kept in separate address ranges.
> If Linux maps that memory, what happens? > > What if Linux tried to read or write to it? > > If Linux should not map that memory, it should not be described in the > memory map to begin with.
Linux never will see secure-RAM. Firmware must be sure to report the correct non-secure memory ranges to the OS (e.g. unsecure mem size = total size - secure mem size).
-Robert
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