On 2015-02-16 14:49, Mark Rutland wrote: > On Mon, Feb 16, 2015 at 12:54:48PM +0000, Jan Kiszka wrote: >> From: Ian Campbell <i...@hellion.org.uk> >> >> These registers can be used to prevent non-secure world from accessing a >> megabyte aligned region of RAM, use them to protect the u-boot secure monitor >> code. > > What happens if the CPU tried to read this memory from the non-secure > world? If the OS has it mapped then the CPU could perform speculative > reads at any point in time. > > If that can raise an abort then the OS needs to not map the region. > > I take it U-Boot uses a secure mapping for the region (which I believe > should avoid the mismatched attributes issue I mentioned in my other > reply).
What I can contribute to this are kernel messages due to a misconfiguration of our hypervisor Jailhouse (while Linux was still trying to boot it): [ 61.896860] tegra-mc 70019000.memory-controller: mpcorew: write @0x00000000fff00040: Security violation (TrustZone violation) [ 61.896888] tegra-mc 70019000.memory-controller: mpcorew: write @0x00000000fff2d340: Security violation (TrustZone violation) So it seems that Linux is receiving a violation report here when trying to access the memory. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
