I am running on Cortex-R82 FVP.
EL2: MPU disabled with background region also disabled. EL1: MPU enabled with multiple non-overlapping regions, background region disabled.
SCTLR_EL[2|1].WXN is set to 0.
Behavior: In EL1, when I write to a normal memory MPU region that has write and execute permissions enabled (around memory location 0x86400, if it matters), the write operation causes a fault. The issue disappears when the region is marked non-executable (prbar.XN bit is set).
My question is, if this is expected behavior or if it is an FVP parameter/bug? If it is expected, would be grateful if I could be pointed to the documentation that explains it further.
This is the issue, the Aarch64 memory model mentions: "A location with EL0 write permissions is never executable at EL1."
Thanks for the hint!