my goal is to setup an apalis imx6 chip with our secure OS in the Trustzone, and a modified Linux running in the normal world. Each time I switch from Linux to the secure OS, an asynchronous external abort arise. In order to debug this, I wanted to force EA to the monitor, by setting SCR.AW to 0 (NW can’t modifiy the CPSR.A bit) and SCR.EA to 1 (branch to Monitor on EA).
Even in this configuration (which works on other imx6 boards we have, like NXP Sabre or Boundary Devices Sabre lite), Linux can still set CPSR.A to 1 and the abort does not goes to the monitor.
In order to debug the situation, I had to patch linux and explicitely remove the CPSR.A bit. With this patch, I get the EA more quickly (and it seems the PCIe drivers is making some secure access I will need to fix).
I wanted to know if this behavior was known and / or normal, and if I needed to notify you or NXP ?