Re: Writing to UART mapped memory address

In base-hw/src/core/spec/arm_v7/trustzone/mode_transition.s, _nonsecure_kernel_entry:, where we go in the monitor handler after a DABT, we have mov r1, #0 mcr p15, 0, r1, c1, c1, 0 //sets SCR all 0s cps #SVC_MODE //changes processor mode to SVC

In base-hw/src/core/spec/arm_v7/trustzone/kernel/vm.cc, in void Vm::exception(unsigned const cpu), case Genode::Cpu_state::DATA_ABORT:, Cpu::Scr::read() gives 00000000 and Cpu::Psr::read() gives 600001d3. So the NS bit in Scr is 0 and the mode bits in CPSR are 10011=19, which is the SVC mode. So we are getting the correct values that the monitor DABT handler sets.

We are in the secure SVC mode, when we try to access the uart physical address. So what is causing a data abort now?

Thanks! Riju