Is ARM (not Thumb) supported on WinPhone8 at all?

Question

I\'m facing a weird issue, somewhat similar to this. I have a Windows Phone 8 native DLL project, mostly C++ but with an ARM assembly source in it. The source is in ARM mode

Answer 1

A gentleman called Michael Schnell suggested elsewhere that the interrupt handler in Windows Phone 8 doesn't restore the Thumb flag, instead hard-codes it to 1. Testing seems to confirm that theory. The following snippet:

    THUMB
ASMTest
    mov r12, lr
    blx a
    mov lr, r12
    bx lr

    ALIGN 4
    ARM
a
    bx lr

consistently crashes under a debugger, but runs as expected when debuggerless (i. e. no interrupts while in ARM mode). When I inserted an empty loop with 0x10000 iterations in ARM mode, it ran on a few tries, then crashed.