We use P2.1/P2.2 as GPIO, no physical external memory is connected to the chip. When power on, before executing the first line of code in main(), we observed a glitch occurred in these two pins. This is not allowed in our system because it will damage the parts connected to it. The glitches happened when we declare __xdata variables, i.e., using XRAM. If we don't declare __xdata variables, glitches will not happen. I found that there is a Xdata initialization_to_zero routine in the cstartup code, so maybe this results in the glitch on P2.0/2.1.
How can we remove this xdata initialization section?