Hello all. I am trying to develop a proof of concept for loading a RAM based application to an RT105x via the SDP protocol. Unfortunately, I can not use the SDP protocol to write to (or read from) address 0, the first entry of my vector table containing the CSTACK address. I can only read and write from address (byte) 4 onward.
I am able to achieve what I want in an odd and indirect way:
I develop a RAM based "debug" application on IAR and generate a .bin file
I strip the first 4 bytes off of the bin file (the first entry in the vector table)
I write the file using SDP's WRITE_FILE command starting at byte 4 in memory
I connect via JTAG and write the first word of the vector table with the address of CSTACK
I execute from the reset entry point (and my app works)
I have tried SDP via the SDPhost.exe and a custom python script and the issue with address 0 exists on both. Can anyone explain what is going on here? I see no mention of this address restriction in the RT1050 reference manual or the SDPhost manual. Also, attempting to R/W address 0x0 seems to result in the SDP locking up.