Segger J-Link GDB-Server / STM32100B-EVAL / Debugging hangs at first instruction
The reason is most likely that the instruction you are trying to step is
an endless loop, as typically used with an RTOS in the idle loop.
Eclipse is now seeing that that the PC has not changed and tries again.
Remedy: Check what the instruction is; if this is so, add a nop to the loop.
With SEGGER's J-Link, you may as well use other free GDB tool chains such
emide or em::Blocks.