Based on a job at my workplace that could be available for your students, this is practical: Make them use a JTAG debugger such as the Ronetix PEEDI. Make them

Based on a job at my workplace that could be available for your students, this is practical: Make them use a JTAG debugger such as the Ronetix PEEDI. Make them debug timing-sensitive boot code, such as SDRAM detection routines that use GPIO pins to bit-bang SMBus protocol to the SPD EEPROM. Have a hardware watchdog enabled when this code is hit; it should reset the CPU after a few seconds. Another suggestion is to use the debugger that is included with IDA Pro. Make them connect IDA Pro to a remote system, then debug a kernel driver without source code. The "trace replay" capability may come in handy.