ecall module now kills processes which trigger an exception

kinclude/ecall.c

@@ -202,7 +202,12 @@ void init_ecall_table()
 
 void handle_exception(int ecode, int mtval)
 {
-    //TODO: handle exceptions well
-    dbgln("exception encountered!", 17);
-    __asm__ ("ebreak");
+    // kill off offending process
+    ProcessControlBlock* pcb = get_current_process();
+    pcb->status = PROC_DEAD;
+    pcb->exit_code = -99;
+    destroy_process(pcb);
+
+    // run the next process
+    scheduler_run_next();
 }

kinclude/sched.c

@@ -96,7 +96,7 @@ ProcessControlBlock* scheduler_select_free()
                     pcb->waiting_for_process->status == PROC_DEAD) {
                     // the requested process exited, so we can set the status code and
                     pcb->regs[REG_A0] = pcb->waiting_for_process->exit_code;
-                    pcb->regs[REG_A0+1] = 0;
+                    pcb->regs[REG_A0 + 1] = 0;
                     pcb->status = PROC_RDY;
                     return pcb;
                 }