- EXCEPTION(0x1800, Trap_18, UnknownException, EXC_XFER_EE)
- EXCEPTION(0x1900, Trap_19, UnknownException, EXC_XFER_EE)
- EXCEPTION(0x1A00, Trap_1A, UnknownException, EXC_XFER_EE)
- EXCEPTION(0x1B00, Trap_1B, UnknownException, EXC_XFER_EE)
- EXCEPTION(0x1C00, Trap_1C, UnknownException, EXC_XFER_EE)
- EXCEPTION(0x1D00, Trap_1D, UnknownException, EXC_XFER_EE)
- EXCEPTION(0x1E00, Trap_1E, UnknownException, EXC_XFER_EE)
- EXCEPTION(0x1F00, Trap_1F, UnknownException, EXC_XFER_EE)
-
-/* 0x2000 - Debug Exception
-*/
+ EXCEPTION(0x1800, Trap_18, unknown_exception, EXC_XFER_EE)
+ EXCEPTION(0x1900, Trap_19, unknown_exception, EXC_XFER_EE)
+ EXCEPTION(0x1A00, Trap_1A, unknown_exception, EXC_XFER_EE)
+ EXCEPTION(0x1B00, Trap_1B, unknown_exception, EXC_XFER_EE)
+ EXCEPTION(0x1C00, Trap_1C, unknown_exception, EXC_XFER_EE)
+ EXCEPTION(0x1D00, Trap_1D, unknown_exception, EXC_XFER_EE)
+ EXCEPTION(0x1E00, Trap_1E, unknown_exception, EXC_XFER_EE)
+ EXCEPTION(0x1F00, Trap_1F, unknown_exception, EXC_XFER_EE)
+
+/* Check for a single step debug exception while in an exception
+ * handler before state has been saved. This is to catch the case
+ * where an instruction that we are trying to single step causes
+ * an exception (eg ITLB/DTLB miss) and thus the first instruction of
+ * the exception handler generates a single step debug exception.
+ *
+ * If we get a debug trap on the first instruction of an exception handler,
+ * we reset the MSR_DE in the _exception handler's_ MSR (the debug trap is
+ * a critical exception, so we are using SPRN_CSRR1 to manipulate the MSR).
+ * The exception handler was handling a non-critical interrupt, so it will
+ * save (and later restore) the MSR via SPRN_SRR1, which will still have
+ * the MSR_DE bit set.
+ */
+ /* 0x2000 - Debug Exception */