Move ebreak* logic from take_trap into instructions. (#1006)

Now that logic only affects ebreak instructions, and does not affect
triggers that also cause a trap to be taken.

Fixes #725. Although like Paul, I don't have a test for this case.

Introduce trap_debug_mode so so ebreak instructions can force entry into
debug mode.

1 files changed, 4 insertions, 0 deletions

diff --git a/riscv/execute.cc b/riscv/execute.cc
index a6ea7a4..ea4dc5b 100644
--- a/riscv/execute.cc
+++ b/riscv/execute.cc
@@ -337,6 +337,10 @@ void processor_t::step(size_t n)
           abort();
       }
     }
+    catch(trap_debug_mode&)
+    {
+      enter_debug_mode(DCSR_CAUSE_SWBP);
+    }
     catch (wait_for_interrupt_t &t)
     {
       // Return to the outer simulation loop, which gives other devices/harts a