Interactive debug tool.

    - Modify debug fw to support writing data.
    - Modify debug fw to support clocking model forward.
    - Add simics environment support for both.
    - Kernel support to start a task when directed.
    - Write debug tool to modify kernel structure for debug.

Change-Id: Ic001dfd45f91392aefbc9d5096c5344018d5190e
Reviewed-on: http://gfw160.austin.ibm.com:8080/gerrit/518
Tested-by: Jenkins Server
Reviewed-by: Andrew J. Geissler <andrewg@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>
Reviewed-by: A. Patrick Williams III <iawillia@us.ibm.com>

1 files changed, 89 insertions, 0 deletions

diff --git a/src/kernel/idebug.C b/src/kernel/idebug.C
new file mode 100644
index 000000000..673ecb149
--- /dev/null
+++ b/src/kernel/idebug.C
@@ -0,0 +1,89 @@
+//  IBM_PROLOG_BEGIN_TAG
+//  This is an automatically generated prolog.
+//
+//  $Source: src/kernel/idebug.C $
+//
+//  IBM CONFIDENTIAL
+//
+//  COPYRIGHT International Business Machines Corp. 2011
+//
+//  p1
+//
+//  Object Code Only (OCO) source materials
+//  Licensed Internal Code Source Materials
+//  IBM HostBoot Licensed Internal Code
+//
+//  The source code for this program is not published or other-
+//  wise divested of its trade secrets, irrespective of what has
+//  been deposited with the U.S. Copyright Office.
+//
+//  Origin: 30
+//
+//  IBM_PROLOG_END
+#include <kernel/idebug.H>
+#include <kernel/console.H>
+#include <kernel/cpumgr.H>
+#include <kernel/scheduler.H>
+#include <sys/task.h>
+
+    // Set Ready = 0, Running = 1, Complete = 0.
+static const uint64_t IDEBUG_RUNNING_STATE  = 0x0001000000000000ull;
+    // Set Ready = 0, Running = 0, Complete = 1.
+static const uint64_t IDEBUG_COMPLETE_STATE = 0x0000010000000000ull;
+
+void InteractiveDebug::startDebugTask()
+{
+    // Atomically set state to 'running'.
+    // Set Ready = 0, Running = 1, Complete = 0.
+    __sync_lock_test_and_set(&state_value, IDEBUG_RUNNING_STATE);
+
+    // Create userspace task to execute function.
+    task_t* t = TaskManager::createTask(&debugEntryPoint, this, true);
+    CpuManager::getCurrentCPU()->scheduler->addTask(t);
+
+    return;
+}
+
+void InteractiveDebug::debugEntryPoint(void* i_idObject)
+{
+    // Detach task so it is cleaned up properly once it exits.
+    task_detach();
+
+    // Get interactive debug structure from cast of input paramater.
+    InteractiveDebug* interactiveDebug =
+        static_cast<InteractiveDebug*>(i_idObject);
+
+    // Get function pointer from 'entry_point_toc'.
+    typedef uint64_t(*func)(uint64_t,uint64_t,uint64_t,uint64_t,
+                            uint64_t,uint64_t,uint64_t,uint64_t);
+    func entry_point =
+            reinterpret_cast<func>(interactiveDebug->entry_point_toc);
+
+    // Call function with parameters.
+    //     Due to the PowerABI, parameters get passed in r3-r10 and any
+    //     unused parameters are ignored by the called function.  You can
+    //     therefore treat every function as if it has 8 parameters, even
+    //     if it has fewer, and the calling conventions are the same from
+    //     an assembly perspective.
+    interactiveDebug->return_value =
+            entry_point(interactiveDebug->parms[0],
+                        interactiveDebug->parms[1],
+                        interactiveDebug->parms[2],
+                        interactiveDebug->parms[3],
+                        interactiveDebug->parms[4],
+                        interactiveDebug->parms[5],
+                        interactiveDebug->parms[6],
+                        interactiveDebug->parms[7]);
+
+    // Atomically set state to 'complete'.
+    //     This must be proceeded by a sync to ensure all memory operations
+    //     and instructions have fully completed prior to setting the complete
+    //     state (due to weak consistency).
+    // Set Ready = 0, Running = 0, Complete = 1.
+    __sync_synchronize();
+    __sync_lock_test_and_set(&interactiveDebug->state_value,
+                             IDEBUG_COMPLETE_STATE);
+
+    task_end();
+}
+