move sboot to the root directory

[open-ath9k-htc-firmware.git] / sboot / magpie_1_1 / sboot / athos / src / xtos / double-vector.S

diff --git a/sboot/magpie_1_1/sboot/athos/src/xtos/double-vector.S b/sboot/magpie_1_1/sboot/athos/src/xtos/double-vector.S
new file mode 100755 (executable)
index 0000000..ad96144
--- /dev/null
+++ b/sboot/magpie_1_1/sboot/athos/src/xtos/double-vector.S
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+// double-vector.S  --  Double Exception Vector
+// $Id: //depot/rel/Cottonwood/Xtensa/OS/xtos/double-vector.S#3 $
+
+// Copyright (c) 2000-2004, 2006, 2010 Tensilica Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining
+// a copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to
+// permit persons to whom the Software is furnished to do so, subject to
+// the following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+#include <xtensa/coreasm.h>
+#include <xtensa/config/system.h>
+#include <xtensa/config/specreg.h>
+#ifdef SIMULATOR
+#include <xtensa/simcall.h>
+#endif
+
+
+#if XCHAL_HAVE_EXCEPTIONS && defined(XCHAL_DOUBLEEXC_VECTOR_VADDR)
+
+/*
+ *  This is a very minimalist implementation of the double
+ *  exception vector.  For XEA2 configurations without a
+ *  full MMU, this vector is only expected to be executed
+ *  upon fatal errors (exceptions that occur within critical
+ *  sections of exception vectors and handlers).
+ *
+ *  For configurations with a full MMU (ie. with TLBs and
+ *  auto-refill) and the windowed address registers option,
+ *  a more complete version of this handler is necessary if:
+ *  dynamic page mapping is implemented, and the stack
+ *  can ever point to a dynamically mapped area.
+ *  In this case, a double exception is a normal occurrence
+ *  when a stack access within a window handler causes
+ *  a TLB miss exception or other expected MMU fault.
+ *  XTOS does not support this scenario, hence a minimalist
+ *  double exception vector is sufficient.
+ */
+
+       .begin  literal_prefix  .DoubleExceptionVector
+       .section                .DoubleExceptionVector.text, "ax"
+
+       .align 4
+       .global _DoubleExceptionVector
+_DoubleExceptionVector:
+#  if XCHAL_HAVE_DEBUG
+1:     break   1,4                     // unhandled double exception
+#  elif defined(SIMULATOR)
+       wsr     a2, EXCSAVE1            // save a2 where simulator expects it
+       movi    a2, SYS_unhandled_double_exc
+1:     simcall                         // let simulator/debugger report unhandled exception
+#  else
+1:
+#  endif
+       j       1b                      // infinite loop
+
+       // NOTE:  a non-minimalist vector may choose to
+       // process the double exception in the vector itself
+       // (by default, much more space is allocated to double
+       // exception vectors than to most other vectors);
+       // or, to jump to a double exception handler located
+       // elsewhere.  If only the normal case of double
+       // exceptions occurring within a window handler is
+       // being handled, then it is safe to use EXCSAVE_1 to
+       // do this jump (window handlers don't use EXCSAVE_1).
+       // For example:
+       //
+       //      wsr     a0, EXCSAVE_1
+       //      movi    a0, _DoubleExceptionFromVector
+       //      jx      a0
+       //
+       //      .text
+       //      .align  4
+       //      .global _DoubleExceptionFromVector
+       //_DoubleExceptionFromVector:
+       //      ...
+
+
+       .size   _DoubleExceptionVector, . - _DoubleExceptionVector
+       .text
+       .end    literal_prefix
+
+#endif /* have double exceptions */
+