| // exc-unhandled.S - General Exception Handler for unhandled exceptions |
| |
| // Copyright (c) 2002-2004, 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/corebits.h> |
| #include "xtos-internal.h" |
| #ifdef SIMULATOR |
| #include <xtensa/simcall.h> |
| #endif |
| |
| #if XCHAL_HAVE_EXCEPTIONS |
| |
| /* |
| * Assembly-level exception handler used when no handler was |
| * registered for the specific exception cause. |
| * |
| * The BREAK instruction is used to give control to the debugger, |
| * if one is present and active. (If none is present and active, |
| * the default debug exception handler will typically skip over |
| * this break instruction.) |
| * This code follows the convention documented in the ISA manual |
| * to use BREAK instructions to signal unhandled exceptions to the |
| * debugger. For the debugger to report or handle this condition |
| * in an OS-independent manner, all processor state (except PC) |
| * must be restored as it was when the unhandled exception just |
| * occurred (ie. as it was at the beginning of the vector). |
| * If execution continues after the BREAK instruction (in which |
| * case any register might have been modified by the debugger), |
| * just return. |
| */ |
| .text |
| .align 4 |
| |
| // If not pulled-in some other way, define it as unhandled: |
| .weak xtos_cause3_handler |
| .global xtos_cause3_handler |
| xtos_cause3_handler: |
| |
| .global xtos_unhandled_exception |
| xtos_unhandled_exception: |
| #if XCHAL_HAVE_DEBUG || defined(SIMULATOR) |
| l32i a2, a1, UEXC_a2 // restore a2 |
| l32i a3, a1, UEXC_a3 // restore a3 |
| // Note: a4-a5 not clobbered, no need to restore. |
| addi a1, a1, ESF_TOTALSIZE // restore sp |
| # if XCHAL_HAVE_DEBUG |
| break 1, 1 // give control to the debugger (if any present) |
| # else |
| wsr.excsave1 a2 // save a2 where simulator expects it |
| movi a2, SYS_unhandled_user_exc |
| simcall // let simulator/debugger report unhandled exception |
| rsr.excsave1 a2 // restore a2 |
| # endif |
| rfe_rfue // if sim/debug resume, just return |
| #else /* DEBUG or SIMULATOR */ |
| j xtos_unhandled_exception // just loop forever |
| #endif /* DEBUG or SIMULATOR */ |
| |
| .size xtos_unhandled_exception, . - xtos_unhandled_exception |
| |
| |
| #endif /* XCHAL_HAVE_EXCEPTIONS */ |
| |
