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1/*
2    Copyright (c) 2001-2006 by Tensilica Inc.
3
4    Permission is hereby granted, free of charge, to any person obtaining
5    a copy of this software and associated documentation files (the
6    "Software"), to deal in the Software without restriction, including
7    without limitation the rights to use, copy, modify, merge, publish,
8    distribute, sublicense, and/or sell copies of the Software, and to
9    permit persons to whom the Software is furnished to do so, subject to
10    the following conditions:
11
12    The above copyright notice and this permission notice shall be included
13    in all copies or substantial portions of the Software.
14
15    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18    IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
19    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
20    TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
21    SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22*/
23
24/*
25  This file contains a modified version of the original Xtensa longjmp implementation.
26  In this modified version, setting WINDOWSTART = 1 << WINDOWBASE is done inside a critical section.
27  This is necessary because after a FreeRTOS context switch in IDF, the values of WINDOWBASE and WINDOWSTART
28  are not guaranteed to be the same as before the context switch.
29*/
30
31#include <xtensa/corebits.h>
32
33/*
34    Replacement of the first instructions of void longjmp (jmp_buf env, int val)
35*/
36
37    .align  4
38    .literal_position
39    .global __wrap_longjmp
40    .type   __wrap_longjmp, @function
41__wrap_longjmp:
42    entry   sp, 16
43
44    /* Deactivate interrupts in order to modify WINDOWBASE and WINDOWSTART. */
45    rsr     a7, PS                     /* to be restored after SPILL_ALL_WINDOWS */
46    movi    a5, PS_EXCM                /* PS_INTLEVEL_MASK */
47    or      a5, a7, a5                 /* get the current INTLEVEL */
48    wsr     a5, PS
49
50    /* Invalidate all but the current window;
51       set WindowStart to (1 << WindowBase).  */
52    rsr a5, WINDOWBASE
53    movi    a4, 1
54    ssl a5
55    sll a4, a4
56    wsr a4, WINDOWSTART
57    rsync
58
59    /* Activate interrupts again after modifying WINDOWBASE and WINDOWSTART. */
60    wsr     a7, PS
61
62    /* Jump back to original longjmp implementation.
63        The jump target is the instrucion
64    	    l32i	a0, a2, 64
65        of the original code. Hence, the original code's entry instruction and windowstart modification are left
66        out.
67     */
68    movi a0, __real_longjmp + 20
69    jx a0
70
71    .size   __wrap_longjmp, . - __wrap_longjmp
72