// Copyright 2015-2017 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at

//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.


#include <xtensa/coreasm.h>
#include <xtensa/corebits.h>
#include <xtensa/config/system.h>
#include <xtensa/simcall.h>
#include "freertos/xtensa_context.h"
#include "esp_panic.h"
#include "sdkconfig.h"
#include "soc/soc.h"



/*
In some situations, the panic handler needs to be invoked even when (low/medium priority) interrupts
are disabled. In that case, we use a high interrupt to panic anyway. This is the high-level interrupt
handler for such a situation. We use interrupt level 4 for this.
*/

    .section .iram1,"ax"
    .global     xt_highint4
    .type       xt_highint4,@function
    .align      4
xt_highint4:


    /* On the ESP32, this level is used for panic events that are detected by hardware and should 
       also panic when interrupts are disabled. At the moment, these are the interrupt watchdog
       as well as the cache invalid access interrupt. (24 and 25) */

    /* Allocate exception frame and save minimal context. */
    mov     a0, sp
    addi    sp, sp, -XT_STK_FRMSZ
    s32i    a0, sp, XT_STK_A1
    #if XCHAL_HAVE_WINDOWED
    s32e    a0, sp, -12                     /* for debug backtrace */
    #endif
    rsr     a0, PS                          /* save interruptee's PS */
    s32i    a0, sp, XT_STK_PS
    rsr     a0, EPC_4                       /* save interruptee's PC */
    s32i    a0, sp, XT_STK_PC
    #if XCHAL_HAVE_WINDOWED
    s32e    a0, sp, -16                     /* for debug backtrace */
    #endif
    s32i    a12, sp, XT_STK_A12             /* _xt_context_save requires A12- */
    s32i    a13, sp, XT_STK_A13             /* A13 to have already been saved */
    call0   _xt_context_save

    /* Save vaddr into exception frame */
    rsr     a0, EXCVADDR
    s32i    a0, sp, XT_STK_EXCVADDR

    /* Figure out reason, save into EXCCAUSE reg */

    rsr     a0, INTERRUPT
    extui   a0, a0, ETS_CACHEERR_INUM, 1 /* get cacheerr int bit */
    beqz    a0, 1f
    /* Kill this interrupt; we cannot reset it. */
    rsr     a0, INTENABLE
    movi    a4, ~(1<<ETS_CACHEERR_INUM)
    and     a0, a4, a0
    wsr     a0, INTENABLE
    movi    a0, PANIC_RSN_CACHEERR
    j 9f
1:
#if CONFIG_INT_WDT_CHECK_CPU1
    /* Check if the cause is the app cpu failing to tick.*/
    movi    a0, int_wdt_app_cpu_ticked
    l32i    a0, a0, 0
    bnez    a0, 2f
    /* It is. Modify cause. */
    movi    a0,PANIC_RSN_INTWDT_CPU1
    j 9f
2:
#endif
    /* Set EXCCAUSE to reflect cause of the wdt int trigger */
    movi    a0,PANIC_RSN_INTWDT_CPU0
9:
    /* Found the reason, now save it. */
    s32i    a0, sp, XT_STK_EXCCAUSE

    /* _xt_context_save seems to save the current a0, but we need the interuptees a0. Fix this. */
    rsr     a0, EXCSAVE_4                   /* save interruptee's a0 */

    s32i    a0, sp, XT_STK_A0

    /* Set up PS for C, disable all interrupts except NMI and debug, and clear EXCM. */
    movi    a0, PS_INTLEVEL(5) | PS_UM | PS_WOE
    wsr     a0, PS

    //Call panic handler
    mov     a6,sp
    call4   panicHandler

    call0   _xt_context_restore
    l32i    a0, sp, XT_STK_PS               /* retrieve interruptee's PS */
    wsr     a0, PS
    l32i    a0, sp, XT_STK_PC               /* retrieve interruptee's PC */
    wsr     a0, EPC_4
    l32i    a0, sp, XT_STK_A0               /* retrieve interruptee's A0 */
    l32i    sp, sp, XT_STK_A1               /* remove exception frame */
    rsync                                   /* ensure PS and EPC written */

    rsr     a0, EXCSAVE_4                   /* restore a0 */
    rfi     4



/* The linker has no reason to link in this file; all symbols it exports are already defined
   (weakly!) in the default int handler. Define a symbol here so we can use it to have the 
   linker inspect this anyway. */

    .global ld_include_panic_highint_hdl
ld_include_panic_highint_hdl: