/*
    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
                 2011 Giovanni Di Sirio.

    This file is part of ChibiOS/RT.

    ChibiOS/RT is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    ChibiOS/RT is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

        MODULE  ?chcoreasm_v7m

        AAPCS INTERWORK, VFP_COMPATIBLE
        PRESERVE8

/*
 * Imports the Cortex-Mx configuration headers.
 */
#define _FROM_ASM_
#include "chconf.h"
#include "chcore.h"

CONTEXT_OFFSET  SET 12
SCB_ICSR        SET 0xE000ED04
ICSR_PENDSVSET  SET 0x10000000

        SECTION .text:CODE:NOROOT(2)

        EXTERN  chThdExit
        EXTERN  chSchDoReschedule
#if CH_DBG_SYSTEM_STATE_CHECK
        EXTERN  dbg_check_unlock
        EXTERN  dbg_check_lock
#endif

        THUMB

/*
 * Performs a context switch between two threads.
 */
        PUBLIC _port_switch
_port_switch:
        push    {r4, r5, r6, r7, r8, r9, r10, r11, lr}
#if CORTEX_USE_FPU
        vpush   {s16-s31}
#endif
        str     sp, [r1, #CONTEXT_OFFSET]
        ldr     sp, [r0, #CONTEXT_OFFSET]
#if CORTEX_USE_FPU
        vpop    {s16-s31}
#endif
        pop     {r4, r5, r6, r7, r8, r9, r10, r11, pc}

/*
 * Start a thread by invoking its work function.
 * If the work function returns @p chThdExit() is automatically invoked.
 */
        PUBLIC  _port_thread_start
_port_thread_start:
#if CH_DBG_SYSTEM_STATE_CHECK
        bl      dbg_check_unlock
#endif
#if CORTEX_SIMPLIFIED_PRIORITY
        cpsie   i
#else
        movs    r3, #CORTEX_BASEPRI_DISABLED
        msr     BASEPRI, r3
#endif
        mov     r0, r5
        blx     r4
        bl      chThdExit

/*
 * Post-IRQ switch code.
 * Exception handlers return here for context switching.
 */
        PUBLIC  _port_switch_from_isr
        PUBLIC  _port_exit_from_isr
_port_switch_from_isr:
#if CH_DBG_SYSTEM_STATE_CHECK
        bl      dbg_check_lock
#endif
        bl      chSchDoReschedule
#if CH_DBG_SYSTEM_STATE_CHECK
        bl      dbg_check_unlock
#endif
_port_exit_from_isr:
#if CORTEX_SIMPLIFIED_PRIORITY
        mov     r3, #LWRD SCB_ICSR
        movt    r3, #HWRD SCB_ICSR
        mov	r2, #ICSR_PENDSVSET
        str	r2, [r3]
        cpsie   i
.L3:    b       .L3
#else
        svc     #0
#endif

        END