/*
 * FreeRTOS Kernel V10.2.1
 * Copyright (C) 2019 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * 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.
 *
 * http://www.FreeRTOS.org
 * http://aws.amazon.com/freertos
 *
 * 1 tab == 4 spaces!
 */

/*
Changes from V3.0.0

Changes from V3.0.1
*/
#ifndef PORTMACRO_H
#define PORTMACRO_H

#if !defined(_SERIES) || _SERIES != 18
    #error "WizC supports FreeRTOS on the Microchip PIC18-series only"
#endif

#if !defined(QUICKCALL) || QUICKCALL != 1
    #error "QuickCall must be enabled (see ProjectOptions/Optimisations)"
#endif

#include <stddef.h>
#include <pic.h>

#define portCHAR        char
#define portFLOAT       float
#define portDOUBLE      portFLOAT
#define portLONG        long
#define portSHORT       short
#define portSTACK_TYPE  uint8_t
#define portBASE_TYPE   char

typedef portSTACK_TYPE StackType_t;
typedef signed char BaseType_t;
typedef unsigned char UBaseType_t;


#if( configUSE_16_BIT_TICKS == 1 )
    typedef uint16_t TickType_t;
    #define portMAX_DELAY ( TickType_t )    ( 0xFFFF )
#else
    typedef uint32_t TickType_t;
    #define portMAX_DELAY ( TickType_t )    ( 0xFFFFFFFF )
#endif

#define portBYTE_ALIGNMENT          1

/*-----------------------------------------------------------*/

/*
 * Constant used for context switch macro when we require the interrupt
 * enable state to be forced when the interrupted task is switched back in.
 */
#define portINTERRUPTS_FORCED               (0x01)

/*
 * Constant used for context switch macro when we require the interrupt
 * enable state to be unchanged when the interrupted task is switched back in.
 */
#define portINTERRUPTS_UNCHANGED            (0x00)

/* Initial interrupt enable state for newly created tasks.  This value is
 * used when a task switches in for the first time.
 */
#define portINTERRUPTS_INITIAL_STATE        (portINTERRUPTS_FORCED)

/*
 * Macros to modify the global interrupt enable bit in INTCON.
 */
#define portDISABLE_INTERRUPTS()    \
    do                              \
    {                               \
        bGIE=0;                     \
    } while(bGIE)   // MicroChip recommends this check!

#define portENABLE_INTERRUPTS()     \
    do                              \
    {                               \
        bGIE=1;                     \
    } while(0)

/*-----------------------------------------------------------*/

/*
 * Critical section macros.
 */
extern uint8_t ucCriticalNesting;

#define portNO_CRITICAL_SECTION_NESTING     ( ( uint8_t ) 0 )

#define portENTER_CRITICAL()                                        \
    do                                                              \
    {                                                               \
        portDISABLE_INTERRUPTS();                                   \
        \
        /*                                                          \
           * Now interrupts are disabled ucCriticalNesting            \
           * can be accessed directly. Increment                      \
           * ucCriticalNesting to keep a count of how                 \
           * many times portENTER_CRITICAL() has been called.         \
           */                                                         \
        ucCriticalNesting++;                                        \
    } while(0)

#define portEXIT_CRITICAL()                                         \
    do                                                              \
    {                                                               \
        if(ucCriticalNesting > portNO_CRITICAL_SECTION_NESTING)     \
        {                                                           \
            /*                                                      \
                  * Decrement the nesting count as we are leaving a      \
                  * critical section.                                    \
                  */                                                     \
            ucCriticalNesting--;                                    \
        }                                                           \
        \
        /*                                                          \
           * If the nesting level has reached zero then               \
           * interrupts should be re-enabled.                         \
           */                                                         \
        if( ucCriticalNesting == portNO_CRITICAL_SECTION_NESTING )  \
        {                                                           \
            portENABLE_INTERRUPTS();                                \
        }                                                           \
    } while(0)

/*-----------------------------------------------------------*/

/*
 * The minimal stacksize is calculated on the first reference of
 * portMINIMAL_STACK_SIZE. Some input to this calculation is
 * compiletime determined, other input is port-defined (see port.c)
 */
extern uint16_t usPortCALCULATE_MINIMAL_STACK_SIZE(void);
extern uint16_t usCalcMinStackSize;

#define portMINIMAL_STACK_SIZE                  \
    ((usCalcMinStackSize == 0)                  \
     ? usPortCALCULATE_MINIMAL_STACK_SIZE()  \
     : usCalcMinStackSize )

/*
 * WizC uses a downgrowing stack
 */
#define portSTACK_GROWTH            ( -1 )

/*-----------------------------------------------------------*/

/*
 * Macro's that pushes all the registers that make up the context of a task onto
 * the stack, then saves the new top of stack into the TCB. TOSU and TBLPTRU
 * are only saved/restored on devices with more than 64kB (32k Words) ROM.
 *
 * The stackpointer is helt by WizC in FSR2 and points to the first free byte.
 * WizC uses a "downgrowing" stack. There is no framepointer.
 *
 * We keep track of the interruptstatus using ucCriticalNesting. When this
 * value equals zero, interrupts have to be enabled upon exit from the
 * portRESTORE_CONTEXT macro.
 *
 * If this is called from an ISR then the interrupt enable bits must have been
 * set for the ISR to ever get called.  Therefore we want to save
 * ucCriticalNesting with value zero. This means the interrupts will again be
 * re-enabled when the interrupted task is switched back in.
 *
 * If this is called from a manual context switch (i.e. from a call to yield),
 * then we want to keep the current value of ucCritialNesting so it is restored
 * with its current value. This allows a yield from within a critical section.
 *
 * The compiler uses some locations at the bottom of RAM for temporary
 * storage. The compiler may also have been instructed to optimize
 * function-parameters and local variables to global storage. The compiler
 * uses an area called LocOpt for this wizC feature.
 * The total overheadstorage has to be saved in it's entirety as part of
 * a task context. These macro's store/restore from data address 0x0000 to
 * (OVERHEADPAGE0-LOCOPTSIZE+MAXLOCOPTSIZE - 1).
 * OVERHEADPAGE0, LOCOPTSIZE and MAXLOCOPTSIZE are compiler-generated
 * assembler definitions.
 */

#define portSAVE_CONTEXT( ucInterruptForced )                       \
    do                                                              \
    {                                                               \
        portDISABLE_INTERRUPTS();                                   \
        \
        _Pragma("asm")                                              \
        ;                                                       \
        ; Push the relevant SFR's onto the task's stack         \
        ;                                                       \
        movff   STATUS,POSTDEC2                                 \
        movff   WREG,POSTDEC2                                   \
        movff   BSR,POSTDEC2                                    \
        movff   PRODH,POSTDEC2                                  \
        movff   PRODL,POSTDEC2                                  \
        movff   FSR0H,POSTDEC2                                  \
        movff   FSR0L,POSTDEC2                                  \
        movff   FSR1H,POSTDEC2                                  \
        movff   FSR1L,POSTDEC2                                  \
        movff   TABLAT,POSTDEC2                                 \
        if __ROMSIZE > 0x8000                                   \
        movff   TBLPTRU,POSTDEC2                            \
        endif                                                   \
        movff   TBLPTRH,POSTDEC2                                \
        movff   TBLPTRL,POSTDEC2                                \
        if __ROMSIZE > 0x8000                                   \
            movff   PCLATU,POSTDEC2                             \
            endif                                                   \
            movff   PCLATH,POSTDEC2                                 \
            ;                                                       \
    ; Store the compiler-scratch-area as described above.   \
    ;                                                       \
    movlw   OVERHEADPAGE0-LOCOPTSIZE+MAXLOCOPTSIZE          \
    clrf    FSR0L,ACCESS                                    \
    clrf    FSR0H,ACCESS                                    \
    _rtos_S1:                                                   \
    movff   POSTINC0,POSTDEC2                               \
    decfsz  WREG,W,ACCESS                                   \
    SMARTJUMP _rtos_S1                                      \
    ;                                                       \
    ; Save the pic call/return-stack belonging to the       \
                              ; current task by copying it to the task's software-	\
			; stack. We save the hardware stack pointer (which		\
			; is the number of addresses on the stack) in the		\
			; W-register first because we need it later and it		\
			; is modified in the save-loop by executing pop's.		\
    ; After the loop the W-register is stored on the        \
    ; stack, too.                                           \
    ;                                                       \
    movf    STKPTR,W,ACCESS                                 \
    bz      _rtos_s3                                        \
    _rtos_S2:                                                   \
    if __ROMSIZE > 0x8000                                   \
        movff   TOSU,POSTDEC2                               \
        endif                                                   \
        movff   TOSH,POSTDEC2                                   \
        movff   TOSL,POSTDEC2                                   \
        pop                                                     \
        tstfsz  STKPTR,ACCESS                                   \
        SMARTJUMP _rtos_S2                                      \
    _rtos_s3:                                                   \
        movwf   POSTDEC2,ACCESS                                 \
        ;                                                       \
    ; Next the value for ucCriticalNesting used by the      \
        ; task is stored on the stack. When                     \
    ; (ucInterruptForced == portINTERRUPTS_FORCED), we save \
        ; it as 0 (portNO_CRITICAL_SECTION_NESTING).            \
        ;                                                       \
        if ucInterruptForced == portINTERRUPTS_FORCED           \
        clrf POSTDEC2,ACCESS                                \
        else                                                    \
            movff   ucCriticalNesting,POSTDEC2                  \
            endif                                                   \
            ;                                                       \
    ; Save the new top of the software stack in the TCB.    \
    ;                                                       \
    movff   pxCurrentTCB,FSR0L                              \
    movff   pxCurrentTCB+1,FSR0H                            \
    movff   FSR2L,POSTINC0                                  \
    movff   FSR2H,POSTINC0                                  \
    _Pragma("asmend")                                           \
    } while(0)

/************************************************************/

/*
 * This is the reverse of portSAVE_CONTEXT.
 */
#define portRESTORE_CONTEXT()                                       \
    do                                                              \
    {                                                               \
        _Pragma("asm")                                              \
        ;                                                       \
        ; Set FSR0 to point to pxCurrentTCB->pxTopOfStack.      \
        ;                                                       \
        movff   pxCurrentTCB,FSR0L                              \
        movff   pxCurrentTCB+1,FSR0H                            \
        ;                                                       \
        ; De-reference FSR0 to set the address it holds into    \
        ; FSR2 (i.e. *( pxCurrentTCB->pxTopOfStack ) ). FSR2    \
        ; is used by wizC as stackpointer.                      \
        ;                                                       \
        movff   POSTINC0,FSR2L                                  \
        movff   POSTINC0,FSR2H                                  \
        ;                                                       \
        ; Next, the value for ucCriticalNesting used by the     \
        ; task is retrieved from the stack.                     \
    ;                                                       \
    movff   PREINC2,ucCriticalNesting                       \
    ;                                                       \
    ; Rebuild the pic call/return-stack. The number of      \
                                 ; return addresses is the next item on the task stack.  \
                                          ; Save this number in PRODL. Then fetch the addresses   \
    ; and store them on the hardwarestack.                  \
    ; The datasheets say we can't use movff here...			\
			;														\
			movff	PREINC2,PRODL	// Use PRODL as tempregister	\
			clrf	STKPTR,ACCESS									\
		_rtos_R1:													\
			push													\
			movf	PREINC2,W,ACCESS								\
			movwf	TOSL,ACCESS										\
			movf	PREINC2,W,ACCESS								\
			movwf	TOSH,ACCESS										\
			if __ROMSIZE > 0x8000									\
				movf	PREINC2,W,ACCESS							\
				movwf	TOSU,ACCESS									\
			else													\
				clrf	TOSU,ACCESS									\
			endif													\
			decfsz	PRODL,F,ACCESS									\
			SMARTJUMP _rtos_R1										\
			;														\
			; Restore the compiler's working storage area to page 0	\
    ;                                                       \
    movlw   OVERHEADPAGE0-LOCOPTSIZE+MAXLOCOPTSIZE          \
    movwf   FSR0L,ACCESS                                    \
    clrf    FSR0H,ACCESS                                    \
    _rtos_R2:                                                   \
    decf    FSR0L,F,ACCESS                                  \
    movff   PREINC2,INDF0                                   \
    tstfsz  FSR0L,ACCESS                                    \
    SMARTJUMP _rtos_R2                                      \
    ;                                                       \
    ; Restore the sfr's forming the tasks context.			\
			; We cannot yet restore bsr, w and status because		\
			; we need these	registers for a final test.				\
			;														\
			movff	PREINC2,PCLATH									\
			if __ROMSIZE > 0x8000									\
				movff	PREINC2,PCLATU								\
			else													\
				clrf	PCLATU,ACCESS								\
			endif													\
			movff	PREINC2,TBLPTRL									\
			movff	PREINC2,TBLPTRH									\
			if __ROMSIZE > 0x8000									\
				movff	PREINC2,TBLPTRU								\
			else													\
				clrf	TBLPTRU,ACCESS								\
			endif													\
			movff	PREINC2,TABLAT									\
			movff	PREINC2,FSR1L									\
			movff	PREINC2,FSR1H									\
			movff	PREINC2,FSR0L									\
			movff	PREINC2,FSR0H									\
			movff	PREINC2,PRODL									\
			movff	PREINC2,PRODH									\
			;														\
			; The return from portRESTORE_CONTEXT() depends on		\
			; the value of ucCriticalNesting. When it is zero,		\
			; interrupts need to be enabled. This is done via a		\
			; retfie instruction because we need the				\
			; interrupt-enabling and the return to the restored		\
			; task to be uninterruptable.							\
	 		; Because bsr, status and W are affected by the test	\
	 		; they are restored after the test.						\
			;														\
			movlb	ucCriticalNesting>>8							\
			tstfsz	ucCriticalNesting,BANKED						\
			SMARTJUMP _rtos_R4										\
		_rtos_R3:													\
			movff	PREINC2,BSR										\
			movff	PREINC2,WREG									\
			movff	PREINC2,STATUS									\
			retfie	0		; Return enabling interrupts			\
		_rtos_R4:													\
			movff	PREINC2,BSR										\
			movff	PREINC2,WREG									\
			movff	PREINC2,STATUS									\
			return	0		; Return without affecting interrupts	\
		_Pragma("asmend")											\
} while(0)

/*-----------------------------------------------------------*/

#define portTICK_PERIOD_MS  ( ( TickType_t ) 1000 / configTICK_RATE_HZ )

/*-----------------------------------------------------------*/

extern void vPortYield(void);
#define portYIELD()             vPortYield()

#define portNOP()   _Pragma("asm")                                  \
    nop                                         \
    _Pragma("asmend")

/*-----------------------------------------------------------*/

#define portTASK_FUNCTION( xFunction, pvParameters )        \
    void pointed xFunction( void *pvParameters )        \
    _Pragma(asmfunc xFunction)

#define portTASK_FUNCTION_PROTO     portTASK_FUNCTION
/*-----------------------------------------------------------*/


#define volatile
#define register

#endif /* PORTMACRO_H */

