From: rtel <rtel@1d2547de-c912-0410-9cb9-b8ca96c0e9e2>
Date: Thu, 27 Sep 2018 17:25:17 +0000 (+0000)
Subject: RISC-V tasks now context switching to each other using taskYIELD() - not fully tested... 
X-Git-Tag: V10.2.0~57
X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=c3ad5844ac02866e0ca3710c6ac4531af973c006;p=freertos

RISC-V tasks now context switching to each other using taskYIELD() - not fully tested yet.

git-svn-id: https://svn.code.sf.net/p/freertos/code/trunk@2585 1d2547de-c912-0410-9cb9-b8ca96c0e9e2
---

diff --git a/FreeRTOS/Source/portable/GCC/RISC-V-RV32/port.c b/FreeRTOS/Source/portable/GCC/RISC-V-RV32/port.c
index 5e66d08c4..24611a9be 100644
--- a/FreeRTOS/Source/portable/GCC/RISC-V-RV32/port.c
+++ b/FreeRTOS/Source/portable/GCC/RISC-V-RV32/port.c
@@ -50,14 +50,14 @@ static void prvTaskExitError( void );
 
 /* Used to program the machine timer compare register. */
 static uint64_t ullNextTime = 0ULL;
-static volatile uint64_t * const pullMachineTimerCompareRegister = ( volatile uint64_t * const ) 0x2004000;
+static volatile uint64_t * const pullMachineTimerCompareRegister = ( volatile uint64_t * const ) ( configCTRL_BASE + 0x4000 );
 
 /*-----------------------------------------------------------*/
 
 void prvTaskExitError( void )
 {
 volatile uint32_t ulx = 0;
-#warning prvTaskExitError not used yet.
+
 	/* A function that implements a task must not exit or attempt to return to
 	its caller as there is nothing to return to.  If a task wants to exit it
 	should instead call vTaskDelete( NULL ).
@@ -154,6 +154,8 @@ StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t px
 //	pxTopOfStack--;
 //	*pxTopOfStack = ( StackType_t ) 2;  /* Stack pointer. */
 //	pxTopOfStack--;
+	*pxTopOfStack = ( StackType_t ) prvTaskExitError;
+	pxTopOfStack--;
 	*pxTopOfStack = ( StackType_t ) pxCode;
 
 	return pxTopOfStack;
@@ -163,8 +165,8 @@ StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t px
 void vPortSetupTimerInterrupt( void )
 {
 uint32_t ulCurrentTimeHigh, ulCurrentTimeLow;
-volatile uint32_t * const pulTimeHigh = ( volatile uint32_t * const ) 0x200BFF8;
-volatile uint32_t * const pulTimeLow = ( volatile uint32_t * const ) 0x200BFFc;
+volatile uint32_t * const pulTimeHigh = ( volatile uint32_t * const ) ( configCTRL_BASE + 0xBFF8 );
+volatile uint32_t * const pulTimeLow = ( volatile uint32_t * const ) ( configCTRL_BASE + 0xBFFc );
 
 	do
 	{
@@ -185,9 +187,13 @@ volatile uint32_t * const pulTimeLow = ( volatile uint32_t * const ) 0x200BFFc;
 
 void Software_IRQHandler( void )
 {
-	vTaskSwitchContext();
-}
+volatile uint32_t * const ulSoftInterrupt = ( uint32_t * ) configCTRL_BASE;
 
+	vTaskSwitchContext();
 
+	/* Clear software interrupt. */
+	*ulSoftInterrupt = 0UL;
+}
+/*-----------------------------------------------------------*/
 
 
diff --git a/FreeRTOS/Source/portable/GCC/RISC-V-RV32/portASM.S b/FreeRTOS/Source/portable/GCC/RISC-V-RV32/portASM.S
index d86757e8c..5efe94f07 100644
--- a/FreeRTOS/Source/portable/GCC/RISC-V-RV32/portASM.S
+++ b/FreeRTOS/Source/portable/GCC/RISC-V-RV32/portASM.S
@@ -47,80 +47,83 @@
 
 .align 8
 xPortStartScheduler:
-	lw	sp, pxCurrentTCB 			/* Load pxCurrentTCB. */
-	lw	sp, 0( sp )	 				/* Read sp from first TCB member. */
-	lw	x1, 0( sp )
-	lw	x5, 1 * WORD_SIZE( sp ) 	/* t0 */
-	lw	x6, 2 * WORD_SIZE( sp ) 	/* t1 */
-	lw	x7, 3 * WORD_SIZE( sp ) 	/* t2 */
-	lw	x8, 4 * WORD_SIZE( sp ) 	/* s0/fp */
-	lw	x9, 5 * WORD_SIZE( sp ) 	/* s1 */
-	lw	x10, 6 * WORD_SIZE( sp ) 	/* a0 */
-	lw	x11, 7 * WORD_SIZE( sp ) 	/* a1 */
-	lw	x12, 8 * WORD_SIZE( sp ) 	/* a2 */
-	lw	x13, 9 * WORD_SIZE( sp ) 	/* a3 */
-	lw	x14, 10 * WORD_SIZE( sp ) 	/* a4 */
-	lw	x15, 11 * WORD_SIZE( sp ) 	/* a5 */
-	lw	x16, 12 * WORD_SIZE( sp ) 	/* a6 */
-	lw	x17, 13 * WORD_SIZE( sp ) 	/* a7 */
-	lw	x18, 14 * WORD_SIZE( sp ) 	/* s2 */
-	lw	x19, 15 * WORD_SIZE( sp ) 	/* s3 */
-	lw	x20, 16 * WORD_SIZE( sp ) 	/* s4 */
-	lw	x21, 17 * WORD_SIZE( sp ) 	/* s5 */
-	lw	x22, 18 * WORD_SIZE( sp ) 	/* s6 */
-	lw	x23, 19 * WORD_SIZE( sp ) 	/* s7 */
-	lw	x24, 20 * WORD_SIZE( sp ) 	/* s8 */
-	lw	x25, 21 * WORD_SIZE( sp ) 	/* s9 */
-	lw	x26, 22 * WORD_SIZE( sp ) 	/* s10 */
-	lw	x27, 23 * WORD_SIZE( sp ) 	/* s11 */
-	lw	x28, 24 * WORD_SIZE( sp ) 	/* t3 */
-	lw	x29, 25 * WORD_SIZE( sp ) 	/* t4 */
-	lw	x30, 26 * WORD_SIZE( sp ) 	/* t5 */
-	lw	x31, 27 * WORD_SIZE( sp ) 	/* t6 */
-	addi 	sp, sp, CONTEXT_SIZE
-	csrs	mie, 8					/* Enable soft interrupt. */
-	csrs 	mstatus, 8				/* Enable interrupts. */
-	ret
+    lw  sp, pxCurrentTCB            /* Load pxCurrentTCB. */
+    lw  sp, 0( sp )                 /* Read sp from first TCB member. */
+
+    lw  x1, 0( sp ) /* Note for starting the scheduler the exception return address is used as the function return address. */
+    lw  x5, 2 * WORD_SIZE( sp )     /* t0 */
+    lw  x6, 3 * WORD_SIZE( sp )     /* t1 */
+    lw  x7, 4 * WORD_SIZE( sp )     /* t2 */
+    lw  x8, 5 * WORD_SIZE( sp )     /* s0/fp */
+    lw  x9, 6 * WORD_SIZE( sp )     /* s1 */
+    lw  x10, 7 * WORD_SIZE( sp )    /* a0 */
+    lw  x11, 8 * WORD_SIZE( sp )    /* a1 */
+    lw  x12, 9 * WORD_SIZE( sp )    /* a2 */
+    lw  x13, 10 * WORD_SIZE( sp )   /* a3 */
+    lw  x14, 11 * WORD_SIZE( sp )   /* a4 */
+    lw  x15, 12 * WORD_SIZE( sp )   /* a5 */
+    lw  x16, 13 * WORD_SIZE( sp )   /* a6 */
+    lw  x17, 14 * WORD_SIZE( sp )   /* a7 */
+    lw  x18, 15 * WORD_SIZE( sp )   /* s2 */
+    lw  x19, 16 * WORD_SIZE( sp )   /* s3 */
+    lw  x20, 17 * WORD_SIZE( sp )   /* s4 */
+    lw  x21, 18 * WORD_SIZE( sp )   /* s5 */
+    lw  x22, 19 * WORD_SIZE( sp )   /* s6 */
+    lw  x23, 20 * WORD_SIZE( sp )   /* s7 */
+    lw  x24, 21 * WORD_SIZE( sp )   /* s8 */
+    lw  x25, 22 * WORD_SIZE( sp )   /* s9 */
+    lw  x26, 23 * WORD_SIZE( sp )   /* s10 */
+    lw  x27, 24 * WORD_SIZE( sp )   /* s11 */
+    lw  x28, 25 * WORD_SIZE( sp )   /* t3 */
+    lw  x29, 26 * WORD_SIZE( sp )   /* t4 */
+    lw  x30, 27 * WORD_SIZE( sp )   /* t5 */
+    lw  x31, 28 * WORD_SIZE( sp )   /* t6 */
+    addi    sp, sp, CONTEXT_SIZE
+    csrs    mstatus, 8              /* Enable machine interrupts. */
+    csrs    mie, 8                  /* Enable soft interrupt. */
+    ret
 
 /*-----------------------------------------------------------*/
 
 .align 8
 vPortTrapHandler:
 	addi sp, sp, -CONTEXT_SIZE
-	sw x1, 0( sp )
-	sw x5, 1 * WORD_SIZE( sp )
-	sw x6, 2 * WORD_SIZE( sp )
-	sw x7, 3 * WORD_SIZE( sp )
-	sw x8, 4 * WORD_SIZE( sp )
-	sw x9, 5 * WORD_SIZE( sp )
-	sw x10, 6 * WORD_SIZE( sp )
-	sw x11, 7 * WORD_SIZE( sp )
-	sw x12, 8 * WORD_SIZE( sp )
-	sw x13, 9 * WORD_SIZE( sp )
-	sw x14, 10 * WORD_SIZE( sp )
-	sw x15, 11 * WORD_SIZE( sp )
-	sw x16, 12 * WORD_SIZE( sp )
-	sw x17, 13 * WORD_SIZE( sp )
-	sw x18, 14 * WORD_SIZE( sp )
-	sw x19, 15 * WORD_SIZE( sp )
-	sw x20, 16 * WORD_SIZE( sp )
-	sw x21, 17 * WORD_SIZE( sp )
-	sw x22, 18 * WORD_SIZE( sp )
-	sw x23, 19 * WORD_SIZE( sp )
-	sw x24, 20 * WORD_SIZE( sp )
-	sw x25, 21 * WORD_SIZE( sp )
-	sw x26, 22 * WORD_SIZE( sp )
-	sw x27, 23 * WORD_SIZE( sp )
-	sw x28, 24 * WORD_SIZE( sp )
-	sw x29, 25 * WORD_SIZE( sp )
-	sw x30, 26 * WORD_SIZE( sp )
-	sw x31, 27 * WORD_SIZE( sp )
+	sw x1, 1( sp )
+	sw x5, 2 * WORD_SIZE( sp )
+	sw x6, 3 * WORD_SIZE( sp )
+	sw x7, 4 * WORD_SIZE( sp )
+	sw x8, 5 * WORD_SIZE( sp )
+	sw x9, 6 * WORD_SIZE( sp )
+	sw x10, 7 * WORD_SIZE( sp )
+	sw x11, 8 * WORD_SIZE( sp )
+	sw x12, 9 * WORD_SIZE( sp )
+	sw x13, 10 * WORD_SIZE( sp )
+	sw x14, 11 * WORD_SIZE( sp )
+	sw x15, 12 * WORD_SIZE( sp )
+	sw x16, 13 * WORD_SIZE( sp )
+	sw x17, 14 * WORD_SIZE( sp )
+	sw x18, 15 * WORD_SIZE( sp )
+	sw x19, 16 * WORD_SIZE( sp )
+	sw x20, 17 * WORD_SIZE( sp )
+	sw x21, 18 * WORD_SIZE( sp )
+	sw x22, 19 * WORD_SIZE( sp )
+	sw x23, 20 * WORD_SIZE( sp )
+	sw x24, 21 * WORD_SIZE( sp )
+	sw x25, 22 * WORD_SIZE( sp )
+	sw x26, 23 * WORD_SIZE( sp )
+	sw x27, 24 * WORD_SIZE( sp )
+	sw x28, 25 * WORD_SIZE( sp )
+	sw x29, 26 * WORD_SIZE( sp )
+	sw x30, 27 * WORD_SIZE( sp )
+	sw x31, 28 * WORD_SIZE( sp )
+
+    /* Save exception return address. */
+    csrr t0, mepc
+    sw t0, 0( sp )
+
     lw  t0, pxCurrentTCB            /* Load pxCurrentTCB. */
     sw  sp, 0( t0 )                 /* Write sp from first TCB member. */
 
-	csrr t0, mepc
-	sw t0, 31 * WORD_SIZE( sp )
-
 	csrr a0, mcause
 	csrr a1, mepc
 	mv a2, sp
@@ -131,37 +134,43 @@ vPortTrapHandler:
 	li t0, 0x00001800 /* MSTATUS MPP */
 	csrs mstatus, t0
 
-	/* Cut and past restore code from xPortStartScheduler - can be made a macro
-	but that makes debugging harder. */
-	lw	sp, pxCurrentTCB 			/* Load pxCurrentTCB. */
-	lw	sp, 0( sp )	 				/* Read sp from first TCB member. */
-	lw	x1, 0( sp )
-	lw	x5, 1 * WORD_SIZE( sp ) 	/* t0 */
-	lw	x6, 2 * WORD_SIZE( sp ) 	/* t1 */
-	lw	x7, 3 * WORD_SIZE( sp ) 	/* t2 */
-	lw	x8, 4 * WORD_SIZE( sp ) 	/* s0/fp */
-	lw	x9, 5 * WORD_SIZE( sp ) 	/* s1 */
-	lw	x10, 6 * WORD_SIZE( sp ) 	/* a0 */
-	lw	x11, 7 * WORD_SIZE( sp ) 	/* a1 */
-	lw	x12, 8 * WORD_SIZE( sp ) 	/* a2 */
-	lw	x13, 9 * WORD_SIZE( sp ) 	/* a3 */
-	lw	x14, 10 * WORD_SIZE( sp ) 	/* a4 */
-	lw	x15, 11 * WORD_SIZE( sp ) 	/* a5 */
-	lw	x16, 12 * WORD_SIZE( sp ) 	/* a6 */
-	lw	x17, 13 * WORD_SIZE( sp ) 	/* a7 */
-	lw	x18, 14 * WORD_SIZE( sp ) 	/* s2 */
-	lw	x19, 15 * WORD_SIZE( sp ) 	/* s3 */
-	lw	x20, 16 * WORD_SIZE( sp ) 	/* s4 */
-	lw	x21, 17 * WORD_SIZE( sp ) 	/* s5 */
-	lw	x22, 18 * WORD_SIZE( sp ) 	/* s6 */
-	lw	x23, 19 * WORD_SIZE( sp ) 	/* s7 */
-	lw	x24, 20 * WORD_SIZE( sp ) 	/* s8 */
-	lw	x25, 21 * WORD_SIZE( sp ) 	/* s9 */
-	lw	x26, 22 * WORD_SIZE( sp ) 	/* s10 */
-	lw	x27, 23 * WORD_SIZE( sp ) 	/* s11 */
-	lw	x28, 24 * WORD_SIZE( sp ) 	/* t3 */
-	lw	x29, 25 * WORD_SIZE( sp ) 	/* t4 */
-	lw	x30, 26 * WORD_SIZE( sp ) 	/* t5 */
-	lw	x31, 27 * WORD_SIZE( sp ) 	/* t6 */
-	addi sp, sp, CONTEXT_SIZE
-	mret
+    lw  sp, pxCurrentTCB            /* Load pxCurrentTCB. */
+    lw  sp, 0( sp )                 /* Read sp from first TCB member. */
+
+    /* Load mret with the address of the first task. */
+    lw t0, 0( sp )
+    csrw mepc, t0
+
+    lw  x1, 1( sp )
+    lw  x5, 2 * WORD_SIZE( sp )     /* t0 */
+    lw  x6, 3 * WORD_SIZE( sp )     /* t1 */
+    lw  x7, 4 * WORD_SIZE( sp )     /* t2 */
+    lw  x8, 5 * WORD_SIZE( sp )     /* s0/fp */
+    lw  x9, 6 * WORD_SIZE( sp )     /* s1 */
+    lw  x10, 7 * WORD_SIZE( sp )    /* a0 */
+    lw  x11, 8 * WORD_SIZE( sp )    /* a1 */
+    lw  x12, 9 * WORD_SIZE( sp )    /* a2 */
+    lw  x13, 10 * WORD_SIZE( sp )   /* a3 */
+    lw  x14, 11 * WORD_SIZE( sp )   /* a4 */
+    lw  x15, 12 * WORD_SIZE( sp )   /* a5 */
+    lw  x16, 13 * WORD_SIZE( sp )   /* a6 */
+    lw  x17, 14 * WORD_SIZE( sp )   /* a7 */
+    lw  x18, 15 * WORD_SIZE( sp )   /* s2 */
+    lw  x19, 16 * WORD_SIZE( sp )   /* s3 */
+    lw  x20, 17 * WORD_SIZE( sp )   /* s4 */
+    lw  x21, 18 * WORD_SIZE( sp )   /* s5 */
+    lw  x22, 19 * WORD_SIZE( sp )   /* s6 */
+    lw  x23, 20 * WORD_SIZE( sp )   /* s7 */
+    lw  x24, 21 * WORD_SIZE( sp )   /* s8 */
+    lw  x25, 22 * WORD_SIZE( sp )   /* s9 */
+    lw  x26, 23 * WORD_SIZE( sp )   /* s10 */
+    lw  x27, 24 * WORD_SIZE( sp )   /* s11 */
+    lw  x28, 25 * WORD_SIZE( sp )   /* t3 */
+    lw  x29, 26 * WORD_SIZE( sp )   /* t4 */
+    lw  x30, 27 * WORD_SIZE( sp )   /* t5 */
+    lw  x31, 28 * WORD_SIZE( sp )   /* t6 */
+    addi    sp, sp, CONTEXT_SIZE
+
+    mret
+
+
diff --git a/FreeRTOS/Source/portable/GCC/RISC-V-RV32/portmacro.h b/FreeRTOS/Source/portable/GCC/RISC-V-RV32/portmacro.h
index 7132bf4ba..a256d5b0c 100644
--- a/FreeRTOS/Source/portable/GCC/RISC-V-RV32/portmacro.h
+++ b/FreeRTOS/Source/portable/GCC/RISC-V-RV32/portmacro.h
@@ -70,7 +70,7 @@ not need to be guarded with a critical section. */
 
 
 /* Scheduler utilities. */
-#define portYIELD() {  volatile uint32_t * const ulSoftInterrupt = ( uint32_t * ) 0x2000000;	*ulSoftInterrupt = 1UL; }
+#define portYIELD() {  volatile uint32_t * const ulSoftInterrupt = ( uint32_t * ) configCTRL_BASE;	*ulSoftInterrupt = 1UL; }
 #define portEND_SWITCHING_ISR( xSwitchRequired ) if( xSwitchRequired ) vPortYield()
 #define portYIELD_FROM_ISR( x ) portEND_SWITCHING_ISR( x )
 /*-----------------------------------------------------------*/