diff --git a/portable/GCC/RISC-V/port.c b/portable/GCC/RISC-V/port.c
index a0acdf4c8..ac3f6dbe2 100644
--- a/portable/GCC/RISC-V/port.c
+++ b/portable/GCC/RISC-V/port.c
@@ -25,11 +25,9 @@
  * 1 tab == 4 spaces!
  */
 
-/* ------------------------------------------------------------------
- * This file is part of the FreeRTOS distribution and was contributed
- * to the project by SiFive
- * ------------------------------------------------------------------
- */
+/*-----------------------------------------------------------
+ * Implementation of functions defined in portable.h for the RISC-V RV32 port.
+ *----------------------------------------------------------*/
 
 /* Scheduler includes. */
 #include "FreeRTOS.h"
@@ -120,69 +118,31 @@ task stack, not the ISR stack). */
 
 #if( configMTIME_BASE_ADDRESS != 0 ) && ( configMTIMECMP_BASE_ADDRESS != 0 )
 
-    #if( __riscv_xlen == 32 )
-        void vPortSetupTimerInterrupt( void )
-        {
-            uint32_t ulCurrentTimeHigh, ulCurrentTimeLow;
-            volatile uint32_t * const pulTimeHigh = ( volatile uint32_t * const ) ( ( configMTIME_BASE_ADDRESS ) + 4UL ); /* 8-byte typer so high 32-bit word is 4 bytes up. */
-            volatile uint32_t * const pulTimeLow = ( volatile uint32_t * const ) ( configMTIME_BASE_ADDRESS );
-            volatile uint32_t * pulTimeCompareRegisterHigh;
-            volatile uint32_t * pulTimeCompareRegisterLow;
+	void vPortSetupTimerInterrupt( void )
+	{
+	uint32_t ulCurrentTimeHigh, ulCurrentTimeLow;
+	volatile uint32_t * const pulTimeHigh = ( volatile uint32_t * const ) ( ( configMTIME_BASE_ADDRESS ) + 4UL ); /* 8-byte typer so high 32-bit word is 4 bytes up. */
+	volatile uint32_t * const pulTimeLow = ( volatile uint32_t * const ) ( configMTIME_BASE_ADDRESS );
+	volatile uint32_t ulHartId;
 
-            volatile uint32_t ulHartId;
+		__asm volatile( "csrr %0, mhartid" : "=r"( ulHartId ) );
+		pullMachineTimerCompareRegister  = ( volatile uint64_t * ) ( ullMachineTimerCompareRegisterBase + ( ulHartId * sizeof( uint64_t ) ) );
 
-            __asm volatile ( "csrr %0, mhartid" : "=r" ( ulHartId ) );
+		do
+		{
+			ulCurrentTimeHigh = *pulTimeHigh;
+			ulCurrentTimeLow = *pulTimeLow;
+		} while( ulCurrentTimeHigh != *pulTimeHigh );
 
-			/* pullMachineTimerCompareRegister is used by freertos_risc_v_trap_handler */
-            pullMachineTimerCompareRegister = ( volatile uint64_t * ) ( ullMachineTimerCompareRegisterBase + ( ulHartId * sizeof( uint64_t ) ) );
-            pulTimeCompareRegisterLow = ( volatile uint32_t * ) ( ullMachineTimerCompareRegisterBase + ( ulHartId * sizeof( uint64_t ) ) );
-            pulTimeCompareRegisterHigh = ( volatile uint32_t * ) ( ullMachineTimerCompareRegisterBase + ( ulHartId * sizeof( uint64_t ) ) + 4UL );
+		ullNextTime = ( uint64_t ) ulCurrentTimeHigh;
+		ullNextTime <<= 32ULL; /* High 4-byte word is 32-bits up. */
+		ullNextTime |= ( uint64_t ) ulCurrentTimeLow;
+		ullNextTime += ( uint64_t ) uxTimerIncrementsForOneTick;
+		*pullMachineTimerCompareRegister = ullNextTime;
 
-            do
-            {
-                ulCurrentTimeHigh = *pulTimeHigh;
-                ulCurrentTimeLow = *pulTimeLow;
-            } while( ulCurrentTimeHigh != *pulTimeHigh );
-
-            ullNextTime = ( uint64_t ) ulCurrentTimeHigh;
-            ullNextTime <<= 32ULL; /* High 4-byte word is 32-bits up. */
-            ullNextTime |= (( uint64_t ) ulCurrentTimeLow );
-            ullNextTime += (( uint64_t ) uxTimerIncrementsForOneTick );
-            /* Per spec, the RISC-V MTIME/MTIMECMP registers are 64 bit,
-             * and are NOT internally latched for multiword transfers.
-             * Need to be careful about sequencing to avoid triggering
-             * spurious interrupts: For that set the high word to a max
-             * value first.
-             */
-            *pulTimeCompareRegisterHigh = 0xFFFFFFFF;
-            *pulTimeCompareRegisterLow = (uint32_t)( ullNextTime );
-            *pulTimeCompareRegisterHigh = (uint32_t)( ullNextTime >> 32ULL );
-
-            /* Prepare the time to use after the next tick interrupt. */
-            ullNextTime += ( uint64_t ) uxTimerIncrementsForOneTick;
-        }
-    #endif /* __riscv_xlen == 32 */
-
-    #if( __riscv_xlen == 64 )
-        void vPortSetupTimerInterrupt( void )
-        {
-            volatile uint32_t * const pulTime = ( volatile uint32_t * const ) ( configMTIME_BASE_ADDRESS );
-
-            volatile uint32_t ulHartId;
-
-            __asm volatile ( "csrr %0, mhartid" : "=r" ( ulHartId ) );
-
-            pullMachineTimerCompareRegister = ( volatile uint64_t * ) ( ullMachineTimerCompareRegisterBase + ( ulHartId * sizeof( uint64_t ) ) );
-
-            ullNextTime = *pulTime;
-
-            ullNextTime += ( uint64_t ) uxTimerIncrementsForOneTick;
-            *pullMachineTimerCompareRegister = ullNextTime;
-
-            /* Prepare the time to use after the next tick interrupt. */
-            ullNextTime += ( uint64_t ) uxTimerIncrementsForOneTick;
-        }
-    #endif /* __riscv_xlen == 64 */
+		/* Prepare the time to use after the next tick interrupt. */
+		ullNextTime += ( uint64_t ) uxTimerIncrementsForOneTick;
+	}
 
 #endif /* ( configMTIME_BASE_ADDRESS != 0 ) && ( configMTIME_BASE_ADDRESS != 0 ) */
 /*-----------------------------------------------------------*/
@@ -218,7 +178,20 @@ extern void xPortStartFirstTask( void );
 	configure whichever clock is to be used to generate the tick interrupt. */
 	vPortSetupTimerInterrupt();
 
-    /* Enabling mtime and external interrupts will be made into xPortStartFirstTask function */
+	#if( ( configMTIME_BASE_ADDRESS != 0 ) && ( configMTIMECMP_BASE_ADDRESS != 0 ) )
+	{
+		/* Enable mtime and external interrupts.  1<<7 for timer interrupt, 1<<11
+		for external interrupt.  _RB_ What happens here when mtime is not present as
+		with pulpino? */
+		__asm volatile( "csrs mie, %0" :: "r"(0x880) );
+	}
+	#else
+	{
+		/* Enable external interrupts. */
+		__asm volatile( "csrs mie, %0" :: "r"(0x800) );
+	}
+	#endif /* ( configMTIME_BASE_ADDRESS != 0 ) && ( configMTIMECMP_BASE_ADDRESS != 0 ) */
+
 	xPortStartFirstTask();
 
 	/* Should not get here as after calling xPortStartFirstTask() only tasks
@@ -232,26 +205,8 @@ void vPortEndScheduler( void )
 	/* Not implemented. */
 	for( ;; );
 }
-/*-----------------------------------------------------------*/
 
-#if( configENABLE_FPU == 1 )
-	void vPortSetupFPU( void )
-	{
-		#ifdef __riscv_fdiv
-		__asm__ __volatile__ (
-			"csrr t0, misa \n"			/* Get misa */
-			"li   t1, 0x10028 \n"		/* 0x10028 = Q,F,D Quad, Single or Double precission floating point */
-			"and  t0, t0, t1 \n"
-			"beqz t0, 1f \n"			/* check if Q,F or D is present into misa */
-			"csrr t0, mstatus \n"		/* Floating point unit is present so need to put it into initial state */
-			"lui  t1, 0x2 \n"			/* t1 =  0x1 << 12 */
-			"or   t0, t0, t1 \n"
-			"csrw mstatus, t0 \n"		/* Set FS to initial state */
-			"csrwi fcsr, 0 \n"			/* Clear Floating-point Control and Status Register */
-			"1: \n"
-			:::
-		);
-		#endif /* __riscv_fdiv */
-	}
-#endif /* configENABLE_FPU */
-/*-----------------------------------------------------------*/
+
+
+
+
diff --git a/portable/GCC/RISC-V/portASM.S b/portable/GCC/RISC-V/portASM.S
index 4a6192130..7f9c48476 100644
--- a/portable/GCC/RISC-V/portASM.S
+++ b/portable/GCC/RISC-V/portASM.S
@@ -55,56 +55,17 @@
  * registers.
  *
  */
-
-/* ------------------------------------------------------------------
- * This file is part of the FreeRTOS distribution and was contributed
- * to the project by SiFive
- * ------------------------------------------------------------------
- */
-
-#if( __riscv_xlen == 64 )
+#if __riscv_xlen == 64
+	#define portWORD_SIZE 8
 	#define store_x sd
 	#define load_x ld
-#elif( __riscv_xlen == 32 )
+#elif __riscv_xlen == 32
 	#define store_x sw
 	#define load_x lw
+	#define portWORD_SIZE 4
 #else
 	#error Assembler did not define __riscv_xlen
-#endif /* ( __riscv_xlen == xx ) */
-
-/* Nb registers to save */
-#ifdef __riscv_32e
-#define portasmNB_REGS_SAVED			(16)
-#else
-#define portasmNB_REGS_SAVED			(32)
-#endif /* __riscv_32e */
-
-#define portWORD_SIZE					(__riscv_xlen / 8)
-
-/* Number of FPU register */
-#ifdef __riscv_fdiv
-	#define MSTATUS_FS           0x00006000 /* Floating-point Status */
-	#define MSTATUS_FS_OFF       0x00000000
-	#define MSTATUS_FS_INITIAL   0x00002000
-	#define MSTATUS_FS_CLEAN     0x00004000
-	#define MSTATUS_FS_DIRTY     0x00006000
-
-	#if __riscv_flen == 32
-		#define store_fpu fsw
-		#define load_fpu flw
-	#endif /* __riscv_flen == 32 */
-
-	#if __riscv_flen == 64
-		#define store_fpu fsd
-		#define load_fpu fld
-	#endif /* __riscv_flen == 64 */
-
-	#define portasmFPU_CONTEXT_SIZE			(32)
-	#define portFPUWORD_SIZE 				(__riscv_flen / 8)
-#else
-	#define portasmFPU_CONTEXT_SIZE			(0)
-	#define portFPUWORD_SIZE				(0)
-#endif /* __riscv_fdiv */
+#endif
 
 #include "freertos_risc_v_chip_specific_extensions.h"
 
@@ -124,47 +85,20 @@ definitions. */
 	#error freertos_risc_v_chip_specific_extensions.h must define portasmHAS_MTIME to either 1 (MTIME clock present) or 0 (MTIME clock not present).  See https://www.FreeRTOS.org/Using-FreeRTOS-on-RISC-V.html
 #endif
 
-#ifndef portHANDLE_INTERRUPT
-	#error portHANDLE_INTERRUPT must be defined to the function to be called to handle external/peripheral interrupts.
+#ifndef portasmHANDLE_INTERRUPT
+	#error portasmHANDLE_INTERRUPT must be defined to the function to be called to handle external/peripheral interrupts.  portasmHANDLE_INTERRUPT can be defined on the assembler command line or in the appropriate freertos_risc_v_chip_specific_extensions.h header file.  https://www.FreeRTOS.org/Using-FreeRTOS-on-RISC-V.html
 #endif
 
-#ifndef portHANDLE_EXCEPTION
-	#error portHANDLE_EXCEPTION must be defined to the function to be called to handle execptions.
- #endif
-
 #ifndef portasmHAS_SIFIVE_CLINT
 	#define portasmHAS_SIFIVE_CLINT 0
 #endif
 
-/*
- * To maintain RISCV ABI stack alignment requirements (16bytes)
- * this data structure must be a MULTIPLE of 16 bytes in size.
- * 32 Registers (for standard core) is 16byte aligned :)
- * We add space to save additional information so it must be multiple of 4.
- * mepc 33th register 
- * mstatus 34th register
- * ruf 35th register
- * ruf 36th register
- */
-
-#define PORT_CONTEXT_mepcIDX		(portasmNB_REGS_SAVED)
-#define PORT_CONTEXT_mstatusIDX		(portasmNB_REGS_SAVED + 1)
-
-#define portasmLAST_BASE_REGS		(portasmNB_REGS_SAVED + 4)
-#define PORT_CONTEXT_lastIDX		((portasmNB_REGS_SAVED) + portasmADDITIONAL_CONTEXT_SIZE)
-
-/* used in assembler, as byte offsets from the start of the context */
-#define PORT_CONTEXT_xIDX(X)		(X) /* index into "raw" for register x? */
-#define PORT_CONTEXT_xOFFSET(X) 	(PORT_CONTEXT_xIDX(X)		* portWORD_SIZE)
-#define PORT_CONTEXT_mepcOFFSET     (PORT_CONTEXT_mepcIDX		* portWORD_SIZE)
-#define PORT_CONTEXT_mstatusOFFSET  (PORT_CONTEXT_mstatusIDX	* portWORD_SIZE)
-#define PORT_CONTEXT_rufOFFSET   	(PORT_CONTEXT_rufIDX		* portWORD_SIZE)
-#define PORT_CONTEXT_fpuOFFSET(X) 	((X) 						* portFPUWORD_SIZE)
-/* total size of the structure usable in ASM. */
-
-#define portasmREGISTER_CONTEXT_WORDSIZE		((portasmLAST_BASE_REGS) * (portWORD_SIZE))
-#define portasmADDITIONAL_CONTEXT_WORDSIZE		((portasmADDITIONAL_CONTEXT_SIZE) * (portWORD_SIZE))
-#define portasmFPU_CONTEXT_WORDSIZE				((portasmFPU_CONTEXT_SIZE) * (portFPUWORD_SIZE))
+/* Only the standard core registers are stored by default.  Any additional
+registers must be saved by the portasmSAVE_ADDITIONAL_REGISTERS and
+portasmRESTORE_ADDITIONAL_REGISTERS macros - which can be defined in a chip
+specific version of freertos_risc_v_chip_specific_extensions.h.  See the notes
+at the top of this file. */
+#define portCONTEXT_SIZE ( 30 * portWORD_SIZE )
 
 .global xPortStartFirstTask
 .global freertos_risc_v_trap_handler
@@ -178,422 +112,184 @@ definitions. */
 .extern pullNextTime
 .extern uxTimerIncrementsForOneTick /* size_t type so 32-bit on 32-bit core and 64-bits on 64-bit core. */
 .extern xISRStackTop
-.extern portHANDLE_INTERRUPT
-.extern portHANDLE_EXCEPTION
-/*-----------------------------------------------------------*/
- 
-#ifdef __riscv_fdiv
-.macro portSAVE_FpuReg
-	/* get FS field from mstatus */
-	li t0, MSTATUS_FS
-	csrr 	t1, mstatus
-	and t0, t1, t0
-	li t2, MSTATUS_FS_DIRTY
-	bne t2, t0, 1f
-	/* FS == dirty */
-	/* Make room for the additional FPU registers. */
-	addi sp, sp, -portasmFPU_CONTEXT_WORDSIZE
-	store_fpu  f0,  PORT_CONTEXT_fpuOFFSET(0)(sp)		/* f0(ft0)		FP temporary register */
-	store_fpu  f1,  PORT_CONTEXT_fpuOFFSET(1)(sp)		/* f1(ft1)		FP temporary register */
-	store_fpu  f2,  PORT_CONTEXT_fpuOFFSET(2)(sp)		/* f2(ft2)		FP temporary register */
-	store_fpu  f3,  PORT_CONTEXT_fpuOFFSET(3)(sp)		/* f3(ft3)		FP temporary register */
-	store_fpu  f4,  PORT_CONTEXT_fpuOFFSET(4)(sp)		/* f4(ft4)		FP temporary register */
-	store_fpu  f5,  PORT_CONTEXT_fpuOFFSET(5)(sp)		/* f5(ft5)		FP temporary register */
-	store_fpu  f6,  PORT_CONTEXT_fpuOFFSET(6)(sp)		/* f6(ft6)		FP temporary register */
-	store_fpu  f7,  PORT_CONTEXT_fpuOFFSET(7)(sp)		/* f7(ft7)		FP temporary register */
+.extern portasmHANDLE_INTERRUPT
 
-	store_fpu  f8,  PORT_CONTEXT_fpuOFFSET(8)(sp)		/* f8(fs0)		FP Saved register */
-	store_fpu  f9,  PORT_CONTEXT_fpuOFFSET(9)(sp)		/* f9(fs0)		FP Saved register */
-
-	store_fpu  f10,  PORT_CONTEXT_fpuOFFSET(10)(sp)	/* f10(fa0)		FP arguments/return values register */
-	store_fpu  f11,  PORT_CONTEXT_fpuOFFSET(11)(sp)	/* f11(fa1)		FP arguments/return values register */
-
-	store_fpu  f12,  PORT_CONTEXT_fpuOFFSET(12)(sp)	/* f12(fa2)		FP arguments register */
-	store_fpu  f13,  PORT_CONTEXT_fpuOFFSET(13)(sp)	/* f13(fa3)		FP arguments register */
-	store_fpu  f14,  PORT_CONTEXT_fpuOFFSET(14)(sp)	/* f14(fa4)		FP arguments register */
-	store_fpu  f15,  PORT_CONTEXT_fpuOFFSET(15)(sp)	/* f15(fa5)		FP arguments register */
-	store_fpu  f16,  PORT_CONTEXT_fpuOFFSET(16)(sp)	/* f16(fa6)		FP arguments register */
-	store_fpu  f17,  PORT_CONTEXT_fpuOFFSET(17)(sp)	/* f17(fa7)		FP arguments register */
-
-	store_fpu  f18,  PORT_CONTEXT_fpuOFFSET(18)(sp)	/* f18(fs2)		FP Saved register */
-	store_fpu  f19,  PORT_CONTEXT_fpuOFFSET(19)(sp)	/* f19(fs3)		FP Saved register */
-	store_fpu  f20,  PORT_CONTEXT_fpuOFFSET(20)(sp)	/* f20(fs4)		FP Saved register */
-	store_fpu  f21,  PORT_CONTEXT_fpuOFFSET(21)(sp)	/* f21(fs5)		FP Saved register */
-	store_fpu  f22,  PORT_CONTEXT_fpuOFFSET(22)(sp)	/* f22(fs6)		FP Saved register */
-	store_fpu  f23,  PORT_CONTEXT_fpuOFFSET(23)(sp)	/* f23(fs7)		FP Saved register */
-	store_fpu  f24,  PORT_CONTEXT_fpuOFFSET(24)(sp)	/* f24(fs8)		FP Saved register */
-	store_fpu  f25,  PORT_CONTEXT_fpuOFFSET(25)(sp)	/* f25(fs9)		FP Saved register */
-	store_fpu  f26,  PORT_CONTEXT_fpuOFFSET(26)(sp)	/* f26(fs10)	FP Saved register */
-	store_fpu  f27,  PORT_CONTEXT_fpuOFFSET(27)(sp)	/* f27(fs11)	FP Saved register */
-
-	store_fpu  f28,  PORT_CONTEXT_fpuOFFSET(28)(sp)	/* f28(ft8)		FP temporary register */
-	store_fpu  f29,  PORT_CONTEXT_fpuOFFSET(29)(sp)	/* f29(ft9)		FP temporary register */
-	store_fpu  f30,  PORT_CONTEXT_fpuOFFSET(30)(sp)	/* f30(ft10)	FP temporary register */
-	store_fpu  f31,  PORT_CONTEXT_fpuOFFSET(31)(sp)	/* f31(ft11)	FP temporary register */
-
-	/* must set FS to clean */
-	csrc 	mstatus, t0
-	li 	t1, MSTATUS_FS_CLEAN
-	csrs	mstatus, t1
-1:
-	.endm
-#else
-.macro portSAVE_FpuReg
-	/* No fpu registers to save, so this macro does nothing. */
-	.endm
-#endif /* __riscv_fdiv */
-/*-----------------------------------------------------------*/
-
-#ifdef __riscv_fdiv
-.macro portRESTORE_FpuReg
-	/* get FS field from mstatus */
-	li t0, MSTATUS_FS
-	csrr 	t1, mstatus
-	and t0, t1, t0
-	li t2, MSTATUS_FS_OFF
-	beq t2, t0, 1f
-	/* FS != off */
-	csrs mstatus, t0
-	/* Remove space added for additional fpu registers. */
-	addi sp, sp, portasmFPU_CONTEXT_WORDSIZE
-	load_fpu  f0,  PORT_CONTEXT_fpuOFFSET(0)(sp)		/* f0(ft0)		FP temporary register */
-	load_fpu  f1,  PORT_CONTEXT_fpuOFFSET(1)(sp)		/* f1(ft1)		FP temporary register */
-	load_fpu  f2,  PORT_CONTEXT_fpuOFFSET(2)(sp)		/* f2(ft2)		FP temporary register */
-	load_fpu  f3,  PORT_CONTEXT_fpuOFFSET(3)(sp)		/* f3(ft3)		FP temporary register */
-	load_fpu  f4,  PORT_CONTEXT_fpuOFFSET(4)(sp)		/* f4(ft4)		FP temporary register */
-	load_fpu  f5,  PORT_CONTEXT_fpuOFFSET(5)(sp)		/* f5(ft5)		FP temporary register */
-	load_fpu  f6,  PORT_CONTEXT_fpuOFFSET(6)(sp)		/* f6(ft6)		FP temporary register */
-	load_fpu  f7,  PORT_CONTEXT_fpuOFFSET(7)(sp)		/* f7(ft7)		FP temporary register */
-
-	load_fpu  f8,  PORT_CONTEXT_fpuOFFSET(8)(sp)		/* f8(fs0)		FP Saved register */
-	load_fpu  f9,  PORT_CONTEXT_fpuOFFSET(9)(sp)		/* f9(fs0)		FP Saved register */
-
-	load_fpu  f10,  PORT_CONTEXT_fpuOFFSET(10)(sp)	/* f10(fa0)		FP arguments/return values register */
-	load_fpu  f11,  PORT_CONTEXT_fpuOFFSET(11)(sp)	/* f11(fa1)		FP arguments/return values register */
-
-	load_fpu  f12,  PORT_CONTEXT_fpuOFFSET(12)(sp)	/* f12(fa2)		FP arguments register */
-	load_fpu  f13,  PORT_CONTEXT_fpuOFFSET(13)(sp)	/* f13(fa3)		FP arguments register */
-	load_fpu  f14,  PORT_CONTEXT_fpuOFFSET(14)(sp)	/* f14(fa4)		FP arguments register */
-	load_fpu  f15,  PORT_CONTEXT_fpuOFFSET(15)(sp)	/* f15(fa5)		FP arguments register */
-	load_fpu  f16,  PORT_CONTEXT_fpuOFFSET(16)(sp)	/* f16(fa6)		FP arguments register */
-	load_fpu  f17,  PORT_CONTEXT_fpuOFFSET(17)(sp)	/* f17(fa7)		FP arguments register */
-
-	load_fpu  f18,  PORT_CONTEXT_fpuOFFSET(18)(sp)	/* f18(fs2)		FP Saved register */
-	load_fpu  f19,  PORT_CONTEXT_fpuOFFSET(19)(sp)	/* f19(fs3)		FP Saved register */
-	load_fpu  f20,  PORT_CONTEXT_fpuOFFSET(20)(sp)	/* f20(fs4)		FP Saved register */
-	load_fpu  f21,  PORT_CONTEXT_fpuOFFSET(21)(sp)	/* f21(fs5)		FP Saved register */
-	load_fpu  f22,  PORT_CONTEXT_fpuOFFSET(22)(sp)	/* f22(fs6)		FP Saved register */
-	load_fpu  f23,  PORT_CONTEXT_fpuOFFSET(23)(sp)	/* f23(fs7)		FP Saved register */
-	load_fpu  f24,  PORT_CONTEXT_fpuOFFSET(24)(sp)	/* f24(fs8)		FP Saved register */
-	load_fpu  f25,  PORT_CONTEXT_fpuOFFSET(25)(sp)	/* f25(fs9)		FP Saved register */
-	load_fpu  f26,  PORT_CONTEXT_fpuOFFSET(26)(sp)	/* f26(fs10)	FP Saved register */
-	load_fpu  f27,  PORT_CONTEXT_fpuOFFSET(27)(sp)	/* f27(fs11)	FP Saved register */
-
-	load_fpu  f28,  PORT_CONTEXT_fpuOFFSET(28)(sp)	/* f28(ft8)		FP temporary register */
-	load_fpu  f29,  PORT_CONTEXT_fpuOFFSET(29)(sp)	/* f29(ft9)		FP temporary register */
-	load_fpu  f30,  PORT_CONTEXT_fpuOFFSET(30)(sp)	/* f30(ft10)	FP temporary register */
-	load_fpu  f31,  PORT_CONTEXT_fpuOFFSET(31)(sp)	/* f31(ft11)	FP temporary register */
-
-	/* must set FS to clean */
-	csrc 	mstatus, t0
-	li 	t1, MSTATUS_FS_CLEAN
-	csrs	mstatus, t1
-1:
-	.endm
-#else
-.macro portRESTORE_FpuReg
-	/* No fpu registers to restore, so this macro does nothing. */
-	.endm
-#endif /* __riscv_fdiv */
-/*-----------------------------------------------------------*/
-
-.macro portSAVE_BaseReg
-	/* Make room for the registers. */
-	addi	sp, sp, -portasmREGISTER_CONTEXT_WORDSIZE
-    store_x  x1,  PORT_CONTEXT_xOFFSET(1)(sp)		/* x1(ra)		Return address */
-													/* x2(sp) ***** Should be save ouside this macro */
-    store_x  x3,  PORT_CONTEXT_xOFFSET(3)(sp)		/* x3(gp)		Global pointer */
-    store_x  x4,  PORT_CONTEXT_xOFFSET(4)(sp)		/* x4(tp)		Thread pointer */
-    store_x  x5,  PORT_CONTEXT_xOFFSET(5)(sp)		/* x5(t0)		Temporary register */
-    store_x  x6,  PORT_CONTEXT_xOFFSET(6)(sp)		/* x6(t1)		Temporary register*/
-    store_x  x7,  PORT_CONTEXT_xOFFSET(7)(sp)		/* x7(t2)		Temporary register */
-    store_x  x8,  PORT_CONTEXT_xOFFSET(8)(sp)		/* x8(s0/fp)	Saved register/Frame pointer */
-    store_x  x9,  PORT_CONTEXT_xOFFSET(9)(sp)		/* x9(s1)		Saved register */
-    store_x  x10, PORT_CONTEXT_xOFFSET(10)(sp)		/* x10(a0)		Function argument */
-    store_x  x11, PORT_CONTEXT_xOFFSET(11)(sp)		/* x11(a1)		Function argument */
-    store_x  x12, PORT_CONTEXT_xOFFSET(12)(sp)		/* x12(a2)		Function argument */
-    store_x  x13, PORT_CONTEXT_xOFFSET(13)(sp)		/* x13(a3)		Function argument */
-    store_x  x14, PORT_CONTEXT_xOFFSET(14)(sp)		/* x14(a4)		Function argument */
-    store_x  x15, PORT_CONTEXT_xOFFSET(15)(sp)		/* x15(a5)		Function argument */
-#ifndef __riscv_32e
-    store_x  x16, PORT_CONTEXT_xOFFSET(16)(sp)		/* x16(a6)		Function arguments */
-    store_x  x17, PORT_CONTEXT_xOFFSET(17)(sp)		/* x17(a7)		Function arguments */
-    store_x  x18, PORT_CONTEXT_xOFFSET(18)(sp)		/* x18(s2)		Saved register */
-    store_x  x19, PORT_CONTEXT_xOFFSET(19)(sp)		/* x19(s3)		Saved register */
-    store_x  x20, PORT_CONTEXT_xOFFSET(20)(sp)		/* x20(s4)		Saved register */
-    store_x  x21, PORT_CONTEXT_xOFFSET(21)(sp)		/* x21(s5)		Saved register */
-    store_x  x22, PORT_CONTEXT_xOFFSET(22)(sp)		/* x22(s6)		Saved register */
-    store_x  x23, PORT_CONTEXT_xOFFSET(23)(sp)		/* x23(s7)		Saved register */
-    store_x  x24, PORT_CONTEXT_xOFFSET(24)(sp)		/* x24(s8)		Saved register */
-    store_x  x25, PORT_CONTEXT_xOFFSET(25)(sp)		/* x25(s9)		Saved register */
-    store_x  x26, PORT_CONTEXT_xOFFSET(26)(sp)		/* x26(s10)		Saved register */
-    store_x  x27, PORT_CONTEXT_xOFFSET(27)(sp)		/* x27(s11)		Saved register */
-    store_x  x28, PORT_CONTEXT_xOFFSET(28)(sp)		/* x28(t3)		Temporary register */
-    store_x  x29, PORT_CONTEXT_xOFFSET(29)(sp)		/* x29(t4)		Temporary register */
-    store_x  x30, PORT_CONTEXT_xOFFSET(30)(sp)		/* x30(t5)		Temporary register */
-    store_x  x31, PORT_CONTEXT_xOFFSET(31)(sp)		/* x31(t6)		Temporary register */
-#endif /* __riscv_32e */
-	/* Save mcause, mepc & mstatus state */
-	csrr a4, mepc
-	csrr a5, mstatus		/* Required for MPIE bit. */
-	store_x a4, PORT_CONTEXT_mepcOFFSET(sp)
-	store_x a5, PORT_CONTEXT_mstatusOFFSET(sp)
-	.endm
-/*-----------------------------------------------------------*/
-
-.macro portRESTORE_BaseReg
-	/* Restore mepc & mstatus state */
-	load_x  t0, PORT_CONTEXT_mepcOFFSET(sp)
-	load_x  t1, PORT_CONTEXT_mstatusOFFSET(sp)
-	csrw	mepc, t0
-	csrw	mstatus, t1
-
-    load_x  x1,  PORT_CONTEXT_xOFFSET(1)(sp)		/* x1(ra)		Return address */
-													/* x2(sp) ***** Should be save ouside this macro */
-    load_x  x3,  PORT_CONTEXT_xOFFSET(3)(sp)		/* x3(gp)		Global pointer */
-    load_x  x4,  PORT_CONTEXT_xOFFSET(4)(sp)		/* x4(tp)		Thread pointer */
-    load_x  x5,  PORT_CONTEXT_xOFFSET(5)(sp)		/* x5(t0)		Temporary register */
-    load_x  x6,  PORT_CONTEXT_xOFFSET(6)(sp)		/* x6(t1)		Temporary register*/
-    load_x  x7,  PORT_CONTEXT_xOFFSET(7)(sp)		/* x7(t2)		Temporary register */
-    load_x  x8,  PORT_CONTEXT_xOFFSET(8)(sp)		/* x8(s0/fp)	Saved register/Frame pointer */
-    load_x  x9,  PORT_CONTEXT_xOFFSET(9)(sp)		/* x9(s1)		Saved register */
-    load_x  x10, PORT_CONTEXT_xOFFSET(10)(sp)		/* x10(a0)		Function argument */
-    load_x  x11, PORT_CONTEXT_xOFFSET(11)(sp)		/* x11(a1)		Function argument */
-    load_x  x12, PORT_CONTEXT_xOFFSET(12)(sp)		/* x12(a2)		Function argument */
-    load_x  x13, PORT_CONTEXT_xOFFSET(13)(sp)		/* x13(a3)		Function argument */
-    load_x  x14, PORT_CONTEXT_xOFFSET(14)(sp)		/* x14(a4)		Function argument */
-    load_x  x15, PORT_CONTEXT_xOFFSET(15)(sp)		/* x15(a5)		Function argument */
-#ifndef __riscv_32e
-    load_x  x16, PORT_CONTEXT_xOFFSET(16)(sp)		/* x16(a6)		Function arguments */
-    load_x  x17, PORT_CONTEXT_xOFFSET(17)(sp)		/* x17(a7)		Function arguments */
-    load_x  x18, PORT_CONTEXT_xOFFSET(18)(sp)		/* x18(s2)		Saved register */
-    load_x  x19, PORT_CONTEXT_xOFFSET(19)(sp)		/* x19(s3)		Saved register */
-    load_x  x20, PORT_CONTEXT_xOFFSET(20)(sp)		/* x20(s4)		Saved register */
-    load_x  x21, PORT_CONTEXT_xOFFSET(21)(sp)		/* x21(s5)		Saved register */
-    load_x  x22, PORT_CONTEXT_xOFFSET(22)(sp)		/* x22(s6)		Saved register */
-    load_x  x23, PORT_CONTEXT_xOFFSET(23)(sp)		/* x23(s7)		Saved register */
-    load_x  x24, PORT_CONTEXT_xOFFSET(24)(sp)		/* x24(s8)		Saved register */
-    load_x  x25, PORT_CONTEXT_xOFFSET(25)(sp)		/* x25(s9)		Saved register */
-    load_x  x26, PORT_CONTEXT_xOFFSET(26)(sp)		/* x26(s10)		Saved register */
-    load_x  x27, PORT_CONTEXT_xOFFSET(27)(sp)		/* x27(s11)		Saved register */
-    load_x  x28, PORT_CONTEXT_xOFFSET(28)(sp)		/* x28(t3)		Temporary register */
-    load_x  x29, PORT_CONTEXT_xOFFSET(29)(sp)		/* x29(t4)		Temporary register */
-    load_x  x30, PORT_CONTEXT_xOFFSET(30)(sp)		/* x30(t5)		Temporary register */
-    load_x  x31, PORT_CONTEXT_xOFFSET(31)(sp)		/* x31(t6)		Temporary register */
-#endif /* __riscv_32e */
-	.endm
 /*-----------------------------------------------------------*/
 
 .align 8
 .func
 freertos_risc_v_trap_handler:
-	/* We do not know if this is an ASYNC or SYNC
-	 * If ASYNC, it is a normal interrupt
-	 *  and the stack pointer is assumed good.
-	 * else (SYNC)
-	 *  We could be here due to a bus fault.
-	 */
-    csrw	mscratch, t0
-    csrr	t0, mcause
-    blt  	t0, x0, handle_interrupt
+	addi sp, sp, -portCONTEXT_SIZE
+	store_x x1, 1 * portWORD_SIZE( sp )
+	store_x x5, 2 * portWORD_SIZE( sp )
+	store_x x6, 3 * portWORD_SIZE( sp )
+	store_x x7, 4 * portWORD_SIZE( sp )
+	store_x x8, 5 * portWORD_SIZE( sp )
+	store_x x9, 6 * portWORD_SIZE( sp )
+	store_x x10, 7 * portWORD_SIZE( sp )
+	store_x x11, 8 * portWORD_SIZE( sp )
+	store_x x12, 9 * portWORD_SIZE( sp )
+	store_x x13, 10 * portWORD_SIZE( sp )
+	store_x x14, 11 * portWORD_SIZE( sp )
+	store_x x15, 12 * portWORD_SIZE( sp )
+	store_x x16, 13 * portWORD_SIZE( sp )
+	store_x x17, 14 * portWORD_SIZE( sp )
+	store_x x18, 15 * portWORD_SIZE( sp )
+	store_x x19, 16 * portWORD_SIZE( sp )
+	store_x x20, 17 * portWORD_SIZE( sp )
+	store_x x21, 18 * portWORD_SIZE( sp )
+	store_x x22, 19 * portWORD_SIZE( sp )
+	store_x x23, 20 * portWORD_SIZE( sp )
+	store_x x24, 21 * portWORD_SIZE( sp )
+	store_x x25, 22 * portWORD_SIZE( sp )
+	store_x x26, 23 * portWORD_SIZE( sp )
+	store_x x27, 24 * portWORD_SIZE( sp )
+	store_x x28, 25 * portWORD_SIZE( sp )
+	store_x x29, 26 * portWORD_SIZE( sp )
+	store_x x30, 27 * portWORD_SIZE( sp )
+	store_x x31, 28 * portWORD_SIZE( sp )
 
-handle_exception:
-	/* mscratch = old t0
-	 * t0 = mcause
-	 * mcause = small number 0..16
-	 *  0 Instruction address misaligned
-	 *  1 Instruction access fault
-	 *  2 Illegal instruction
-	 *  3 Breakpoint
-	 *  4 Load address misaligned
-	 *  5 Load access fault
-	 *  6 Store/AMO address misaligned
-	 *  7 Store/AMO access fault
-	 *  8 Environment call from U-mode
-	 *  9 Environment call from S-mode
-	 *  10 Reserved
-	 *  11 Environment call from M-mode
-	 *  12 Instruction page fault
-	 *  13 Load page fault
-	 *  14 Reserved
-	 *  15 Store/AMO page fault
-	 *  ≥16 Reserved
-	 *
-	 * if( mcause between 8 and 11  ) we are good - ecall
-	 * else: problem
-	 */
+	csrr t0, mstatus					/* Required for MPIE bit. */
+	store_x t0, 29 * portWORD_SIZE( sp )
 
-	addi	t0, t0, -8
-	blt		t0, x0, is_exception /* mcause < 8, must be fault */
-	addi	t0, t0, -4
-	blt		t0, x0, ecall_yield
+	portasmSAVE_ADDITIONAL_REGISTERS	/* Defined in freertos_risc_v_chip_specific_extensions.h to save any registers unique to the RISC-V implementation. */
 
-is_exception:
-	/* restore t0 and save sp in mscratch. */
-	csrr	t0, mscratch
-	   csrw	mscratch, sp
-	/* Switch to ISR stack before function call. */
-	load_x	sp, xISRStackTop			
-	portSAVE_BaseReg
-	csrrw	t0, mscratch, t0
-	/* SP = X2, so save it */
-	store_x	t0, PORT_CONTEXT_xOFFSET(2)(sp)
-	/* Defined in freertos_risc_v_chip_specific_extensions.h to save any registers unique to the RISC-V implementation. */
-	portasmSAVE_ADDITIONAL_REGISTERS
-	/* Save any fpu registers */
-	portSAVE_FpuReg
-	/* Execption is treated by external function */
-	jal portHANDLE_EXCEPTION
-	/* in case that the go back from exception, restore registers */
-	portRESTORE_FpuReg
-	portasmRESTORE_ADDITIONAL_REGISTERS
-	portRESTORE_BaseReg
-	load_x  x2, PORT_CONTEXT_xOFFSET(2)(sp)
-	mret
- 
-ecall_yield:
-	portSAVE_BaseReg
-	/* a4 = mepc
-	 * a5 = mstatus
-	 * s0 will be use for pxCurrentTCB
-	 * s1 will be use to save sp
-	 */
-	/* Synchronous so updated exception return address to the instruction after the instruction that generated the exeption. */
-	addi	t0, a4, 4
-	store_x	t0, PORT_CONTEXT_mepcOFFSET(sp) 
-	/* Store the value of sp when the interrupt occur */
-	addi 	t0, sp, portasmREGISTER_CONTEXT_WORDSIZE
-	store_x t0, PORT_CONTEXT_xOFFSET(2)(sp)
+	load_x  t0, pxCurrentTCB			/* Load pxCurrentTCB. */
+	store_x  sp, 0( t0 )				/* Write sp to first TCB member. */
 
-	/* Defined in freertos_risc_v_chip_specific_extensions.h to save any registers unique to the RISC-V implementation. */
-	portasmSAVE_ADDITIONAL_REGISTERS
-	/* Save any fpu registers */
-	portSAVE_FpuReg
+	csrr a0, mcause
+	csrr a1, mepc
 
-	/* Load pxCurrentTCB and update first TCB member(pxTopOfStack) with sp. */
-	load_x  s0, pxCurrentTCB
-	store_x  sp, 0( s0 )
+test_if_asynchronous:
+	srli a2, a0, __riscv_xlen - 1		/* MSB of mcause is 1 if handing an asynchronous interrupt - shift to LSB to clear other bits. */
+	beq a2, x0, handle_synchronous		/* Branch past interrupt handing if not asynchronous. */
+	store_x a1, 0( sp )					/* Asynch so save unmodified exception return address. */
 
-	/* Save sp into s1 */
-	mv  s1, sp
-	load_x sp, xISRStackTop			/* Switch to ISR stack before function call. */
-
-	j	switch_context
-
-handle_interrupt:
-	portSAVE_BaseReg
-	/* a4 = mepc
-	 * a5 = mstatus
-	 * s0 will be use for pxCurrentTCB
-	 * s1 will be use to save sp
-	 */
-
-	/* Store the value of sp when the interrupt occur */
-	addi t0, sp, portasmREGISTER_CONTEXT_WORDSIZE
-	store_x  t0, PORT_CONTEXT_xOFFSET(2)(sp)
-
-	/* Defined in freertos_risc_v_chip_specific_extensions.h to save any registers unique to the RISC-V implementation. */
-	portasmSAVE_ADDITIONAL_REGISTERS
-	/* Save any fpu registers */
-	portSAVE_FpuReg
-
-	/* Load pxCurrentTCB and update first TCB member(pxTopOfStack) with sp. */
-	load_x  s0, pxCurrentTCB
-	store_x  sp, 0( s0 )
-
-	/* Save sp into s1 */
-	mv  s1, sp
-	load_x sp, xISRStackTop			/* Switch to ISR stack before function call. */
+handle_asynchronous:
 
 #if( portasmHAS_MTIME != 0 )
-	addi t0, x0, 1
 
-	slli t0, t0, __riscv_xlen - 1   /* LSB is already set, shift into MSB.  Shift 31 on 32-bit or 63 on 64-bit cores. */
-	addi t1, t0, 7					/* 0x8000[]0007 == machine timer interrupt. */
-    csrr t2, mcause
-	bne t2, t1, test_if_external_interrupt
+	test_if_mtimer:						/* If there is a CLINT then the mtimer is used to generate the tick interrupt. */
 
-	load_x t0, pullMachineTimerCompareRegister  /* Load address of compare register into t0. */
-	load_x t1, pullNextTime  		/* Load the address of ullNextTime into t1. */
+		addi t0, x0, 1
 
-	#if( __riscv_xlen == 32 )
-		/* Update the 64-bit mtimer compare match value in two 32-bit writes. */
-		lw 	a0, 0(t1)				/* Load the low word of ullNextTime into a0. */
-		lw 	a1, 4(t1)				/* Load the high word of ullNextTime into a1. */
-		li  t2, -1
-		sw 	t2, 4(t0)				/* Store low word of ullNextTime into compare register. */
-		sw 	a0, 0(t0)				/* Store low word of ullNextTime into compare register. */
-		sw 	a1, 4(t0)				/* Store high word of ullNextTime into compare register. */
-		lw 	t0, uxTimerIncrementsForOneTick	/* Load the value of ullTimerIncrementForOneTick into t0 (could this be optimized by storing in an array next to pullNextTime?). */
-		add a2, t0, a0				/* Add the low word of ullNextTime to the timer increments for one tick (assumes timer increment for one tick fits in 32-bits). */
-		sltu t2, a2, a0				/* See if the sum of low words overflowed (what about the zero case?). */
-		add a3, a1, t2				/* Add overflow to high word of ullNextTime. */
-		sw 	a2, 0(t1)				/* Store new low word of ullNextTime. */
-		sw 	a3, 4(t1)				/* Store new high word of ullNextTime. */
-	#endif /* ( __riscv_xlen == 32 ) */
-	#if( __riscv_xlen == 64 )
-		/* Update the 64-bit mtimer compare match value. */
-		ld 	a0, 0(t1)			 	/* Load ullNextTime into a0. */
-		sd 	a0, 0(t0)				/* Store ullNextTime into compare register. */
-		ld 	t0, uxTimerIncrementsForOneTick  /* Load the value of ullTimerIncrementForOneTick into t0 (could this be optimized by storing in an array next to pullNextTime?). */
-		add 	a2, t0, a0				/* Add ullNextTime to the timer increments for one tick. */
-		sd 	a2, 0(t1)				/* Store ullNextTime. */
-	#endif /* ( __riscv_xlen == 64 ) */
+		slli t0, t0, __riscv_xlen - 1   /* LSB is already set, shift into MSB.  Shift 31 on 32-bit or 63 on 64-bit cores. */
+		addi t1, t0, 7					/* 0x8000[]0007 == machine timer interrupt. */
+		bne a0, t1, test_if_external_interrupt
 
-	jal xTaskIncrementTick
-	beqz a0, restore_before_exit		/* Don't switch context if incrementing tick didn't unblock a task. */
-	j switch_context
+		load_x t0, pullMachineTimerCompareRegister  /* Load address of compare register into t0. */
+		load_x t1, pullNextTime  		/* Load the address of ullNextTime into t1. */
 
-restore_before_exit:
-	mv  sp, s1
-	j end_trap_handler
+		#if( __riscv_xlen == 32 )
 
-test_if_external_interrupt:			/* If there is a CLINT and the mtimer interrupt is not pending then check to see if an external interrupt is pending. */
-	addi t1, t1, 4					/* 0x80000007 + 4 = 0x8000000b == Machine external interrupt. */
-    csrr t2, mcause
-	bne t2, t1, unrecoverable_error	/* Something as yet unhandled. */
-	j unrecoverable_error
-#endif /* ( portasmHAS_MTIME != 0 ) */
+			/* Update the 64-bit mtimer compare match value in two 32-bit writes. */
+			li t4, -1
+			lw t2, 0(t1)				/* Load the low word of ullNextTime into t2. */
+			lw t3, 4(t1)				/* Load the high word of ullNextTime into t3. */
+			sw t4, 0(t0)				/* Low word no smaller than old value to start with - will be overwritten below. */
+			sw t3, 4(t0)				/* Store high word of ullNextTime into compare register.  No smaller than new value. */
+			sw t2, 0(t0)				/* Store low word of ullNextTime into compare register. */
+			lw t0, uxTimerIncrementsForOneTick	/* Load the value of ullTimerIncrementForOneTick into t0 (could this be optimized by storing in an array next to pullNextTime?). */
+			add t4, t0, t2				/* Add the low word of ullNextTime to the timer increments for one tick (assumes timer increment for one tick fits in 32-bits). */
+			sltu t5, t4, t2				/* See if the sum of low words overflowed (what about the zero case?). */
+			add t6, t3, t5				/* Add overflow to high word of ullNextTime. */
+			sw t4, 0(t1)				/* Store new low word of ullNextTime. */
+			sw t6, 4(t1)				/* Store new high word of ullNextTime. */
 
-external_interrupt:
-	/* Switch to ISR stack before function call. */
-	load_x sp, xISRStackTop
-	jal portHANDLE_INTERRUPT
-	mv	sp, s1
-	j end_trap_handler
+		#endif /* __riscv_xlen == 32 */
 
-unrecoverable_error:
-    csrr 	t0, mcause              /* For viewing in the debugger only. */
-    csrr	t1, mepc                /* For viewing in the debugger only. */
-    csrr 	t2, mstatus
-	wfi
-	j unrecoverable_error
+		#if( __riscv_xlen == 64 )
 
-switch_context:
-	jal	vTaskSwitchContext
-	load_x s0, pxCurrentTCB			/* Load pxCurrentTCB. */
-	load_x  sp, 0( s0 )				/* Read sp from first TCB member. */
+			/* Update the 64-bit mtimer compare match value. */
+			ld t2, 0(t1)			 	/* Load ullNextTime into t2. */
+			sd t2, 0(t0)				/* Store ullNextTime into compare register. */
+			ld t0, uxTimerIncrementsForOneTick  /* Load the value of ullTimerIncrementForOneTick into t0 (could this be optimized by storing in an array next to pullNextTime?). */
+			add t4, t0, t2				/* Add ullNextTime to the timer increments for one tick. */
+			sd t4, 0(t1)				/* Store ullNextTime. */
 
-end_trap_handler:	
-	load_x s0, pxCurrentTCB			/* Load pxCurrentTCB. */
-	load_x  t1, PORT_CONTEXT_xOFFSET(2)(sp)
-	store_x  t1, 0( s0 )			/* Write sp saved value to first TCB member. */
+		#endif /* __riscv_xlen == 64 */
+
+		load_x sp, xISRStackTop			/* Switch to ISR stack before function call. */
+		jal xTaskIncrementTick
+		beqz a0, processed_source		/* Don't switch context if incrementing tick didn't unblock a task. */
+		jal vTaskSwitchContext
+		j processed_source
+
+	test_if_external_interrupt:			/* If there is a CLINT and the mtimer interrupt is not pending then check to see if an external interrupt is pending. */
+		addi t1, t1, 4					/* 0x80000007 + 4 = 0x8000000b == Machine external interrupt. */
+		bne a0, t1, as_yet_unhandled	/* Something as yet unhandled. */
+
+#endif /* portasmHAS_MTIME */
+
+	load_x sp, xISRStackTop				/* Switch to ISR stack before function call. */
+	jal portasmHANDLE_INTERRUPT			/* Jump to the interrupt handler if there is no CLINT or if there is a CLINT and it has been determined that an external interrupt is pending. */
+	j processed_source
+
+handle_synchronous:
+	addi a1, a1, 4						/* Synchronous so updated exception return address to the instruction after the instruction that generated the exeption. */
+	store_x a1, 0( sp )					/* Save updated exception return address. */
+
+test_if_environment_call:
+	li t0, 11 							/* 11 == environment call. */
+	bne a0, t0, is_exception			/* Not an M environment call, so some other exception. */
+	load_x sp, xISRStackTop				/* Switch to ISR stack before function call. */
+	jal vTaskSwitchContext
+	j processed_source
+
+is_exception:
+	csrr t0, mcause						/* For viewing in the debugger only. */
+	csrr t1, mepc						/* For viewing in the debugger only */
+	csrr t2, mstatus
+	j is_exception						/* No other exceptions handled yet. */
+
+as_yet_unhandled:
+	csrr t0, mcause						/* For viewing in the debugger only. */
+	j as_yet_unhandled
+
+processed_source:
+	load_x  t1, pxCurrentTCB			/* Load pxCurrentTCB. */
+	load_x  sp, 0( t1 )				 	/* Read sp from first TCB member. */
+
+	/* Load mret with the address of the next instruction in the task to run next. */
+	load_x t0, 0( sp )
+	csrw mepc, t0
+
+	portasmRESTORE_ADDITIONAL_REGISTERS	/* Defined in freertos_risc_v_chip_specific_extensions.h to restore any registers unique to the RISC-V implementation. */
+
+	/* Load mstatus with the interrupt enable bits used by the task. */
+	load_x  t0, 29 * portWORD_SIZE( sp )
+	csrw mstatus, t0						/* Required for MPIE bit. */
+
+	load_x  x1, 1 * portWORD_SIZE( sp )
+	load_x  x5, 2 * portWORD_SIZE( sp )		/* t0 */
+	load_x  x6, 3 * portWORD_SIZE( sp )		/* t1 */
+	load_x  x7, 4 * portWORD_SIZE( sp )		/* t2 */
+	load_x  x8, 5 * portWORD_SIZE( sp )		/* s0/fp */
+	load_x  x9, 6 * portWORD_SIZE( sp )		/* s1 */
+	load_x  x10, 7 * portWORD_SIZE( sp )	/* a0 */
+	load_x  x11, 8 * portWORD_SIZE( sp )	/* a1 */
+	load_x  x12, 9 * portWORD_SIZE( sp )	/* a2 */
+	load_x  x13, 10 * portWORD_SIZE( sp )	/* a3 */
+	load_x  x14, 11 * portWORD_SIZE( sp )	/* a4 */
+	load_x  x15, 12 * portWORD_SIZE( sp )	/* a5 */
+	load_x  x16, 13 * portWORD_SIZE( sp )	/* a6 */
+	load_x  x17, 14 * portWORD_SIZE( sp )	/* a7 */
+	load_x  x18, 15 * portWORD_SIZE( sp )	/* s2 */
+	load_x  x19, 16 * portWORD_SIZE( sp )	/* s3 */
+	load_x  x20, 17 * portWORD_SIZE( sp )	/* s4 */
+	load_x  x21, 18 * portWORD_SIZE( sp )	/* s5 */
+	load_x  x22, 19 * portWORD_SIZE( sp )	/* s6 */
+	load_x  x23, 20 * portWORD_SIZE( sp )	/* s7 */
+	load_x  x24, 21 * portWORD_SIZE( sp )	/* s8 */
+	load_x  x25, 22 * portWORD_SIZE( sp )	/* s9 */
+	load_x  x26, 23 * portWORD_SIZE( sp )	/* s10 */
+	load_x  x27, 24 * portWORD_SIZE( sp )	/* s11 */
+	load_x  x28, 25 * portWORD_SIZE( sp )	/* t3 */
+	load_x  x29, 26 * portWORD_SIZE( sp )	/* t4 */
+	load_x  x30, 27 * portWORD_SIZE( sp )	/* t5 */
+	load_x  x31, 28 * portWORD_SIZE( sp )	/* t6 */
+	addi sp, sp, portCONTEXT_SIZE
 
-	/* restore registers */
-	portRESTORE_FpuReg
-	portasmRESTORE_ADDITIONAL_REGISTERS
-	portRESTORE_BaseReg
-	load_x  x2, PORT_CONTEXT_xOFFSET(2)(sp)
 	mret
 	.endfunc
 /*-----------------------------------------------------------*/
@@ -608,37 +304,49 @@ xPortStartFirstTask:
 	outside of this file. */
 	la t0, freertos_risc_v_trap_handler
 	csrw mtvec, t0
-#endif /* ( portasmHAS_SIFIVE_CLINT != 0 ) */
+#endif /* portasmHAS_CLILNT */
 
-	/** Set all register to the FirstTask context */
-	load_x  t2, pxCurrentTCB			/* Load pxCurrentTCB. */
-	load_x  sp, 0( t2 )				 	/* Read sp from first TCB member. */
+	load_x  sp, pxCurrentTCB			/* Load pxCurrentTCB. */
+	load_x  sp, 0( sp )				 	/* Read sp from first TCB member. */
 
-	/* Restore first TCB member */
-	load_x  t1,  PORT_CONTEXT_xOFFSET(2)(sp)
-	store_x  t1, 0( t2 )				/* Write sp saved value to first TCB member. */
+	load_x  x1, 0( sp ) /* Note for starting the scheduler the exception return address is used as the function return address. */
 
-	/* enable interrupt */
-    #if( portasmHAS_MTIME != 0 )
-	    li t0, 0x880
-	    csrs mie, t0
-    #else
-	    li t0, 0x800
-	    csrs mie, t0
-    #endif /* ( portasmHAS_MTIME != 0 ) */
+	portasmRESTORE_ADDITIONAL_REGISTERS	/* Defined in freertos_risc_v_chip_specific_extensions.h to restore any registers unique to the RISC-V implementation. */
 
-	portRESTORE_FpuReg
-	portasmRESTORE_ADDITIONAL_REGISTERS
-	/* Set MIE bit so the first task starts with interrupts enabled - required as returns with ret not eret. */
-	load_x  t1, PORT_CONTEXT_mstatusOFFSET(sp)
-	addi	t1, t1, 0x08				
-	store_x t1, PORT_CONTEXT_mstatusOFFSET(sp)
+	load_x  x6, 3 * portWORD_SIZE( sp )		/* t1 */
+	load_x  x7, 4 * portWORD_SIZE( sp )		/* t2 */
+	load_x  x8, 5 * portWORD_SIZE( sp )		/* s0/fp */
+	load_x  x9, 6 * portWORD_SIZE( sp )		/* s1 */
+	load_x  x10, 7 * portWORD_SIZE( sp )	/* a0 */
+	load_x  x11, 8 * portWORD_SIZE( sp )	/* a1 */
+	load_x  x12, 9 * portWORD_SIZE( sp )	/* a2 */
+	load_x  x13, 10 * portWORD_SIZE( sp )	/* a3 */
+	load_x  x14, 11 * portWORD_SIZE( sp )	/* a4 */
+	load_x  x15, 12 * portWORD_SIZE( sp )	/* a5 */
+	load_x  x16, 13 * portWORD_SIZE( sp )	/* a6 */
+	load_x  x17, 14 * portWORD_SIZE( sp )	/* a7 */
+	load_x  x18, 15 * portWORD_SIZE( sp )	/* s2 */
+	load_x  x19, 16 * portWORD_SIZE( sp )	/* s3 */
+	load_x  x20, 17 * portWORD_SIZE( sp )	/* s4 */
+	load_x  x21, 18 * portWORD_SIZE( sp )	/* s5 */
+	load_x  x22, 19 * portWORD_SIZE( sp )	/* s6 */
+	load_x  x23, 20 * portWORD_SIZE( sp )	/* s7 */
+	load_x  x24, 21 * portWORD_SIZE( sp )	/* s8 */
+	load_x  x25, 22 * portWORD_SIZE( sp )	/* s9 */
+	load_x  x26, 23 * portWORD_SIZE( sp )	/* s10 */
+	load_x  x27, 24 * portWORD_SIZE( sp )	/* s11 */
+	load_x  x28, 25 * portWORD_SIZE( sp )	/* t3 */
+	load_x  x29, 26 * portWORD_SIZE( sp )	/* t4 */
+	load_x  x30, 27 * portWORD_SIZE( sp )	/* t5 */
+	load_x  x31, 28 * portWORD_SIZE( sp )	/* t6 */
 
-	portRESTORE_BaseReg
+	load_x  x5, 29 * portWORD_SIZE( sp )	/* Initial mstatus into x5 (t0) */
+	addi x5, x5, 0x08						/* Set MIE bit so the first task starts with interrupts enabled - required as returns with ret not eret. */
+	csrrw  x0, mstatus, x5					/* Interrupts enabled from here! */
+	load_x  x5, 2 * portWORD_SIZE( sp )		/* Initial x5 (t0) value. */
 
-	load_x  ra, PORT_CONTEXT_mepcOFFSET(sp) /* Note for starting the scheduler the exception return address is used as the function return address. */
-	load_x  x2, PORT_CONTEXT_xOFFSET(2)(sp)
-	mret
+	addi	sp, sp, portCONTEXT_SIZE
+	ret
 	.endfunc
 /*-----------------------------------------------------------*/
 
@@ -652,7 +360,7 @@ xPortStartFirstTask:
  * a1, and pvParameters in a2.  The new top of stack is passed out in a0.
  *
  * RISC-V maps registers to ABI names as follows (X1 to X31 integer registers
- * for the 'I' profile, X1 to X15 for the 'E' profile).
+ * for the 'I' profile, X1 to X15 for the 'E' profile, currently I assumed).
  *
  * Register		ABI Name	Description						Saver
  * x0			zero		Hard-wired zero					-
@@ -671,44 +379,36 @@ xPortStartFirstTask:
  * The RISC-V context is saved t FreeRTOS tasks in the following stack frame,
  * where the global and thread pointers are currently assumed to be constant so
  * are not saved:
- * The RISC-V context is saved t FreeRTOS tasks in the following stack frame:
  *
- * ruf (in order to be 16 bytes aligned)
- * ruf (in order to be 16 bytes aligned)
- * pxCode - mepc
  * mstatus
- * x31 (Only for 'I' profile)
- * x30 (Only for 'I' profile)
- * x29 (Only for 'I' profile)
- * x28 (Only for 'I' profile)
- * x27 (Only for 'I' profile)
- * x26 (Only for 'I' profile)
- * x25 (Only for 'I' profile)
- * x24 (Only for 'I' profile)
- * x23 (Only for 'I' profile)
- * x22 (Only for 'I' profile)
- * x21 (Only for 'I' profile)
- * x20 (Only for 'I' profile)
- * x19 (Only for 'I' profile)
- * x18 (Only for 'I' profile)
- * x17 (Only for 'I' profile)
- * x16 (Only for 'I' profile)
+ * x31
+ * x30
+ * x29
+ * x28
+ * x27
+ * x26
+ * x25
+ * x24
+ * x23
+ * x22
+ * x21
+ * x20
+ * x19
+ * x18
+ * x17
+ * x16
  * x15
  * x14
  * x13
  * x12
  * x11
- * pvParameters - x10 (a0)
+ * pvParameters
  * x9
  * x8
  * x7
  * x6
  * x5
- * x4 (tp)
- * x3 (gp)
- * x2 (sp)
- * portTASK_RETURN_ADDRESS - x1 (ra)
- * x0
+ * portTASK_RETURN_ADDRESS
  * [chip specific registers go here]
  * pxCode
  */
@@ -720,75 +420,24 @@ pxPortInitialiseStack:
 	andi t0, t0, ~0x8					/* Ensure interrupts are disabled when the stack is restored within an ISR.  Required when a task is created after the schedulre has been started, otherwise interrupts would be disabled anyway. */
 	addi t1, x0, 0x188					/* Generate the value 0x1880, which are the MPIE and MPP bits to set in mstatus. */
 	slli t1, t1, 4
-	not t2, t1							/* reset previous value */
-	and t0, t0, t2
 	or t0, t0, t1						/* Set MPIE and MPP bits in mstatus value. */
 
-	/* Make room for the registers. */
-	addi	t2, a0, -portasmREGISTER_CONTEXT_WORDSIZE
-	
-	store_x  x0,  PORT_CONTEXT_xOFFSET(1)(t2)	/* x1(ra)		Return address */
-	store_x  a0,  PORT_CONTEXT_xOFFSET(2)(t2)	/* x2(sp) 		Stack pointer */
-	store_x  x3,  PORT_CONTEXT_xOFFSET(3)(t2)	/* x3(gp)		Global pointer */
-	store_x  x4,  PORT_CONTEXT_xOFFSET(4)(t2)	/* x4(tp)		Thread pointer */
-	store_x  x0,  PORT_CONTEXT_xOFFSET(5)(t2)	/* x5(t0)		Temporaries */
-	store_x  x0,  PORT_CONTEXT_xOFFSET(6)(t2)	/* x6(t1)		Temporaries */
-	store_x  x0,  PORT_CONTEXT_xOFFSET(7)(t2)	/* x7(t2)		Temporaries */
-	store_x  x0,  PORT_CONTEXT_xOFFSET(8)(t2)	/* x8(s0/fp)	Saved register/Frame pointer */
-	store_x  x0,  PORT_CONTEXT_xOFFSET(9)(t2)	/* x9(s1)		Saved register */
-	store_x  a2, PORT_CONTEXT_xOFFSET(10)(t2)	/* x10(a0)		Function arguments */
-	store_x  x0, PORT_CONTEXT_xOFFSET(11)(t2)	/* x11(a1)		Function arguments */
-	store_x  x0, PORT_CONTEXT_xOFFSET(12)(t2)	/* x12(a2)		Function arguments */
-	store_x  x0, PORT_CONTEXT_xOFFSET(13)(t2)	/* x13(a3)		Function arguments */
-	store_x  x0, PORT_CONTEXT_xOFFSET(14)(t2)	/* x14(a4)		Function arguments */
-	store_x  x0, PORT_CONTEXT_xOFFSET(15)(t2)	/* x15(a5)		Function arguments */
-#ifndef __riscv_32e
-	store_x  x0, PORT_CONTEXT_xOFFSET(16)(t2)	/* x16(a6)		Function arguments */
-	store_x  x0, PORT_CONTEXT_xOFFSET(17)(t2)	/* x17(a7)		Function arguments */
-	store_x  x0, PORT_CONTEXT_xOFFSET(18)(t2)	/* x18(s2)		Saved registers */
-	store_x  x0, PORT_CONTEXT_xOFFSET(19)(t2)	/* x19(s3)		Saved registers */
-	store_x  x0, PORT_CONTEXT_xOFFSET(20)(t2)	/* x20(s4)		Saved registers */
-	store_x  x0, PORT_CONTEXT_xOFFSET(21)(t2)	/* x21(s5)		Saved registers */
-	store_x  x0, PORT_CONTEXT_xOFFSET(22)(t2)	/* x22(s6)		Saved registers */
-	store_x  x0, PORT_CONTEXT_xOFFSET(23)(t2)	/* x23(s7)		Saved registers */
-	store_x  x0, PORT_CONTEXT_xOFFSET(24)(t2)	/* x24(s8)		Saved registers */
-	store_x  x0, PORT_CONTEXT_xOFFSET(25)(t2)	/* x25(s9)		Saved registers */
-	store_x  x0, PORT_CONTEXT_xOFFSET(26)(t2)	/* x26(s10)		Saved registers */
-	store_x  x0, PORT_CONTEXT_xOFFSET(27)(t2)	/* x27(s11)		Saved registers */
-	store_x  x0, PORT_CONTEXT_xOFFSET(28)(t2)	/* x28(t3)		Temporaries */
-	store_x  x0, PORT_CONTEXT_xOFFSET(29)(t2)	/* x29(t4)		Temporaries */
-	store_x  x0, PORT_CONTEXT_xOFFSET(30)(t2)	/* x30(t5)		Temporaries */
-	store_x  x0, PORT_CONTEXT_xOFFSET(31)(t2)	/* x31(t6)		Temporaries */
-#endif /* __riscv_32e */
-
-	store_x a1, PORT_CONTEXT_mepcOFFSET(t2)
-	store_x t0, PORT_CONTEXT_mstatusOFFSET(t2)
-
-	/* The number of additional registers. */
-	addi t0, x0, portasmADDITIONAL_CONTEXT_SIZE 
+	addi a0, a0, -portWORD_SIZE
+	store_x t0, 0(a0)					/* mstatus onto the stack. */
+	addi a0, a0, -(22 * portWORD_SIZE)	/* Space for registers x11-x31. */
+	store_x a2, 0(a0)					/* Task parameters (pvParameters parameter) goes into register X10/a0 on the stack. */
+	addi a0, a0, -(6 * portWORD_SIZE)	/* Space for registers x5-x9. */
+	store_x x0, 0(a0)					/* Return address onto the stack, could be portTASK_RETURN_ADDRESS */
+	addi t0, x0, portasmADDITIONAL_CONTEXT_SIZE /* The number of chip specific additional registers. */
 chip_specific_stack_frame:				/* First add any chip specific registers to the stack frame being created. */
 	beq t0, x0, 1f						/* No more chip specific registers to save. */
-	addi t2, t2, -portWORD_SIZE			/* Make space for chip specific register. */
-	store_x x0, 0(t2)					/* Give the chip specific register an initial value of zero. */
+	addi a0, a0, -portWORD_SIZE			/* Make space for chip specific register. */
+	store_x x0, 0(a0)					/* Give the chip specific register an initial value of zero. */
 	addi t0, t0, -1						/* Decrement the count of chip specific registers remaining. */
 	j chip_specific_stack_frame			/* Until no more chip specific registers. */
 1:
-
-	#ifdef __riscv_fdiv
-		/* Make room for the fpu registers. */
-		/* Here we use the memory space needed for all fpu registers instead of using the number of fpu registers */
-		/* Thanks to it we usually manage any xxbits core with yybits fpu */
-		addi t0, x0, portasmFPU_CONTEXT_WORDSIZE
-	fpu_specific_stack_frame:
-		beq t0, x0, 1f						/* No more space is needed. */
-		addi t2, t2, -portWORD_SIZE
-		store_x x0, 0(t2)					/* Give an initial value of zero. */
-		addi t0, t0, -portWORD_SIZE			/* Decrement the count space remaining. */
-		j fpu_specific_stack_frame			/* Until no more space is needed. */
-	1:	
-	#endif /* __riscv_fdiv */
-
-	mv a0, t2
+	addi a0, a0, -portWORD_SIZE
+	store_x a1, 0(a0)					/* mret value (pxCode parameter) onto the stack. */
 	ret
 	.endfunc
 /*-----------------------------------------------------------*/