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e-puertoe-puerto
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RISC-V: Add RV32E / FPU support for GCC (#140)
* Change vPortSetupTimerInterrupt in order to have 64bits access on rv64 * Support RV32E - RISC-V architecture (GCC) Signed-off-by: Emmanuel Puerto <emmanuel.puerto@sifive.com> * Support FPU - RISC-V architecture (GCC) Signed-off-by: Emmanuel Puerto <emmanuel.puerto@sifive.com> * Fix interrupt managment and FPU initialization
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‎portable/GCC/RISC-V/port.c‎

Lines changed: 91 additions & 46 deletions
Original file line numberDiff line numberDiff line change
@@ -25,9 +25,11 @@
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* 1 tab == 4 spaces!
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*/
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28-
/*-----------------------------------------------------------
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* Implementation of functions defined in portable.h for the RISC-V RV32 port.
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*----------------------------------------------------------*/
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/* ------------------------------------------------------------------
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* This file is part of the FreeRTOS distribution and was contributed
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* to the project by SiFive
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* ------------------------------------------------------------------
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*/
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/* Scheduler includes. */
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#include "FreeRTOS.h"
@@ -118,31 +120,69 @@ task stack, not the ISR stack). */
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119121
#if( configMTIME_BASE_ADDRESS != 0 ) && ( configMTIMECMP_BASE_ADDRESS != 0 )
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void vPortSetupTimerInterrupt( void )
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{
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uint32_t ulCurrentTimeHigh, ulCurrentTimeLow;
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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. */
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volatile uint32_t * const pulTimeLow = ( volatile uint32_t * const ) ( configMTIME_BASE_ADDRESS );
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volatile uint32_t ulHartId;
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__asm volatile( "csrr %0, mhartid" : "=r"( ulHartId ) );
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pullMachineTimerCompareRegister = ( volatile uint64_t * ) ( ullMachineTimerCompareRegisterBase + ( ulHartId * sizeof( uint64_t ) ) );
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do
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{
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ulCurrentTimeHigh = *pulTimeHigh;
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ulCurrentTimeLow = *pulTimeLow;
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} while( ulCurrentTimeHigh != *pulTimeHigh );
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ullNextTime = ( uint64_t ) ulCurrentTimeHigh;
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ullNextTime <<= 32ULL; /* High 4-byte word is 32-bits up. */
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ullNextTime |= ( uint64_t ) ulCurrentTimeLow;
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ullNextTime += ( uint64_t ) uxTimerIncrementsForOneTick;
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*pullMachineTimerCompareRegister = ullNextTime;
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/* Prepare the time to use after the next tick interrupt. */
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ullNextTime += ( uint64_t ) uxTimerIncrementsForOneTick;
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}
123+
#if( __riscv_xlen == 32 )
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void vPortSetupTimerInterrupt( void )
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{
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uint32_t ulCurrentTimeHigh, ulCurrentTimeLow;
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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. */
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volatile uint32_t * const pulTimeLow = ( volatile uint32_t * const ) ( configMTIME_BASE_ADDRESS );
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volatile uint32_t * pulTimeCompareRegisterHigh;
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volatile uint32_t * pulTimeCompareRegisterLow;
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volatile uint32_t ulHartId;
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__asm volatile ( "csrr %0, mhartid" : "=r" ( ulHartId ) );
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/* pullMachineTimerCompareRegister is used by freertos_risc_v_trap_handler */
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pullMachineTimerCompareRegister = ( volatile uint64_t * ) ( ullMachineTimerCompareRegisterBase + ( ulHartId * sizeof( uint64_t ) ) );
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pulTimeCompareRegisterLow = ( volatile uint32_t * ) ( ullMachineTimerCompareRegisterBase + ( ulHartId * sizeof( uint64_t ) ) );
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pulTimeCompareRegisterHigh = ( volatile uint32_t * ) ( ullMachineTimerCompareRegisterBase + ( ulHartId * sizeof( uint64_t ) ) + 4UL );
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do
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{
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ulCurrentTimeHigh = *pulTimeHigh;
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ulCurrentTimeLow = *pulTimeLow;
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} while( ulCurrentTimeHigh != *pulTimeHigh );
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ullNextTime = ( uint64_t ) ulCurrentTimeHigh;
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ullNextTime <<= 32ULL; /* High 4-byte word is 32-bits up. */
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ullNextTime |= (( uint64_t ) ulCurrentTimeLow );
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ullNextTime += (( uint64_t ) uxTimerIncrementsForOneTick );
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/* Per spec, the RISC-V MTIME/MTIMECMP registers are 64 bit,
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* and are NOT internally latched for multiword transfers.
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* Need to be careful about sequencing to avoid triggering
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* spurious interrupts: For that set the high word to a max
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* value first.
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*/
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*pulTimeCompareRegisterHigh = 0xFFFFFFFF;
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*pulTimeCompareRegisterLow = (uint32_t)( ullNextTime );
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*pulTimeCompareRegisterHigh = (uint32_t)( ullNextTime >> 32ULL );
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/* Prepare the time to use after the next tick interrupt. */
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ullNextTime += ( uint64_t ) uxTimerIncrementsForOneTick;
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}
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#endif /* __riscv_xlen == 32 */
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#if( __riscv_xlen == 64 )
167+
void vPortSetupTimerInterrupt( void )
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{
169+
volatile uint32_t * const pulTime = ( volatile uint32_t * const ) ( configMTIME_BASE_ADDRESS );
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volatile uint32_t ulHartId;
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173+
__asm volatile ( "csrr %0, mhartid" : "=r" ( ulHartId ) );
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175+
pullMachineTimerCompareRegister = ( volatile uint64_t * ) ( ullMachineTimerCompareRegisterBase + ( ulHartId * sizeof( uint64_t ) ) );
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ullNextTime = *pulTime;
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179+
ullNextTime += ( uint64_t ) uxTimerIncrementsForOneTick;
180+
*pullMachineTimerCompareRegister = ullNextTime;
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/* Prepare the time to use after the next tick interrupt. */
183+
ullNextTime += ( uint64_t ) uxTimerIncrementsForOneTick;
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}
185+
#endif /* __riscv_xlen == 64 */
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147187
#endif /* ( configMTIME_BASE_ADDRESS != 0 ) && ( configMTIME_BASE_ADDRESS != 0 ) */
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/*-----------------------------------------------------------*/
@@ -178,20 +218,7 @@ extern void xPortStartFirstTask( void );
178218
configure whichever clock is to be used to generate the tick interrupt. */
179219
vPortSetupTimerInterrupt();
180220

181-
#if( ( configMTIME_BASE_ADDRESS != 0 ) && ( configMTIMECMP_BASE_ADDRESS != 0 ) )
182-
{
183-
/* Enable mtime and external interrupts. 1<<7 for timer interrupt, 1<<11
184-
for external interrupt. _RB_ What happens here when mtime is not present as
185-
with pulpino? */
186-
__asm volatile( "csrs mie, %0" :: "r"(0x880) );
187-
}
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#else
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{
190-
/* Enable external interrupts. */
191-
__asm volatile( "csrs mie, %0" :: "r"(0x800) );
192-
}
193-
#endif /* ( configMTIME_BASE_ADDRESS != 0 ) && ( configMTIMECMP_BASE_ADDRESS != 0 ) */
194-
221+
/* Enabling mtime and external interrupts will be made into xPortStartFirstTask function */
195222
xPortStartFirstTask();
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197224
/* Should not get here as after calling xPortStartFirstTask() only tasks
@@ -205,8 +232,26 @@ void vPortEndScheduler( void )
205232
/* Not implemented. */
206233
for( ;; );
207234
}
235+
/*-----------------------------------------------------------*/
208236

209-
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237+
#if( configENABLE_FPU == 1 )
238+
void vPortSetupFPU( void )
239+
{
240+
#ifdef __riscv_fdiv
241+
__asm__ __volatile__ (
242+
"csrr t0, misa \n" /* Get misa */
243+
"li t1, 0x10028 \n" /* 0x10028 = Q,F,D Quad, Single or Double precission floating point */
244+
"and t0, t0, t1 \n"
245+
"beqz t0, 1f \n" /* check if Q,F or D is present into misa */
246+
"csrr t0, mstatus \n" /* Floating point unit is present so need to put it into initial state */
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"lui t1, 0x2 \n" /* t1 = 0x1 << 12 */
248+
"or t0, t0, t1 \n"
249+
"csrw mstatus, t0 \n" /* Set FS to initial state */
250+
"csrwi fcsr, 0 \n" /* Clear Floating-point Control and Status Register */
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"1: \n"
252+
:::
253+
);
254+
#endif /* __riscv_fdiv */
255+
}
256+
#endif /* configENABLE_FPU */
257+
/*-----------------------------------------------------------*/

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