mirror of
https://github.com/FreeRTOS/FreeRTOS-Kernel.git
synced 2025-09-12 09:07:46 -04:00
Support RV32E - RISC-V architecture (GCC)
Signed-off-by: Emmanuel Puerto <emmanuel.puerto@sifive.com>
This commit is contained in:
Emmanuel Puerto
parent
37f1d57f0e
commit
2167df2446
2 changed files with 442 additions and 263 deletions
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@ -25,9 +25,11 @@
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* 1 tab == 4 spaces!
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* 1 tab == 4 spaces!
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*/
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*/
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/*-----------------------------------------------------------
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/* ------------------------------------------------------------------
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* Implementation of functions defined in portable.h for the RISC-V RV32 port.
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* This file is part of the FreeRTOS distribution and was contributed
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*----------------------------------------------------------*/
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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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/* Scheduler includes. */
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#include "FreeRTOS.h"
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#include "FreeRTOS.h"
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@ -215,20 +217,7 @@ extern void xPortStartFirstTask( void );
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configure whichever clock is to be used to generate the tick interrupt. */
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configure whichever clock is to be used to generate the tick interrupt. */
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vPortSetupTimerInterrupt();
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vPortSetupTimerInterrupt();
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#if( ( configMTIME_BASE_ADDRESS != 0 ) && ( configMTIMECMP_BASE_ADDRESS != 0 ) )
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/* Enabling mtime and external interrupts will be made into xPortStartFirstTask function */
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{
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/* Enable mtime and external interrupts. 1<<7 for timer interrupt, 1<<11
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for external interrupt. _RB_ What happens here when mtime is not present as
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with pulpino? */
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__asm volatile( "csrs mie, %0" :: "r"(0x880) );
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}
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#else
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{
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/* Enable external interrupts. */
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__asm volatile( "csrs mie, %0" :: "r"(0x800) );
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}
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#endif /* ( configMTIME_BASE_ADDRESS != 0 ) && ( configMTIMECMP_BASE_ADDRESS != 0 ) */
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xPortStartFirstTask();
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xPortStartFirstTask();
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/* Should not get here as after calling xPortStartFirstTask() only tasks
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/* Should not get here as after calling xPortStartFirstTask() only tasks
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@ -55,17 +55,35 @@
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* registers.
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* registers.
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*
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*
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*/
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*/
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#if __riscv_xlen == 64
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#define portWORD_SIZE 8
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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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#if( __riscv_xlen == 64 )
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#define store_x sd
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#define store_x sd
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#define load_x ld
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#define load_x ld
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#elif __riscv_xlen == 32
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#elif( __riscv_xlen == 32 )
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#define store_x sw
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#define store_x sw
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#define load_x lw
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#define load_x lw
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#define portWORD_SIZE 4
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#else
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#else
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#error Assembler did not define __riscv_xlen
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#error Assembler did not define __riscv_xlen
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#endif
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#endif /* ( __riscv_xlen == xx ) */
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/* Nb registers to save */
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#ifdef __riscv_32e
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#define portasmNB_REGS_SAVED (16)
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#else
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#define portasmNB_REGS_SAVED (32)
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#endif /* __riscv_32e */
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#define portWORD_SIZE (__riscv_xlen / 8)
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/* Number of FPU register */
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/* FPU is not yet supported so PORT_FPU_REGISTER = 0 */
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#define portasmFPU_CONTEXT_SIZE 0
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#include "freertos_risc_v_chip_specific_extensions.h"
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#include "freertos_risc_v_chip_specific_extensions.h"
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@ -85,20 +103,45 @@ definitions. */
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#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
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#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
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#endif
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#endif
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#ifndef portasmHANDLE_INTERRUPT
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#ifndef portHANDLE_INTERRUPT
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#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
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#error portHANDLE_INTERRUPT must be defined to the function to be called to handle external/peripheral interrupts.
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#endif
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#endif
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#ifndef portHANDLE_EXCEPTION
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#error portHANDLE_EXCEPTION must be defined to the function to be called to handle execptions.
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#endif
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#ifndef portasmHAS_SIFIVE_CLINT
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#ifndef portasmHAS_SIFIVE_CLINT
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#define portasmHAS_SIFIVE_CLINT 0
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#define portasmHAS_SIFIVE_CLINT 0
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#endif
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#endif
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/* Only the standard core registers are stored by default. Any additional
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/*
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registers must be saved by the portasmSAVE_ADDITIONAL_REGISTERS and
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* To maintain RISCV ABI stack alignment requirements (16bytes)
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portasmRESTORE_ADDITIONAL_REGISTERS macros - which can be defined in a chip
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* this data structure must be a MULTIPLE of 16 bytes in size.
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specific version of freertos_risc_v_chip_specific_extensions.h. See the notes
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* 32 Registers (for standard core) is 16byte aligned :)
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at the top of this file. */
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* We add space to save additional information so it must be multiple of 4.
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#define portCONTEXT_SIZE ( 30 * portWORD_SIZE )
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* mepc 33th register
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* mstatus 34th register
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* ruf 35th register
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* ruf 36th register
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*/
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#define PORT_CONTEXT_mepcIDX (portasmNB_REGS_SAVED)
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#define PORT_CONTEXT_mstatusIDX (portasmNB_REGS_SAVED + 1)
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#define portasmLAST_BASE_REGS (portasmNB_REGS_SAVED + 4)
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#define PORT_CONTEXT_lastIDX ((portasmNB_REGS_SAVED) + portasmADDITIONAL_CONTEXT_SIZE)
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/* used in assembler, as byte offsets from the start of the context */
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#define PORT_CONTEXT_xIDX(X) (X) /* index into "raw" for register x? */
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#define PORT_CONTEXT_xOFFSET(X) (PORT_CONTEXT_xIDX(X) * portWORD_SIZE)
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#define PORT_CONTEXT_mepcOFFSET (PORT_CONTEXT_mepcIDX * portWORD_SIZE)
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#define PORT_CONTEXT_mstatusOFFSET (PORT_CONTEXT_mstatusIDX * portWORD_SIZE)
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#define PORT_CONTEXT_rufOFFSET (PORT_CONTEXT_rufIDX * portWORD_SIZE)
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/* total size of the structure usable in ASM. */
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#define portasmREGISTER_CONTEXT_WORDSIZE ((portasmLAST_BASE_REGS) * (portWORD_SIZE))
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#define portasmADDITIONAL_CONTEXT_WORDSIZE ((portasmADDITIONAL_CONTEXT_SIZE) * (portWORD_SIZE))
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.global xPortStartFirstTask
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.global xPortStartFirstTask
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.global freertos_risc_v_trap_handler
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.global freertos_risc_v_trap_handler
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@ -112,184 +155,289 @@ at the top of this file. */
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.extern pullNextTime
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.extern pullNextTime
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.extern uxTimerIncrementsForOneTick /* size_t type so 32-bit on 32-bit core and 64-bits on 64-bit core. */
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.extern uxTimerIncrementsForOneTick /* size_t type so 32-bit on 32-bit core and 64-bits on 64-bit core. */
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.extern xISRStackTop
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.extern xISRStackTop
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.extern portasmHANDLE_INTERRUPT
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.extern portHANDLE_INTERRUPT
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.extern portHANDLE_EXCEPTION
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/*-----------------------------------------------------------*/
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.macro portSAVE_BaseReg
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/* Make room for the registers. */
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addi sp, sp, -portasmREGISTER_CONTEXT_WORDSIZE
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store_x x1, PORT_CONTEXT_xOFFSET(1)(sp) /* x1(ra) Return address */
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/* x2(sp) ***** Should be save ouside this macro */
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store_x x3, PORT_CONTEXT_xOFFSET(3)(sp) /* x3(gp) Global pointer */
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store_x x4, PORT_CONTEXT_xOFFSET(4)(sp) /* x4(tp) Thread pointer */
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store_x x5, PORT_CONTEXT_xOFFSET(5)(sp) /* x5(t0) Temporary register */
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store_x x6, PORT_CONTEXT_xOFFSET(6)(sp) /* x6(t1) Temporary register*/
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store_x x7, PORT_CONTEXT_xOFFSET(7)(sp) /* x7(t2) Temporary register */
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store_x x8, PORT_CONTEXT_xOFFSET(8)(sp) /* x8(s0/fp) Saved register/Frame pointer */
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store_x x9, PORT_CONTEXT_xOFFSET(9)(sp) /* x9(s1) Saved register */
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store_x x10, PORT_CONTEXT_xOFFSET(10)(sp) /* x10(a0) Function argument */
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store_x x11, PORT_CONTEXT_xOFFSET(11)(sp) /* x11(a1) Function argument */
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store_x x12, PORT_CONTEXT_xOFFSET(12)(sp) /* x12(a2) Function argument */
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store_x x13, PORT_CONTEXT_xOFFSET(13)(sp) /* x13(a3) Function argument */
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store_x x14, PORT_CONTEXT_xOFFSET(14)(sp) /* x14(a4) Function argument */
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store_x x15, PORT_CONTEXT_xOFFSET(15)(sp) /* x15(a5) Function argument */
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#ifndef __riscv_32e
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store_x x16, PORT_CONTEXT_xOFFSET(16)(sp) /* x16(a6) Function arguments */
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store_x x17, PORT_CONTEXT_xOFFSET(17)(sp) /* x17(a7) Function arguments */
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store_x x18, PORT_CONTEXT_xOFFSET(18)(sp) /* x18(s2) Saved register */
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store_x x19, PORT_CONTEXT_xOFFSET(19)(sp) /* x19(s3) Saved register */
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store_x x20, PORT_CONTEXT_xOFFSET(20)(sp) /* x20(s4) Saved register */
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store_x x21, PORT_CONTEXT_xOFFSET(21)(sp) /* x21(s5) Saved register */
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store_x x22, PORT_CONTEXT_xOFFSET(22)(sp) /* x22(s6) Saved register */
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store_x x23, PORT_CONTEXT_xOFFSET(23)(sp) /* x23(s7) Saved register */
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store_x x24, PORT_CONTEXT_xOFFSET(24)(sp) /* x24(s8) Saved register */
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store_x x25, PORT_CONTEXT_xOFFSET(25)(sp) /* x25(s9) Saved register */
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store_x x26, PORT_CONTEXT_xOFFSET(26)(sp) /* x26(s10) Saved register */
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store_x x27, PORT_CONTEXT_xOFFSET(27)(sp) /* x27(s11) Saved register */
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store_x x28, PORT_CONTEXT_xOFFSET(28)(sp) /* x28(t3) Temporary register */
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store_x x29, PORT_CONTEXT_xOFFSET(29)(sp) /* x29(t4) Temporary register */
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store_x x30, PORT_CONTEXT_xOFFSET(30)(sp) /* x30(t5) Temporary register */
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store_x x31, PORT_CONTEXT_xOFFSET(31)(sp) /* x31(t6) Temporary register */
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#endif /* __riscv_32e */
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/* Save mcause, mepc & mstatus state */
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csrr a4, mepc
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csrr a5, mstatus /* Required for MPIE bit. */
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store_x a4, PORT_CONTEXT_mepcOFFSET(sp)
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store_x a5, PORT_CONTEXT_mstatusOFFSET(sp)
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.endm
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/*-----------------------------------------------------------*/
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.macro portRESTORE_BaseReg
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/* Restore mepc & mstatus state */
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load_x t0, PORT_CONTEXT_mepcOFFSET(sp)
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load_x t1, PORT_CONTEXT_mstatusOFFSET(sp)
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csrw mepc, t0
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csrw mstatus, t1
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load_x x1, PORT_CONTEXT_xOFFSET(1)(sp) /* x1(ra) Return address */
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/* x2(sp) ***** Should be save ouside this macro */
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load_x x3, PORT_CONTEXT_xOFFSET(3)(sp) /* x3(gp) Global pointer */
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load_x x4, PORT_CONTEXT_xOFFSET(4)(sp) /* x4(tp) Thread pointer */
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load_x x5, PORT_CONTEXT_xOFFSET(5)(sp) /* x5(t0) Temporary register */
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load_x x6, PORT_CONTEXT_xOFFSET(6)(sp) /* x6(t1) Temporary register*/
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load_x x7, PORT_CONTEXT_xOFFSET(7)(sp) /* x7(t2) Temporary register */
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load_x x8, PORT_CONTEXT_xOFFSET(8)(sp) /* x8(s0/fp) Saved register/Frame pointer */
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load_x x9, PORT_CONTEXT_xOFFSET(9)(sp) /* x9(s1) Saved register */
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load_x x10, PORT_CONTEXT_xOFFSET(10)(sp) /* x10(a0) Function argument */
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load_x x11, PORT_CONTEXT_xOFFSET(11)(sp) /* x11(a1) Function argument */
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load_x x12, PORT_CONTEXT_xOFFSET(12)(sp) /* x12(a2) Function argument */
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load_x x13, PORT_CONTEXT_xOFFSET(13)(sp) /* x13(a3) Function argument */
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load_x x14, PORT_CONTEXT_xOFFSET(14)(sp) /* x14(a4) Function argument */
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load_x x15, PORT_CONTEXT_xOFFSET(15)(sp) /* x15(a5) Function argument */
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#ifndef __riscv_32e
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load_x x16, PORT_CONTEXT_xOFFSET(16)(sp) /* x16(a6) Function arguments */
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load_x x17, PORT_CONTEXT_xOFFSET(17)(sp) /* x17(a7) Function arguments */
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load_x x18, PORT_CONTEXT_xOFFSET(18)(sp) /* x18(s2) Saved register */
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load_x x19, PORT_CONTEXT_xOFFSET(19)(sp) /* x19(s3) Saved register */
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load_x x20, PORT_CONTEXT_xOFFSET(20)(sp) /* x20(s4) Saved register */
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load_x x21, PORT_CONTEXT_xOFFSET(21)(sp) /* x21(s5) Saved register */
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load_x x22, PORT_CONTEXT_xOFFSET(22)(sp) /* x22(s6) Saved register */
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load_x x23, PORT_CONTEXT_xOFFSET(23)(sp) /* x23(s7) Saved register */
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load_x x24, PORT_CONTEXT_xOFFSET(24)(sp) /* x24(s8) Saved register */
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load_x x25, PORT_CONTEXT_xOFFSET(25)(sp) /* x25(s9) Saved register */
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load_x x26, PORT_CONTEXT_xOFFSET(26)(sp) /* x26(s10) Saved register */
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load_x x27, PORT_CONTEXT_xOFFSET(27)(sp) /* x27(s11) Saved register */
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load_x x28, PORT_CONTEXT_xOFFSET(28)(sp) /* x28(t3) Temporary register */
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load_x x29, PORT_CONTEXT_xOFFSET(29)(sp) /* x29(t4) Temporary register */
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load_x x30, PORT_CONTEXT_xOFFSET(30)(sp) /* x30(t5) Temporary register */
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load_x x31, PORT_CONTEXT_xOFFSET(31)(sp) /* x31(t6) Temporary register */
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#endif /* __riscv_32e */
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.endm
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/*-----------------------------------------------------------*/
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/*-----------------------------------------------------------*/
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.align 8
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.align 8
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.func
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.func
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freertos_risc_v_trap_handler:
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freertos_risc_v_trap_handler:
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addi sp, sp, -portCONTEXT_SIZE
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/* We do not know if this is an ASYNC or SYNC
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store_x x1, 1 * portWORD_SIZE( sp )
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* If ASYNC, it is a normal interrupt
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store_x x5, 2 * portWORD_SIZE( sp )
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* and the stack pointer is assumed good.
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store_x x6, 3 * portWORD_SIZE( sp )
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* else (SYNC)
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store_x x7, 4 * portWORD_SIZE( sp )
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* We could be here due to a bus fault.
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store_x x8, 5 * portWORD_SIZE( sp )
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*/
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store_x x9, 6 * portWORD_SIZE( sp )
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csrw mscratch, t0
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store_x x10, 7 * portWORD_SIZE( sp )
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csrr t0, mcause
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store_x x11, 8 * portWORD_SIZE( sp )
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blt t0, x0, handle_interrupt
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store_x x12, 9 * portWORD_SIZE( sp )
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store_x x13, 10 * portWORD_SIZE( sp )
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store_x x14, 11 * portWORD_SIZE( sp )
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store_x x15, 12 * portWORD_SIZE( sp )
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store_x x16, 13 * portWORD_SIZE( sp )
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store_x x17, 14 * portWORD_SIZE( sp )
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store_x x18, 15 * portWORD_SIZE( sp )
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store_x x19, 16 * portWORD_SIZE( sp )
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store_x x20, 17 * portWORD_SIZE( sp )
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store_x x21, 18 * portWORD_SIZE( sp )
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store_x x22, 19 * portWORD_SIZE( sp )
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store_x x23, 20 * portWORD_SIZE( sp )
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store_x x24, 21 * portWORD_SIZE( sp )
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store_x x25, 22 * portWORD_SIZE( sp )
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store_x x26, 23 * portWORD_SIZE( sp )
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store_x x27, 24 * portWORD_SIZE( sp )
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store_x x28, 25 * portWORD_SIZE( sp )
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store_x x29, 26 * portWORD_SIZE( sp )
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store_x x30, 27 * portWORD_SIZE( sp )
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store_x x31, 28 * portWORD_SIZE( sp )
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csrr t0, mstatus /* Required for MPIE bit. */
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handle_exception:
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store_x t0, 29 * portWORD_SIZE( sp )
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/* mscratch = old t0
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* t0 = mcause
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* mcause = small number 0..16
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* 0 Instruction address misaligned
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* 1 Instruction access fault
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* 2 Illegal instruction
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* 3 Breakpoint
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* 4 Load address misaligned
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* 5 Load access fault
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* 6 Store/AMO address misaligned
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* 7 Store/AMO access fault
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* 8 Environment call from U-mode
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* 9 Environment call from S-mode
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* 10 Reserved
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* 11 Environment call from M-mode
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* 12 Instruction page fault
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* 13 Load page fault
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* 14 Reserved
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* 15 Store/AMO page fault
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* ≥16 Reserved
|
||||||
|
*
|
||||||
|
* if( mcause between 8 and 11 ) we are good - ecall
|
||||||
|
* else: problem
|
||||||
|
*/
|
||||||
|
|
||||||
portasmSAVE_ADDITIONAL_REGISTERS /* Defined in freertos_risc_v_chip_specific_extensions.h to save any registers unique to the RISC-V implementation. */
|
addi t0, t0, -8
|
||||||
|
blt t0, x0, is_exception /* mcause < 8, must be fault */
|
||||||
load_x t0, pxCurrentTCB /* Load pxCurrentTCB. */
|
addi t0, t0, -4
|
||||||
store_x sp, 0( t0 ) /* Write sp to first TCB member. */
|
blt t0, x0, ecall_yield
|
||||||
|
|
||||||
csrr a0, mcause
|
|
||||||
csrr a1, mepc
|
|
||||||
|
|
||||||
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. */
|
|
||||||
|
|
||||||
handle_asynchronous:
|
|
||||||
|
|
||||||
#if( portasmHAS_MTIME != 0 )
|
|
||||||
|
|
||||||
test_if_mtimer: /* If there is a CLINT then the mtimer is used to generate the tick interrupt. */
|
|
||||||
|
|
||||||
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. */
|
|
||||||
bne a0, t1, test_if_external_interrupt
|
|
||||||
|
|
||||||
load_x t0, pullMachineTimerCompareRegister /* Load address of compare register into t0. */
|
|
||||||
load_x t1, pullNextTime /* Load the address of ullNextTime into t1. */
|
|
||||||
|
|
||||||
#if( __riscv_xlen == 32 )
|
|
||||||
|
|
||||||
/* 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. */
|
|
||||||
|
|
||||||
#endif /* __riscv_xlen == 32 */
|
|
||||||
|
|
||||||
#if( __riscv_xlen == 64 )
|
|
||||||
|
|
||||||
/* 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. */
|
|
||||||
|
|
||||||
#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:
|
is_exception:
|
||||||
csrr t0, mcause /* For viewing in the debugger only. */
|
/* restore t0 and save sp in mscratch. */
|
||||||
csrr t1, mepc /* For viewing in the debugger only */
|
csrr t0, mscratch
|
||||||
csrr t2, mstatus
|
csrw mscratch, sp
|
||||||
j is_exception /* No other exceptions handled yet. */
|
/* 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
|
||||||
|
/* Execption is treated by external function */
|
||||||
|
jal portHANDLE_EXCEPTION
|
||||||
|
/* in case that the go back from exception, restore registers */
|
||||||
|
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)
|
||||||
|
|
||||||
as_yet_unhandled:
|
/* Defined in freertos_risc_v_chip_specific_extensions.h to save any registers unique to the RISC-V implementation. */
|
||||||
csrr t0, mcause /* For viewing in the debugger only. */
|
portasmSAVE_ADDITIONAL_REGISTERS
|
||||||
j as_yet_unhandled
|
|
||||||
|
|
||||||
processed_source:
|
/* Load pxCurrentTCB and update first TCB member(pxTopOfStack) with sp. */
|
||||||
load_x t1, pxCurrentTCB /* Load pxCurrentTCB. */
|
load_x s0, pxCurrentTCB
|
||||||
load_x sp, 0( t1 ) /* Read sp from first TCB member. */
|
store_x sp, 0( s0 )
|
||||||
|
|
||||||
/* Load mret with the address of the next instruction in the task to run next. */
|
/* Save sp into s1 */
|
||||||
load_x t0, 0( sp )
|
mv s1, sp
|
||||||
csrw mepc, t0
|
load_x sp, xISRStackTop /* Switch to ISR stack before function call. */
|
||||||
|
|
||||||
portasmRESTORE_ADDITIONAL_REGISTERS /* Defined in freertos_risc_v_chip_specific_extensions.h to restore any registers unique to the RISC-V implementation. */
|
j switch_context
|
||||||
|
|
||||||
/* Load mstatus with the interrupt enable bits used by the task. */
|
handle_interrupt:
|
||||||
load_x t0, 29 * portWORD_SIZE( sp )
|
portSAVE_BaseReg
|
||||||
csrw mstatus, t0 /* Required for MPIE bit. */
|
/* a4 = mepc
|
||||||
|
* a5 = mstatus
|
||||||
|
* s0 will be use for pxCurrentTCB
|
||||||
|
* s1 will be use to save sp
|
||||||
|
*/
|
||||||
|
|
||||||
load_x x1, 1 * portWORD_SIZE( sp )
|
/* Store the value of sp when the interrupt occur */
|
||||||
load_x x5, 2 * portWORD_SIZE( sp ) /* t0 */
|
addi t0, sp, portasmREGISTER_CONTEXT_WORDSIZE
|
||||||
load_x x6, 3 * portWORD_SIZE( sp ) /* t1 */
|
store_x t0, PORT_CONTEXT_xOFFSET(2)(sp)
|
||||||
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
|
|
||||||
|
|
||||||
|
/* Defined in freertos_risc_v_chip_specific_extensions.h to save any registers unique to the RISC-V implementation. */
|
||||||
|
portasmSAVE_ADDITIONAL_REGISTERS
|
||||||
|
|
||||||
|
/* 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. */
|
||||||
|
|
||||||
|
#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
|
||||||
|
|
||||||
|
load_x t0, pullMachineTimerCompareRegister /* Load address of compare register into t0. */
|
||||||
|
load_x t1, pullNextTime /* Load the address of ullNextTime into t1. */
|
||||||
|
|
||||||
|
#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 ) */
|
||||||
|
|
||||||
|
jal xTaskIncrementTick
|
||||||
|
beqz a0, restore_before_exit /* Don't switch context if incrementing tick didn't unblock a task. */
|
||||||
|
j switch_context
|
||||||
|
|
||||||
|
restore_before_exit:
|
||||||
|
mv sp, s1
|
||||||
|
j end_trap_handler
|
||||||
|
|
||||||
|
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 ) */
|
||||||
|
|
||||||
|
external_interrupt:
|
||||||
|
/* Switch to ISR stack before function call. */
|
||||||
|
load_x sp, xISRStackTop
|
||||||
|
jal portHANDLE_INTERRUPT
|
||||||
|
mv sp, s1
|
||||||
|
j end_trap_handler
|
||||||
|
|
||||||
|
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
|
||||||
|
|
||||||
|
switch_context:
|
||||||
|
jal vTaskSwitchContext
|
||||||
|
load_x s0, pxCurrentTCB /* Load pxCurrentTCB. */
|
||||||
|
load_x sp, 0( s0 ) /* Read sp from first TCB member. */
|
||||||
|
|
||||||
|
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. */
|
||||||
|
|
||||||
|
/* restore registers */
|
||||||
|
portasmRESTORE_ADDITIONAL_REGISTERS
|
||||||
|
portRESTORE_BaseReg
|
||||||
|
load_x x2, PORT_CONTEXT_xOFFSET(2)(sp)
|
||||||
mret
|
mret
|
||||||
.endfunc
|
.endfunc
|
||||||
/*-----------------------------------------------------------*/
|
/*-----------------------------------------------------------*/
|
||||||
|
|
@ -304,49 +452,31 @@ xPortStartFirstTask:
|
||||||
outside of this file. */
|
outside of this file. */
|
||||||
la t0, freertos_risc_v_trap_handler
|
la t0, freertos_risc_v_trap_handler
|
||||||
csrw mtvec, t0
|
csrw mtvec, t0
|
||||||
#endif /* portasmHAS_CLILNT */
|
#endif /* ( portasmHAS_SIFIVE_CLINT != 0 ) */
|
||||||
|
|
||||||
load_x sp, pxCurrentTCB /* Load pxCurrentTCB. */
|
/** Set all register to the FirstTask context */
|
||||||
load_x sp, 0( sp ) /* Read sp from first TCB member. */
|
load_x t2, pxCurrentTCB /* Load pxCurrentTCB. */
|
||||||
|
load_x sp, 0( t2 ) /* Read sp from first TCB member. */
|
||||||
|
|
||||||
load_x x1, 0( sp ) /* Note for starting the scheduler the exception return address is used as the function return address. */
|
/* 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. */
|
||||||
|
|
||||||
portasmRESTORE_ADDITIONAL_REGISTERS /* Defined in freertos_risc_v_chip_specific_extensions.h to restore any registers unique to the RISC-V implementation. */
|
/* enable interrupt */
|
||||||
|
#if( portasmHAS_MTIME != 0 )
|
||||||
|
li t0, 0x880
|
||||||
|
csrs mie, t0
|
||||||
|
#else
|
||||||
|
li t0, 0x800
|
||||||
|
csrs mie, t0
|
||||||
|
#endif /* ( portasmHAS_MTIME != 0 ) */
|
||||||
|
|
||||||
load_x x6, 3 * portWORD_SIZE( sp ) /* t1 */
|
portasmRESTORE_ADDITIONAL_REGISTERS
|
||||||
load_x x7, 4 * portWORD_SIZE( sp ) /* t2 */
|
portRESTORE_BaseReg
|
||||||
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 */
|
|
||||||
|
|
||||||
load_x x5, 29 * portWORD_SIZE( sp ) /* Initial mstatus into x5 (t0) */
|
load_x ra, PORT_CONTEXT_mepcOFFSET(sp) /* Note for starting the scheduler the exception return address is used as the function return address. */
|
||||||
addi x5, x5, 0x08 /* Set MIE bit so the first task starts with interrupts enabled - required as returns with ret not eret. */
|
load_x x2, PORT_CONTEXT_xOFFSET(2)(sp)
|
||||||
csrrw x0, mstatus, x5 /* Interrupts enabled from here! */
|
mret
|
||||||
load_x x5, 2 * portWORD_SIZE( sp ) /* Initial x5 (t0) value. */
|
|
||||||
|
|
||||||
addi sp, sp, portCONTEXT_SIZE
|
|
||||||
ret
|
|
||||||
.endfunc
|
.endfunc
|
||||||
/*-----------------------------------------------------------*/
|
/*-----------------------------------------------------------*/
|
||||||
|
|
||||||
|
|
@ -360,7 +490,7 @@ xPortStartFirstTask:
|
||||||
* a1, and pvParameters in a2. The new top of stack is passed out in a0.
|
* 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
|
* 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, currently I assumed).
|
* for the 'I' profile, X1 to X15 for the 'E' profile).
|
||||||
*
|
*
|
||||||
* Register ABI Name Description Saver
|
* Register ABI Name Description Saver
|
||||||
* x0 zero Hard-wired zero -
|
* x0 zero Hard-wired zero -
|
||||||
|
|
@ -379,36 +509,44 @@ xPortStartFirstTask:
|
||||||
* The RISC-V context is saved t FreeRTOS tasks in the following stack frame,
|
* 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
|
* where the global and thread pointers are currently assumed to be constant so
|
||||||
* are not saved:
|
* 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
|
* mstatus
|
||||||
* x31
|
* x31 (Only for 'I' profile)
|
||||||
* x30
|
* x30 (Only for 'I' profile)
|
||||||
* x29
|
* x29 (Only for 'I' profile)
|
||||||
* x28
|
* x28 (Only for 'I' profile)
|
||||||
* x27
|
* x27 (Only for 'I' profile)
|
||||||
* x26
|
* x26 (Only for 'I' profile)
|
||||||
* x25
|
* x25 (Only for 'I' profile)
|
||||||
* x24
|
* x24 (Only for 'I' profile)
|
||||||
* x23
|
* x23 (Only for 'I' profile)
|
||||||
* x22
|
* x22 (Only for 'I' profile)
|
||||||
* x21
|
* x21 (Only for 'I' profile)
|
||||||
* x20
|
* x20 (Only for 'I' profile)
|
||||||
* x19
|
* x19 (Only for 'I' profile)
|
||||||
* x18
|
* x18 (Only for 'I' profile)
|
||||||
* x17
|
* x17 (Only for 'I' profile)
|
||||||
* x16
|
* x16 (Only for 'I' profile)
|
||||||
* x15
|
* x15
|
||||||
* x14
|
* x14
|
||||||
* x13
|
* x13
|
||||||
* x12
|
* x12
|
||||||
* x11
|
* x11
|
||||||
* pvParameters
|
* pvParameters - x10 (a0)
|
||||||
* x9
|
* x9
|
||||||
* x8
|
* x8
|
||||||
* x7
|
* x7
|
||||||
* x6
|
* x6
|
||||||
* x5
|
* x5
|
||||||
* portTASK_RETURN_ADDRESS
|
* x4 (tp)
|
||||||
|
* x3 (gp)
|
||||||
|
* x2 (sp)
|
||||||
|
* portTASK_RETURN_ADDRESS - x1 (ra)
|
||||||
|
* x0
|
||||||
* [chip specific registers go here]
|
* [chip specific registers go here]
|
||||||
* pxCode
|
* pxCode
|
||||||
*/
|
*/
|
||||||
|
|
@ -416,28 +554,80 @@ xPortStartFirstTask:
|
||||||
.func
|
.func
|
||||||
pxPortInitialiseStack:
|
pxPortInitialiseStack:
|
||||||
|
|
||||||
csrr t0, mstatus /* Obtain current mstatus value. */
|
/* Obtain current mstatus value. */
|
||||||
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. */
|
csrr t0, mstatus
|
||||||
addi t1, x0, 0x188 /* Generate the value 0x1880, which are the MPIE and MPP bits to set in mstatus. */
|
/* Generate the value 0x1880, which are the MPIE and MPP bits to set in mstatus. */
|
||||||
|
addi t1, x0, 0x188
|
||||||
slli t1, t1, 4
|
slli t1, t1, 4
|
||||||
or t0, t0, t1 /* Set MPIE and MPP bits in mstatus value. */
|
/* reset previous value */
|
||||||
|
not t2, t1
|
||||||
|
and t0, t0, t2
|
||||||
|
/* Generate the value 0x1880, which are the MPIE and MPP bits to set in mstatus. */
|
||||||
|
addi t1, x0, 0x188
|
||||||
|
slli t1, t1, 4
|
||||||
|
/* Set MPIE and MPP bits in mstatus value. */
|
||||||
|
or t0, t0, t1
|
||||||
|
|
||||||
addi a0, a0, -portWORD_SIZE
|
/* Make room for the registers. */
|
||||||
store_x t0, 0(a0) /* mstatus onto the stack. */
|
addi t2, a0, -portasmREGISTER_CONTEXT_WORDSIZE
|
||||||
addi a0, a0, -(22 * portWORD_SIZE) /* Space for registers x11-x31. */
|
/* x1(ra) Return address */
|
||||||
store_x a2, 0(a0) /* Task parameters (pvParameters parameter) goes into register X10/a0 on the stack. */
|
store_x x0, PORT_CONTEXT_xOFFSET(1)(t2)
|
||||||
addi a0, a0, -(6 * portWORD_SIZE) /* Space for registers x5-x9. */
|
/* x2(sp) ***** Should be save ouside this macro */
|
||||||
store_x x0, 0(a0) /* Return address onto the stack, could be portTASK_RETURN_ADDRESS */
|
store_x a0, PORT_CONTEXT_xOFFSET(2)(t2)
|
||||||
addi t0, x0, portasmADDITIONAL_CONTEXT_SIZE /* The number of chip specific additional registers. */
|
/* x3(gp) Global pointer */
|
||||||
|
store_x x3, PORT_CONTEXT_xOFFSET(3)(t2)
|
||||||
|
/* x4(tp) Thread pointer */
|
||||||
|
store_x x4, PORT_CONTEXT_xOFFSET(4)(t2)
|
||||||
|
/* x5-7(t0-2) Temporaries */
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(5)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(6)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(7)(t2)
|
||||||
|
/* x8(s0/fp) Saved register/Frame pointer */
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(8)(t2)
|
||||||
|
/* x9(s1) Saved register */
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(9)(t2)
|
||||||
|
/* x10-17(a0-7) Function arguments */
|
||||||
|
store_x a2, PORT_CONTEXT_xOFFSET(10)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(11)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(12)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(13)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(14)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(15)(t2)
|
||||||
|
#ifndef __riscv_32e
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(16)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(17)(t2)
|
||||||
|
/* x18-27(s2-11) Saved registers */
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(18)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(19)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(20)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(21)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(22)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(23)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(24)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(25)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(26)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(27)(t2)
|
||||||
|
/* x28-31(t3-6) Temporaries */
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(28)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(29)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(30)(t2)
|
||||||
|
store_x x0, PORT_CONTEXT_xOFFSET(31)(t2)
|
||||||
|
#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
|
||||||
chip_specific_stack_frame: /* First add any chip specific registers to the stack frame being created. */
|
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. */
|
beq t0, x0, 1f /* No more chip specific registers to save. */
|
||||||
addi a0, a0, -portWORD_SIZE /* Make space for chip specific register. */
|
addi t2, t2, -portWORD_SIZE /* Make space for chip specific register. */
|
||||||
store_x x0, 0(a0) /* Give the chip specific register an initial value of zero. */
|
store_x x0, 0(t2) /* Give the chip specific register an initial value of zero. */
|
||||||
addi t0, t0, -1 /* Decrement the count of chip specific registers remaining. */
|
addi t0, t0, -1 /* Decrement the count of chip specific registers remaining. */
|
||||||
j chip_specific_stack_frame /* Until no more chip specific registers. */
|
j chip_specific_stack_frame /* Until no more chip specific registers. */
|
||||||
1:
|
1:
|
||||||
addi a0, a0, -portWORD_SIZE
|
|
||||||
store_x a1, 0(a0) /* mret value (pxCode parameter) onto the stack. */
|
mv a0, t2
|
||||||
ret
|
ret
|
||||||
.endfunc
|
.endfunc
|
||||||
/*-----------------------------------------------------------*/
|
/*-----------------------------------------------------------*/
|
||||||
|
|
|
||||||
Loading…
Add table
Add a link
Reference in a new issue