nuclei-sdk/OS/ThreadX/ports/nuclei/iar/interrupt.S

#include "riscv_encoding.h"

DISABLE_MIE MACRO
  csrci CSR_MSTATUS, MSTATUS_MIE
  ENDM

SAVE_CONTEXT MACRO
#if defined(ECLIC_HW_CTX_AUTO) && defined(CFG_HAS_ECLICV2)
#else
    csrrw sp, CSR_MSCRATCHCSWL, sp
    /* Allocate stack space for context saving */
#ifndef __riscv_32e
    addi sp, sp, -20*REGBYTES
#else
    addi sp, sp, -14*REGBYTES
#endif /* __riscv_32e */

    STORE x1, 0*REGBYTES(sp)
    STORE x4, 1*REGBYTES(sp)
    STORE x5, 2*REGBYTES(sp)
    STORE x6, 3*REGBYTES(sp)
    STORE x7, 4*REGBYTES(sp)
    STORE x10, 5*REGBYTES(sp)
    STORE x11, 6*REGBYTES(sp)
    STORE x12, 7*REGBYTES(sp)
    STORE x13, 8*REGBYTES(sp)
    STORE x14, 9*REGBYTES(sp)
    STORE x15, 10*REGBYTES(sp)
#ifndef __riscv_32e
    STORE x16, 14*REGBYTES(sp)
    STORE x17, 15*REGBYTES(sp)
    STORE x28, 16*REGBYTES(sp)
    STORE x29, 17*REGBYTES(sp)
    STORE x30, 18*REGBYTES(sp)
    STORE x31, 19*REGBYTES(sp)
#endif /* __riscv_32e */
#endif
  ENDM

RESTORE_CONTEXT MACRO
#if defined(ECLIC_HW_CTX_AUTO) && defined(CFG_HAS_ECLICV2)
#else
    LOAD x1, 0*REGBYTES(sp)
    LOAD x4, 1*REGBYTES(sp)
    LOAD x5, 2*REGBYTES(sp)
    LOAD x6, 3*REGBYTES(sp)
    LOAD x7, 4*REGBYTES(sp)
    LOAD x10, 5*REGBYTES(sp)
    LOAD x11, 6*REGBYTES(sp)
    LOAD x12, 7*REGBYTES(sp)
    LOAD x13, 8*REGBYTES(sp)
    LOAD x14, 9*REGBYTES(sp)
    LOAD x15, 10*REGBYTES(sp)
#ifndef __riscv_32e
    LOAD x16, 14*REGBYTES(sp)
    LOAD x17, 15*REGBYTES(sp)
    LOAD x28, 16*REGBYTES(sp)
    LOAD x29, 17*REGBYTES(sp)
    LOAD x30, 18*REGBYTES(sp)
    LOAD x31, 19*REGBYTES(sp)

    /* De-allocate the stack space */
    addi sp, sp, 20*REGBYTES
#else
    /* De-allocate the stack space */
    addi sp, sp, 14*REGBYTES
#endif /* __riscv_32e */
    csrrw sp, CSR_MSCRATCHCSWL, sp
#endif
  ENDM

SAVE_CSR_CONTEXT MACRO
#if defined(ECLIC_HW_CTX_AUTO) && defined(CFG_HAS_ECLICV2)
#else
    /* Store CSR mcause to stack using pushmcause */
    csrrwi  x0, CSR_PUSHMCAUSE, 11
    /* Store CSR mepc to stack using pushmepc */
    csrrwi  x0, CSR_PUSHMEPC, 12
    /* Store CSR msub to stack using pushmsub */
    csrrwi  x0, CSR_PUSHMSUBM, 13
#endif
  ENDM

RESTORE_CSR_CONTEXT MACRO
#if defined(ECLIC_HW_CTX_AUTO) && defined(CFG_HAS_ECLICV2)
#else
    LOAD x5,  13*REGBYTES(sp)
    csrw CSR_MSUBM, x5
    LOAD x5,  12*REGBYTES(sp)
    csrw CSR_MEPC, x5
    LOAD x5,  11*REGBYTES(sp)
    csrw CSR_MCAUSE, x5
#endif
  ENDM

    PUBLIC exc_entry, irq_entry, default_intexc_handler
    PUBLIC Undef_Handler
    EXTERN core_exception_handler
    SECTION `.text`:CODE:NOROOT(2)
    CODE

/**
 * \brief  Exception/NMI Entry
 * \details
 * This function provide common entry functions for exception/nmi.
 * \remarks
 * This function provide a default exception/nmi entry.
 * ABI defined caller save register and some CSR registers
 * to be saved before enter interrupt handler and be restored before return.
 */
/* In CLIC mode, the exeception entry must be 64bytes aligned */
    ALIGN 6
exc_entry:
    /* Save the caller saving registers (context) */
    SAVE_CONTEXT
    /* Save the necessary CSR registers */
    SAVE_CSR_CONTEXT

    /*
     * Set the exception handler function arguments
     * argument 1: mcause value
     * argument 2: current stack point(SP) value
     */
    csrr a0, mcause
    mv a1, sp
    /*
     * TODO: Call the exception handler function
     * By default, the function template is provided in
     * system_Device.c, you can adjust it as you want
     */
    call core_exception_handler

    /* Restore the necessary CSR registers */
    RESTORE_CSR_CONTEXT
    /* Restore the caller saving registers (context) */
    RESTORE_CONTEXT

    /* Return to regular code */
#if defined(ECLIC_HW_CTX_AUTO) && defined(CFG_HAS_ECLICV2)
    csrrwi x0, CSR_POPXRET, 0
#else
    mret
#endif

/**
 * \brief  Non-Vector Interrupt Entry
 * \details
 * This function provide common entry functions for handling
 * non-vector interrupts
 * \remarks
 * This function provide a default non-vector interrupt entry.
 * ABI defined caller save register and some CSR registers need
 * to be saved before enter interrupt handler and be restored before return.
 */
/* In CLIC mode, the interrupt entry must be 4bytes aligned */
    ALIGN 2
/* This label will be set to MTVT2 register */
irq_entry:
    /* Save the caller saving registers (context) */
    SAVE_CONTEXT
    /* Save the necessary CSR registers */
    SAVE_CSR_CONTEXT

    /* This special CSR read/write operation, which is actually
     * claim the CLIC to find its pending highest ID, if the ID
     * is not 0, then automatically enable the mstatus.MIE, and
     * jump to its vector-entry-label, and update the link register
     */
    csrrw ra, CSR_JALMNXTI, ra

    /* Critical section with interrupts disabled */
    DISABLE_MIE

    /* Restore the necessary CSR registers */
    RESTORE_CSR_CONTEXT
    /* Restore the caller saving registers (context) */
    RESTORE_CONTEXT

    /* Return to regular code */
#if defined(ECLIC_HW_CTX_AUTO) && defined(CFG_HAS_ECLICV2)
    csrrwi x0, CSR_POPXRET, 0
#else
    mret
#endif

/* Default Handler for Exceptions / Interrupts */
Undef_Handler:
default_intexc_handler:
    j Undef_Handler

    END