Resolve conflicts

6 files changed, 721 insertions, 1 deletions

diff --git a/libcpu/risc-v/SConscript b/libcpu/risc-v/SConscript
index 640e46a4fb..024cc5ba44 100644
--- a/libcpu/risc-v/SConscript
+++ b/libcpu/risc-v/SConscript
@@ -10,7 +10,8 @@ group = []
 list  = os.listdir(cwd)
 
 # add common code files
-group = group + SConscript(os.path.join('common', 'SConscript'))
+if rtconfig.CPU != "nuclei":
+    group = group + SConscript(os.path.join('common', 'SConscript'))
 
 # cpu porting code files
 group = group + SConscript(os.path.join(rtconfig.CPU, 'SConscript'))
diff --git a/libcpu/risc-v/nuclei/SConscript b/libcpu/risc-v/nuclei/SConscript
new file mode 100644
index 0000000000..b0ae20ba02
--- /dev/null
+++ b/libcpu/risc-v/nuclei/SConscript
@@ -0,0 +1,14 @@
+# RT-Thread building script for component
+
+from building import *
+
+Import('rtconfig')
+
+cwd     = GetCurrentDir()
+src     = Glob('*.c') + Glob('*.cpp') + Glob('*_gcc.S')
+CPPPATH = [cwd]
+ASFLAGS = ''
+
+group = DefineGroup('cpu', src, depend = [''], CPPPATH = CPPPATH, ASFLAGS = ASFLAGS)
+
+Return('group')
diff --git a/libcpu/risc-v/nuclei/context_gcc.S b/libcpu/risc-v/nuclei/context_gcc.S
new file mode 100644
index 0000000000..fda453940d
--- /dev/null
+++ b/libcpu/risc-v/nuclei/context_gcc.S
@@ -0,0 +1,188 @@
+/*
+ * Copyright (c) 2019-Present Nuclei Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2020/03/26     Huaqi        First Nuclei RISC-V porting implementation
+ */
+
+#include "riscv_encoding.h"
+
+#ifndef __riscv_32e
+#define RT_SAVED_REGNUM         30
+#else
+#define RT_SAVED_REGNUM         14
+#endif
+
+#define RT_CONTEXT_SIZE         (RT_SAVED_REGNUM * REGBYTES)
+
+    .extern rt_interrupt_from_thread
+    .extern rt_interrupt_to_thread
+
+
+.section    .text
+
+
+/*
+ * void rt_hw_context_switch_to(rt_ubase_t to);
+ * a0 --> to_thread
+ */
+    .globl rt_hw_context_switch_to
+
+/* Start the first task.  This also clears the bit that indicates the FPU is
+	in use in case the FPU was used before the scheduler was started - which
+	would otherwise result in the unnecessary leaving of space in the stack
+	for lazy saving of FPU registers. */
+.align 3
+rt_hw_context_switch_to:
+    /* Setup Interrupt Stack using
+       The stack that was used by main()
+       before the scheduler is started is
+       no longer required after the scheduler is started.
+       Interrupt stack pointer is stored in CSR_MSCRATCH */
+    la t0, _sp
+    csrw CSR_MSCRATCH, t0
+    LOAD sp, 0x0(a0)                /* Read sp from first TCB member(a0) */
+
+    /* Pop PC from stack and set MEPC */
+    LOAD t0,  0  * REGBYTES(sp)
+    csrw CSR_MEPC, t0
+    /* Pop mstatus from stack and set it */
+    LOAD t0,  (RT_SAVED_REGNUM - 1)  * REGBYTES(sp)
+    csrw CSR_MSTATUS, t0
+    /* Interrupt still disable here */
+    /* Restore Registers from Stack */
+    LOAD x1,  1  * REGBYTES(sp)    /* RA */
+    LOAD x5,  2  * REGBYTES(sp)
+    LOAD x6,  3  * REGBYTES(sp)
+    LOAD x7,  4  * REGBYTES(sp)
+    LOAD x8,  5  * REGBYTES(sp)
+    LOAD x9,  6  * REGBYTES(sp)
+    LOAD x10, 7  * REGBYTES(sp)
+    LOAD x11, 8  * REGBYTES(sp)
+    LOAD x12, 9  * REGBYTES(sp)
+    LOAD x13, 10 * REGBYTES(sp)
+    LOAD x14, 11 * REGBYTES(sp)
+    LOAD x15, 12 * REGBYTES(sp)
+#ifndef __riscv_32e
+    LOAD x16, 13 * REGBYTES(sp)
+    LOAD x17, 14 * REGBYTES(sp)
+    LOAD x18, 15 * REGBYTES(sp)
+    LOAD x19, 16 * REGBYTES(sp)
+    LOAD x20, 17 * REGBYTES(sp)
+    LOAD x21, 18 * REGBYTES(sp)
+    LOAD x22, 19 * REGBYTES(sp)
+    LOAD x23, 20 * REGBYTES(sp)
+    LOAD x24, 21 * REGBYTES(sp)
+    LOAD x25, 22 * REGBYTES(sp)
+    LOAD x26, 23 * REGBYTES(sp)
+    LOAD x27, 24 * REGBYTES(sp)
+    LOAD x28, 25 * REGBYTES(sp)
+    LOAD x29, 26 * REGBYTES(sp)
+    LOAD x30, 27 * REGBYTES(sp)
+    LOAD x31, 28 * REGBYTES(sp)
+#endif
+
+    addi sp, sp, RT_CONTEXT_SIZE
+
+    mret
+
+.align 2
+.global eclic_msip_handler
+eclic_msip_handler:
+    addi sp, sp, -RT_CONTEXT_SIZE
+    STORE x1,  1  * REGBYTES(sp)    /* RA */
+    STORE x5,  2  * REGBYTES(sp)
+    STORE x6,  3  * REGBYTES(sp)
+    STORE x7,  4  * REGBYTES(sp)
+    STORE x8,  5  * REGBYTES(sp)
+    STORE x9,  6  * REGBYTES(sp)
+    STORE x10, 7  * REGBYTES(sp)
+    STORE x11, 8  * REGBYTES(sp)
+    STORE x12, 9  * REGBYTES(sp)
+    STORE x13, 10 * REGBYTES(sp)
+    STORE x14, 11 * REGBYTES(sp)
+    STORE x15, 12 * REGBYTES(sp)
+#ifndef __riscv_32e
+    STORE x16, 13 * REGBYTES(sp)
+    STORE x17, 14 * REGBYTES(sp)
+    STORE x18, 15 * REGBYTES(sp)
+    STORE x19, 16 * REGBYTES(sp)
+    STORE x20, 17 * REGBYTES(sp)
+    STORE x21, 18 * REGBYTES(sp)
+    STORE x22, 19 * REGBYTES(sp)
+    STORE x23, 20 * REGBYTES(sp)
+    STORE x24, 21 * REGBYTES(sp)
+    STORE x25, 22 * REGBYTES(sp)
+    STORE x26, 23 * REGBYTES(sp)
+    STORE x27, 24 * REGBYTES(sp)
+    STORE x28, 25 * REGBYTES(sp)
+    STORE x29, 26 * REGBYTES(sp)
+    STORE x30, 27 * REGBYTES(sp)
+    STORE x31, 28 * REGBYTES(sp)
+#endif
+    /* Push mstatus to stack */
+    csrr t0, CSR_MSTATUS
+    STORE t0,  (RT_SAVED_REGNUM - 1)  * REGBYTES(sp)
+
+    /* Push additional registers */
+
+    /* Store sp to task stack */
+    LOAD t0, rt_interrupt_from_thread
+    STORE sp, 0(t0)
+
+    csrr t0, CSR_MEPC
+    STORE t0, 0(sp)
+
+    jal rt_hw_taskswitch
+
+    /* Switch task context */
+    LOAD t0, rt_interrupt_to_thread
+    LOAD sp, 0x0(t0)
+
+    /* Pop PC from stack and set MEPC */
+    LOAD t0,  0  * REGBYTES(sp)
+    csrw CSR_MEPC, t0
+
+    /* Pop additional registers */
+
+    /* Pop mstatus from stack and set it */
+    LOAD t0,  (RT_SAVED_REGNUM - 1)  * REGBYTES(sp)
+    csrw CSR_MSTATUS, t0
+    /* Interrupt still disable here */
+    /* Restore Registers from Stack */
+    LOAD x1,  1  * REGBYTES(sp)    /* RA */
+    LOAD x5,  2  * REGBYTES(sp)
+    LOAD x6,  3  * REGBYTES(sp)
+    LOAD x7,  4  * REGBYTES(sp)
+    LOAD x8,  5  * REGBYTES(sp)
+    LOAD x9,  6  * REGBYTES(sp)
+    LOAD x10, 7  * REGBYTES(sp)
+    LOAD x11, 8  * REGBYTES(sp)
+    LOAD x12, 9  * REGBYTES(sp)
+    LOAD x13, 10 * REGBYTES(sp)
+    LOAD x14, 11 * REGBYTES(sp)
+    LOAD x15, 12 * REGBYTES(sp)
+#ifndef __riscv_32e
+    LOAD x16, 13 * REGBYTES(sp)
+    LOAD x17, 14 * REGBYTES(sp)
+    LOAD x18, 15 * REGBYTES(sp)
+    LOAD x19, 16 * REGBYTES(sp)
+    LOAD x20, 17 * REGBYTES(sp)
+    LOAD x21, 18 * REGBYTES(sp)
+    LOAD x22, 19 * REGBYTES(sp)
+    LOAD x23, 20 * REGBYTES(sp)
+    LOAD x24, 21 * REGBYTES(sp)
+    LOAD x25, 22 * REGBYTES(sp)
+    LOAD x26, 23 * REGBYTES(sp)
+    LOAD x27, 24 * REGBYTES(sp)
+    LOAD x28, 25 * REGBYTES(sp)
+    LOAD x29, 26 * REGBYTES(sp)
+    LOAD x30, 27 * REGBYTES(sp)
+    LOAD x31, 28 * REGBYTES(sp)
+#endif
+
+    addi sp, sp, RT_CONTEXT_SIZE
+    mret
diff --git a/libcpu/risc-v/nuclei/cpuport.c b/libcpu/risc-v/nuclei/cpuport.c
new file mode 100644
index 0000000000..fad9afdf4c
--- /dev/null
+++ b/libcpu/risc-v/nuclei/cpuport.c
@@ -0,0 +1,259 @@
+/*
+ * Copyright (c) 2006-2018, RT-Thread Development Team
+ * Copyright (c) 2019-Present Nuclei Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2020/03/26     Huaqi        Nuclei RISC-V Core porting code.
+ */
+
+#include <rthw.h>
+#include <rtthread.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "cpuport.h"
+
+#define SYSTICK_TICK_CONST                      (SOC_TIMER_FREQ / RT_TICK_PER_SECOND)
+
+/* Interrupt level for kernel systimer interrupt and software timer interrupt */
+#define RT_KERNEL_INTERRUPT_LEVEL               1
+
+/* Initial CSR MSTATUS value when thread created */
+#define RT_INITIAL_MSTATUS                      (MSTATUS_MPP | MSTATUS_MPIE | MSTATUS_FS_INITIAL)
+
+/**
+ * @brief from thread used interrupt context switch
+ * 
+ */
+volatile rt_ubase_t  rt_interrupt_from_thread = 0;
+/**
+ * @brief to thread used interrupt context switch
+ * 
+ */
+volatile rt_ubase_t  rt_interrupt_to_thread   = 0;
+/**
+ * @brief flag to indicate context switch in interrupt or not
+ * 
+ */
+volatile rt_ubase_t rt_thread_switch_interrupt_flag = 0;
+
+/**
+ * @brief thread stack frame of saved context
+ * 
+ */
+struct rt_hw_stack_frame
+{
+    rt_ubase_t epc;        /*!< epc - epc    - program counter                     */
+    rt_ubase_t ra;         /*!< x1  - ra     - return address for jumps            */
+    rt_ubase_t t0;         /*!< x5  - t0     - temporary register 0                */
+    rt_ubase_t t1;         /*!< x6  - t1     - temporary register 1                */
+    rt_ubase_t t2;         /*!< x7  - t2     - temporary register 2                */
+    rt_ubase_t s0_fp;      /*!< x8  - s0/fp  - saved register 0 or frame pointer   */
+    rt_ubase_t s1;         /*!< x9  - s1     - saved register 1                    */
+    rt_ubase_t a0;         /*!< x10 - a0     - return value or function argument 0 */
+    rt_ubase_t a1;         /*!< x11 - a1     - return value or function argument 1 */
+    rt_ubase_t a2;         /*!< x12 - a2     - function argument 2                 */
+    rt_ubase_t a3;         /*!< x13 - a3     - function argument 3                 */
+    rt_ubase_t a4;         /*!< x14 - a4     - function argument 4                 */
+    rt_ubase_t a5;         /*!< x15 - a5     - function argument 5                 */
+#ifndef __riscv_32e
+    rt_ubase_t a6;         /*!< x16 - a6     - function argument 6                 */
+    rt_ubase_t a7;         /*!< x17 - s7     - function argument 7                 */
+    rt_ubase_t s2;         /*!< x18 - s2     - saved register 2                    */
+    rt_ubase_t s3;         /*!< x19 - s3     - saved register 3                    */
+    rt_ubase_t s4;         /*!< x20 - s4     - saved register 4                    */
+    rt_ubase_t s5;         /*!< x21 - s5     - saved register 5                    */
+    rt_ubase_t s6;         /*!< x22 - s6     - saved register 6                    */
+    rt_ubase_t s7;         /*!< x23 - s7     - saved register 7                    */
+    rt_ubase_t s8;         /*!< x24 - s8     - saved register 8                    */
+    rt_ubase_t s9;         /*!< x25 - s9     - saved register 9                    */
+    rt_ubase_t s10;        /*!< x26 - s10    - saved register 10                   */
+    rt_ubase_t s11;        /*!< x27 - s11    - saved register 11                   */
+    rt_ubase_t t3;         /*!< x28 - t3     - temporary register 3                */
+    rt_ubase_t t4;         /*!< x29 - t4     - temporary register 4                */
+    rt_ubase_t t5;         /*!< x30 - t5     - temporary register 5                */
+    rt_ubase_t t6;         /*!< x31 - t6     - temporary register 6                */
+#endif
+    rt_ubase_t mstatus;    /*!<              - machine status register             */
+};
+
+/**
+ * This function will initialize thread stack
+ *
+ * @param tentry the entry of thread
+ * @param parameter the parameter of entry
+ * @param stack_addr the beginning stack address
+ * @param texit the function will be called when thread exit
+ *
+ * @return stack address
+ */
+rt_uint8_t *rt_hw_stack_init(void       *tentry,
+                             void       *parameter,
+                             rt_uint8_t *stack_addr,
+                             void       *texit)
+{
+    struct rt_hw_stack_frame *frame;
+    rt_uint8_t         *stk;
+    int                i;
+
+    stk  = stack_addr + sizeof(rt_ubase_t);
+    stk  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_ubase_t)stk, REGBYTES);
+    stk -= sizeof(struct rt_hw_stack_frame);
+
+    frame = (struct rt_hw_stack_frame *)stk;
+
+    for (i = 0; i < sizeof(struct rt_hw_stack_frame) / sizeof(rt_ubase_t); i++)
+    {
+        ((rt_ubase_t *)frame)[i] = 0xdeadbeef;
+    }
+
+    frame->ra      = (rt_ubase_t)texit;
+    frame->a0      = (rt_ubase_t)parameter;
+    frame->epc     = (rt_ubase_t)tentry;
+
+    frame->mstatus = RT_INITIAL_MSTATUS;
+
+    return stk;
+}
+
+/**
+ * @brief Do rt-thread context switch in interrupt context
+ * 
+ * @param from thread sp of from thread
+ * @param to thread sp of to thread
+ */
+void rt_hw_context_switch_interrupt(rt_ubase_t from, rt_ubase_t to)
+{
+    if (rt_thread_switch_interrupt_flag == 0)
+        rt_interrupt_from_thread = from;
+
+    rt_interrupt_to_thread = to;
+    rt_thread_switch_interrupt_flag = 1;
+    RT_YIELD();
+}
+
+/**
+ * @brief Do rt-thread context switch in task context
+ * 
+ * @param from thread sp of from thread
+ * @param to thread sp of to thread
+ */
+void rt_hw_context_switch(rt_ubase_t from, rt_ubase_t to)
+{
+    rt_interrupt_from_thread = from;
+    rt_interrupt_to_thread = to;
+    RT_YIELD();
+}
+
+/**
+ * @brief shutdown CPU
+ * 
+ */
+void rt_hw_cpu_shutdown()
+{
+    rt_uint32_t level;
+    rt_kprintf("shutdown...\n");
+
+    level = rt_hw_interrupt_disable();
+    while (level)
+    {
+        RT_ASSERT(0);
+    }
+}
+
+/**
+ * @brief Do extra task switch code
+ * 
+ * @details
+ * 
+ * - Clear software timer interrupt request flag
+ * - clear rt_thread_switch_interrupt_flag to 0
+ */
+void rt_hw_taskswitch(void)
+{
+    /* Clear Software IRQ, A MUST */
+    SysTimer_ClearSWIRQ();
+    rt_thread_switch_interrupt_flag = 0;
+}
+
+/**
+ * @brief Setup systimer and software timer interrupt
+ * 
+ * @details 
+ * 
+ * - Set Systimer interrupt as NON-VECTOR interrupt with lowest interrupt level
+ * - Set software timer interrupt as VECTOR interrupt with lowest interrupt level
+ * - Enable these two interrupts
+ */
+void rt_hw_ticksetup(void)
+{
+    uint64_t ticks = SYSTICK_TICK_CONST;
+
+    /* Make SWI and SysTick the lowest priority interrupts. */
+    /* Stop and clear the SysTimer. SysTimer as Non-Vector Interrupt */
+    SysTick_Config(ticks);
+    ECLIC_DisableIRQ(SysTimer_IRQn);
+    ECLIC_SetLevelIRQ(SysTimer_IRQn, RT_KERNEL_INTERRUPT_LEVEL);
+    ECLIC_SetShvIRQ(SysTimer_IRQn, ECLIC_NON_VECTOR_INTERRUPT);
+    ECLIC_EnableIRQ(SysTimer_IRQn);
+
+    /* Set SWI interrupt level to lowest level/priority, SysTimerSW as Vector Interrupt */
+    ECLIC_SetShvIRQ(SysTimerSW_IRQn, ECLIC_VECTOR_INTERRUPT);
+    ECLIC_SetLevelIRQ(SysTimerSW_IRQn, RT_KERNEL_INTERRUPT_LEVEL);
+    ECLIC_EnableIRQ(SysTimerSW_IRQn);
+}
+
+/**
+ * systimer interrupt handler eclic_mtip_handler
+ * is hard coded in startup_<Device>.S
+ * We define SysTick_Handler as eclic_mtip_handler
+ * for easy understanding
+ */
+#define SysTick_Handler     eclic_mtip_handler
+
+/**
+ * @brief This is the timer interrupt service routine.
+ * 
+ */
+void SysTick_Handler(void)
+{
+    /* Reload systimer */
+    SysTick_Reload(SYSTICK_TICK_CONST);
+
+    /* enter interrupt */
+    rt_interrupt_enter();
+
+    /* tick increase */
+    rt_tick_increase();
+
+    /* leave interrupt */
+    rt_interrupt_leave();
+}
+
+/**
+ * @brief Disable cpu interrupt
+ * 
+ * @details
+ * 
+ * - Disable cpu interrupt by clear MIE bit in MSTATUS
+ * - Return the previous value in MSTATUS before clear MIE bit
+ * 
+ * @return the previous value in MSTATUS before clear MIE bit 
+ */
+rt_base_t rt_hw_interrupt_disable(void)
+{
+    return __RV_CSR_READ_CLEAR(CSR_MSTATUS, MSTATUS_MIE);
+}
+
+/**
+ * @brief Restore previous saved interrupt status
+ * 
+ * @param level previous saved MSTATUS value
+ */
+void rt_hw_interrupt_enable(rt_base_t level)
+{
+    __RV_CSR_WRITE(CSR_MSTATUS, level);
+}
diff --git a/libcpu/risc-v/nuclei/cpuport.h b/libcpu/risc-v/nuclei/cpuport.h
new file mode 100644
index 0000000000..3736f0078a
--- /dev/null
+++ b/libcpu/risc-v/nuclei/cpuport.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2006-2018, RT-Thread Development Team
+ * Copyright (c) 2019-Present Nuclei Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2020/03/26     hqfang       Nuclei RISC-V Core porting code.
+ */
+
+#ifndef __CPUPORT_H__
+#define __CPUPORT_H__
+
+#include <rtconfig.h>
+#include <nuclei_sdk_soc.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Scheduler utilities. */
+#define RT_YIELD()                                                              \
+{                                                                               \
+    /* Set a software interrupt(SWI) request to request a context switch. */    \
+    SysTimer_SetSWIRQ();                                                        \
+    /* Barriers are normally not required but do ensure the code is completely  \
+    within the specified behaviour for the architecture. */                     \
+    __RWMB();                                                                   \
+    __FENCE_I();                                                                \
+}
+
+extern void rt_hw_ticksetup(void);
+extern void rt_hw_taskswitch(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/libcpu/risc-v/nuclei/interrupt_gcc.S b/libcpu/risc-v/nuclei/interrupt_gcc.S
new file mode 100644
index 0000000000..02a3e3e760
--- /dev/null
+++ b/libcpu/risc-v/nuclei/interrupt_gcc.S
@@ -0,0 +1,218 @@
+/*
+ * Copyright (c) 2019-Present Nuclei Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2020/03/26     hqfang       First Nuclei RISC-V porting implementation
+ */
+
+#include "riscv_encoding.h"
+
+.section    .text.entry
+.align 8
+
+/**
+ * \brief  Global interrupt disabled
+ * \details
+ *  This function disable global interrupt.
+ * \remarks
+ *  - All the interrupt requests will be ignored by CPU.
+ */
+.macro DISABLE_MIE
+    csrc CSR_MSTATUS, MSTATUS_MIE
+.endm
+
+/**
+ * \brief  Macro for context save
+ * \details
+ * This macro save ABI defined caller saved registers in the stack.
+ * \remarks
+ * - This Macro could use to save context when you enter to interrupt
+ * or exception
+*/
+/* Save caller registers */
+.macro SAVE_CONTEXT
+    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 */
+.endm
+
+/**
+ * \brief  Macro for restore caller registers
+ * \details
+ * This macro restore ABI defined caller saved registers from stack.
+ * \remarks
+ * - You could use this macro to restore context before you want return
+ * from interrupt or exeception
+ */
+/* Restore caller registers */
+.macro RESTORE_CONTEXT
+    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
+.endm
+
+/**
+ * \brief  Macro for save necessary CSRs to stack
+ * \details
+ * This macro store MCAUSE, MEPC, MSUBM to stack.
+ */
+.macro SAVE_CSR_CONTEXT
+    /* 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
+.endm
+
+/**
+ * \brief  Macro for restore necessary CSRs from stack
+ * \details
+ * This macro restore MSUBM, MEPC, MCAUSE from stack.
+ */
+.macro RESTORE_CSR_CONTEXT
+    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
+.endm
+
+/**
+ * \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.
+ */
+.section .text.trap
+/* In CLIC mode, the exeception entry must be 64bytes aligned */
+.align 6
+.global exc_entry
+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 */
+    mret
+
+/**
+ * \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.
+ */
+.section      .text.irq
+/* In CLIC mode, the interrupt entry must be 4bytes aligned */
+.align 2
+.global irq_entry
+/* 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 */
+    mret
+
+/* Default Handler for Exceptions / Interrupts */
+.global default_intexc_handler
+Undef_Handler:
+default_intexc_handler:
+1:
+	j 1b
+