GD32V运行速度慢的解决方法

void _init()
{
	SystemInit();

	//ECLIC init
	eclic_init(ECLIC_NUM_INTERRUPTS);
	eclic_mode_enable();

	//printf("After ECLIC mode enabled, the mtvec value is %x \n\n\r", read_csr(mtvec));

	// // It must be NOTED:
	//  //    * In the RISC-V arch, if user mode and PMP supported, then by default if PMP is not configured
	//  //      with valid entries, then user mode cannot access any memory, and cannot execute any instructions.
	//  //    * So if switch to user-mode and still want to continue, then you must configure PMP first
	//pmp_open_all_space();
	//switch_m2u_mode();

    /* Before enter into main, add the cycle/instret disable by default to save power,
    only use them when needed to measure the cycle/instret */
	disable_mcycle_minstret();
}