Subversion Repositories neorv32

/**********************************************************************//**

 * Switch from privilege mode MACHINE to privilege mode USER.

 *

 * @note This function requires the U extension to be implemented.

 **************************************************************************/

void __attribute__((naked)) neorv32_cpu_goto_user_mode(void) {

  register uint32_t mask = (1<<CPU_MSTATUS_MPP_H) | (1<<CPU_MSTATUS_MPP_L);

  mask = ~mask;

  asm volatile ("csrrc zero, mstatus, %[input_j]" :  : [input_j] "r" (mask));

  // return and switch to user mode

  asm volatile ("csrw mepc, ra");

  asm volatile ("mret");

}