PSL_SE
#define db_clear_single_step(regs) ((regs)->srr1 &= ~PSL_SE)
#define db_set_single_step(regs) ((regs)->srr1 |= PSL_SE)
tf->srr1 |= PSL_SE;
tf->srr1 &= ~PSL_SE;
#define db_clear_single_step(regs) ((regs)->srr1 &= ~PSL_SE)
#define db_set_single_step(regs) ((regs)->srr1 |= PSL_SE)
tf->srr1 |= PSL_SE;
tf->srr1 &= ~PSL_SE;