_R_S0
uc.uc_mcontext.__gregs[_REG_S0] = sc->sc_regs[_R_S0];
{ "s0", (long *)&ddb_regs.r_regs[_R_S0], DB_SETF_REGS, NULL },
gdb_regs[16] = regs->r_regs[_R_S0]; /* S0 */
case _R_S0: /* s0 */
tf->tf_regs[_R_S0], tf->tf_regs[_R_S1], tf->tf_regs[_R_S2]);