DRBL_HANDSHAKE
iowrite32(DRBL_HANDSHAKE, regs->pciea_to_arm_drbl_reg);
iowrite32(DRBL_HANDSHAKE, regs->pciea_to_arm_drbl_reg);
iowrite32(DRBL_HANDSHAKE, regs->pciea_to_arm_drbl_reg);
DRBL_HANDSHAKE_ISR = DRBL_HANDSHAKE,