MSP430FR2355: Fail to communicate with BSL via UART

I read few documents about BSL, I try enter BSL via below code or control RST & TEST pin, I think it works because the firmware stop running. But I fail to communicate with BSL via UART.

__disable_interrupt(); // disable interrupts
((void (*)())0x1000)(); // jump to BSL

I have two questions:

1.Does BSL use UART0 (P1.6,P1.7) or UART1(P4.2,P4.3)?

2.Are there any tool which program MSP-EXP430FR2355 Launch Pad with eZ-FET debug probe via BSL instead of Spy-Bi-Wire so I can monitor the signals during the process?

Thanks a lot!