Upload hello program successful but error output of UART

Open On-Chip Debugger 0.10.0+dev (SiFive OpenOCD 0.10.0-2019.05.1)
Licensed under GNU GPL v2
For bug reports:
https://github.com/sifive/freedom-tools/issues
adapter speed: 10000 kHz
Info : auto-selecting first available session transport “jtag”. To override use 'transport select '.
Info : ftdi: if you experience problems at higher adapter clocks, try the command “ftdi_tdo_sample_edge falling”
Info : clock speed 10000 kHz
Info : JTAG tap: riscv.cpu tap/device found: 0x20000913 (mfg: 0x489 (SiFive, Inc.), part: 0x0000, ver: 0x2)
Info : datacount=1 progbufsize=16
Info : Disabling abstract command reads from CSRs.
Info : Examined RISC-V core; found 1 harts
Info : hart 0: XLEN=32, misa=0x40001105
Info : Listening on port 3333 for gdb connections
Info : Found flash device ‘micron n25q128’ (ID 0x0018ba20)
cleared protection for sectors 64 through 255 on flash bank 0
Ready for Remote Connections
Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Info : accepting ‘gdb’ connection on tcp/3333
0x204029a2 in metal_shutdown ()
Info : JTAG tap: riscv.cpu tap/device found: 0x20000913 (mfg: 0x489 (SiFive, Inc.), part: 0x0000, ver: 0x2)
JTAG tap: riscv.cpu tap/device found: 0x20000913 (mfg: 0x489 (SiFive, Inc.), part: 0x0000, ver: 0x2)
cleared protection for sectors 64 through 255 on flash bank 0
cleared protection for sectors 64 through 255 on flash bank 0
Info : JTAG tap: riscv.cpu tap/device found: 0x20000913 (mfg: 0x489 (SiFive, Inc.), part: 0x0000, ver: 0x2)
Loading section .init, size 0x188 lma 0x20400000
Loading section .text, size 0x28ba lma 0x20400200
Loading section .rodata, size 0x254 lma 0x20402abc
Loading section .init_array, size 0x8 lma 0x20402d10
Loading section .data, size 0x778 lma 0x20402d18
Info : Padding image section 0 at 0x20400188 with 120 bytes
Info : Padding image section 1 at 0x20402aba with 2 bytes
Info : Disabling abstract command writes to CSRs.
Info : JTAG tap: riscv.cpu tap/device found: 0x20000913 (mfg: 0x489 (SiFive, Inc.), part: 0x0000, ver: 0x2)
Start address 0x20400000, load size 13334
Transfer rate: 1001 bytes/sec, 2666 bytes/write.
shutdown command invoked
shutdown command invoked
A debugging session is active.

After pressing reset button ,there are some strange output of UART like
?榝<酁酁䴙鄦榝鬄?酁`<
Where can the problem occur?
How to find and solve it?

Have you checked that the baudrate of your USB port is set correctly?

I change the baudrate from 115200 which set by sifive arty-e310-getting start document to 57600 and it works Thanks :slightly_smiling_face: