RTT+stm32使用freemodbus的tcp模式报错怎么解决啊？

使用了官方提供的freemodbus测试代码。
使用最新的rt-thread源码
请问下面的问题，怎么排查解决啊？
我尝试了修改官方例程，增大了栈的大小，但是依旧报错

msh />mb_slave_samlpe TCP
[E/tcpserv] thread create failed
[E/tcpserv] tcp server start failed
[E/tcpserv] error!
psr: 0x41000000
r00: 0x00000000
r01: 0x08027879
r02: 0x0000382c
r03: 0xffffffff
r04: 0x000001f6
r05: 0x00000000
r06: 0xdeadbeef
r07: 0xdeadbeef
r08: 0xdeadbeef
r09: 0xdeadbeef
r10: 0xdeadbeef
r11: 0xdeadbeef
r12: 0x0801d039
lr: 0x08028c7d
pc: 0x08028c7c
hard fault on thread: md_s_pol
thread pri status sp stack size max used left tick error

md_s_pol 10 running 0x00000044 0x00000400 52% 0x0000000a OK
tshell 20 ready 0x000000dc 0x00001000 08% 0x00000008 OK
tcpip 10 suspend 0x000000c4 0x00000400 71% 0x00000011 OK
etx 12 suspend 0x00000090 0x00000400 36% 0x0000000e OK
erx 12 suspend 0x00000090 0x00000400 40% 0x00000005 OK
sys work 23 suspend 0x0000005c 0x00000800 21% 0x0000000a OK
tidle0 31 ready 0x00000044 0x00000100 39% 0x00000016 OK
main 10 suspend 0x00000080 0x00000800 31% 0x00000009 OK
bus fault:
SCB_CFSR_BFSR:0x04 IMPRECISERR