why printf only writes one byte to UART (Detected on the scope) then hardfault

[Paul]

I haven't used printf for a while. Today I am trying to write some code for UART. but it can only send the first byte of the string to the port according to the scope, then causes hardfault. I am using keil. I had solved similar "one byte only" issue before, but have no memory of what I did at that time. Someone can shine any light on me. Under pressure to write a test tool right now...

Thanks

[Jenson]

I still meet the issue that only printf one bytes: t while printf("test "); Could anyone helps?