Posted on July 11, 2018 at 00:28I have been struggling for several days now to track down a hard fault I am getting in one of my programs. It seems to be related to printf (and similar) functions.
After running for a while I will get a hardfault from __vprintf_float_long_long(). Unfortunately that is where the stack trace stops. The fault type varies, sometimes it doesn't even fault, it just gets stuck in __vprintf_float_long_long never to return.
Sometimes I get BFARVALID=1, and PRECISERR=1, and BFAR=0xFFFFFFFF. Sometimes I get INVSTATE=1.
Presently, I have a fault on these lines:
F7FCF8B9 bl 0x08035B24 <__RAL_pre_padding>
9704 str r7, [sp, #16]
463A mov r2, r7
4641 mov r1, r8
2030 movs r0, #0x30
F7FCF8A5 bl 0x08035B08 <__RAL_print_padding>
1E63 subs r3, r4, #1
9305 str r3, [sp, #20]
D40D bmi 0x080399E0
AF0D add r7, sp, #0x34
443C add r4, r7
F8DD8010 ldr.w r8, [sp, #16]
F8141D01 ldrb r1, [r4, #-1]! <--Faulted from here
4640 mov r0, r8
F7FCF87F bl 0x08035AD4 <__putc>
I have r1=0x20001780 and r4=0
I am using rowley crossworks V4.0 with their tasking library. My processor is an STM32F446. I have hardfloat enabled.
I have check my stacks and confirmed there is no overflow. I have tried mutexing access to printf, replacing printf with vsnprintf, and many other things. Is there something I can do to get more meaningful debug data? Are there any know problems with gcc libraries that might explain what is going wrong? Please help!
