Dear All,
Now I'm trying to trace the root cause of HardFault Cortex M3 with .lst and tarmac0.log files.
Currently problem is that I'm not sure how to trace the root cause when I come across HardFault.
In especially, I'm wonder that does disassembly code help us to trace the root cause?
UartPutc((char) DBG_ESCAPE); //send ESCAPE code 2da: 201b movs r0, #27 2dc: f000 f8aa bl 434 <UartPutc> UartPutc((char) DBG_CONNECT_ENABLE); //send debug test enable command 2e0: 2011 movs r0, #17 2e2: f000 f8a7 bl 434 <UartPutc> puts("\nEnabling debug tester...\n"); 2e6: 4810 ldr r0, [pc, #64] ; (328 <EnableDebugTester+0x60>) 2e8: f000 fa8e bl 808 <puts> // If debug tester is not present, if((CMSDK_GPIO0->DATA & DEBUG_ERROR) != 0) 2ec: 6823 ldr r3, [r4, #0] 2ee: 045b lsls r3, r3, #17 2f0: d405 bmi.n 2fe <EnableDebugTester+0x36> // (Zero the 4 words above Stack Top) // for(i=0; i<4 ; i++) { puts("\nInitialise the Communication Region...\n"); 2f2: 480e ldr r0, [pc, #56] ; (32c <EnableDebugTester+0x64>) 2f4: f000 fa88 bl 808 <puts> DEBUGTESTERDATA[i] = 0; //<================================HERE 2f8: 2300 movs r3, #0 2fa: 681b ldr r3, [r3, #0] 2fc: deff udf #255 ; 0xff UartPutc((char) DBG_CONNECT_ENABLE); //send debug test enable command puts("\nEnabling debug tester...\n"); // If debug tester is not present, if((CMSDK_GPIO0->DATA & DEBUG_ERROR) != 0) { puts("DBGERROR bit (debug error) asserted.\n"); 2fe: 480c ldr r0, [pc, #48] ; (330 <EnableDebugTester+0x68>) 300: f000 fa82 bl 808 <puts> puts("Debug tester not available:\n"); 304: 480b ldr r0, [pc, #44] ; (334 <EnableDebugTester+0x6c>) 306: f000 fa7f bl 808 <puts> puts("1: The ARM_CMSDK_INCLUDE_DEBUG_TESTER macro is not defined, or\n"); 30a: 480b ldr r0, [pc, #44] ; (338 <EnableDebugTester+0x70>) 30c: f000 fa7c bl 808 <puts> puts("2: Cortex-M0 DesignStart is used\n"); 310: 480a ldr r0, [pc, #40] ; (33c <EnableDebugTester+0x74>) 312: f000 fa79 bl 808 <puts>
As you can see the above code, I come across "Unexpected Hard Fault", when DEBUGTESTERDATA[i] = 0; run after.
Would you help me what am I supposed to do to resolve this problem?
DEBUGTESTERDATA[i] = 0; //<================================HERE 2f8: 2300 movs r3, #0 2fa: 681b ldr r3, [r3, #0] 2fc: deff udf #255 ; 0xff
The "udf #255" will generate an "undefined instruction exception" (part of the Usage Fault) If the Usage Fault is not enabled, it will generate a Hard Fault.
This is clearly being done on purpose so you either need to enable the Usage Fault Handler and handle this undefined instruction or Handle it in the Hard Fault Handler.
You are likely using other code (linking in) that is counting on a certain behavior when the udf #255 instruction is being executed and it is not happening so you get a hard fault rather than proper behavior.
Thanks for replying that.
I'm wondering that I came across that HardFault error when I compiled with gcc as the below.
arm-none-eabi-gcc --version arm-none-eabi-gcc (GNU Tools for ARM Embedded Processors) 4.9.3 20150529 (release) [ARM/embedded-4_9-branch revision 227977] Copyright (C) 2014 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Today, I just found that in DS-5 environment, that point have some warning as warning: indirection of non-volatile null pointer will be deleted, not trap You can see here. https://imgur.com/a/roZjK and DEBUGTESTERDATA is defined like
#define DEBUGTESTERDATA ((volatile uint32_t *) *((uint32_t *) 0x0))
ans that defined like this https://imgur.com/a/3ZGo1
Might be gcc environment can't handle like this warning but I'm not sure.
Today, I found that in DS-5 environment the compile and simulation are more likely to have success without HardFault error.
Would you help me how to resolve this problem in gcc compile environment?
This is the Keil forum - for discussions about Keil products. http://www.keil.com/forum/
GCC is not a Keil product!
>>Would you help me
I'm open to offers for my time.