topic Re: K70_Unhandled Exception : Hardfault in Kinetis Microcontrollers

K70_Unhandled Exception : Hardfault

chiranjeevn — Sun, 19 Jul 2015 15:00:42 GMT

Dear All,

Please assist me to solve the issue K70_Unhandled Exception : Hardfault in K70 Module.Please find the attachment herewith .

Regards

Chiranjeev N

Re: K70_Unhandled Exception : Hardfault

yasuhikokoumoto — Sun, 19 Jul 2015 21:27:20 GMT

Hello,

do you develop a u-boot for K70?

What is the instruction at the erroneous PC 0x8b92?

Generally speaking, HardFault sometimes happens by accessing un-clocked peripherals.

Please check it.

Best regards,

Yasuhiko Koumoto.

Re: K70_Unhandled Exception : Hardfault

chiranjeevn — Mon, 20 Jul 2015 08:37:38 GMT

Thanks Yasuhiko Koumoto,

Please find my answers below

do you develop a u-boot for K70?

i am not developing u-boot (u-boot code which came with the BSP , which am using the same without any change)

What is the instruction at the erroneous PC 0x8b92?

S214008B9004B0BDE8F08E602934D07029F8D1019871

this is the line i found from uboot.srec file, also attached the screen shot of uboot.srec.

HardFault sometimes happens by accessing un-clocked peripherals.

I am not controlling any clock (system clock,bus clock,peripheral clock) up to booting process is over,This is controlled by the u-boot and kernel .

Once the system is booted I am trying to access peripherals from user space .

Please correct me if my answers are not acceptable.

Re: K70_Unhandled Exception : Hardfault

chiranjeevn — Fri, 24 Jul 2015 07:07:39 GMT

Thanks Yasuhiko Koumoto

Generally speaking, HardFault sometimes happens by accessing un-clocked peripherals?

I am not aware on this ,please explain.

Please assist.

Re: K70_Unhandled Exception : Hardfault

peterruesch — Fri, 24 Jul 2015 07:34:46 GMT

this is a common behavior across multiple ARM devices.

You have to enable the gated clock to a peripheral before you access it's registers.

I'm very happy when my hardfaults get resolved this way :smileyhappy: it's a nice bug :smileywink:

Re: K70_Unhandled Exception : Hardfault

yasuhikokoumoto — Fri, 24 Jul 2015 08:28:27 GMT

Hello Chiranjeev N,

did you follow the procedure of https://www.emcraft.com/docs/linux-TWR-K70F120M-bspg-1.12.0.pdf ?

If you did so, I would be helpless.

Best regards,

Yasuhiko Koumoto.

Re: K70_Unhandled Exception : Hardfault

yasuhikokoumoto — Fri, 24 Jul 2015 20:50:40 GMT

Hello Chiranjeev N,

this is additional information.

The dis-assemble of the code "S214008B9004B0BDE8F08E602934D07029F8D1019871" is as below.

00000000 <foo>:
  0:  b004            add    sp, #16
  2:  e8bd 8ef0      ldmia.w sp!, {r4, r5, r6, r7, r9, sl, fp, pc}
  6:  2960            cmp    r1, #96 ; 0x60
  8:  d034            beq.n  74 <foo+0x74>
  a:  2970            cmp    r1, #112        ; 0x70
  c:  d1f8            bne.n  0 <foo>
  e:  9801            ldr    r0, [sp, #4]

According to the code, I guess that the hard fault had happened by un-initialized stack pointer or stack overflow.

Best regards,

Yasuhiko Koumoto.