Compiler/TM4C1294NCPDT: GPIO_setCallback crashing

Richard Robinson

Part Number: TM4C1294NCPDT

Tool/software: TI C/C++ Compiler

Hi,

I have an interrupt service routine for an I/O pin the address is the ISR is 0x0001A628. When I look at the disassembly, we have the following:-

000085c6: 494A ldr r1, [pc, #0x128]
000085c8: 2000 movs r0, #0
000085ca: F00EF8CF bl #0x1676c

Using the memory browser to look a PC+0x128 the constant stored in the literal pool is 0x0001A629. Is this a compiler error.

Strangely if I populate the callback structure with the address of my ISR this works and the correct address is populated.

Thanks,

Richard.

over 8 years ago

0 Charles Tsai over 8 years ago

TI__Guru**** 191486 points

Hi Richard,
Are you saying the bl #0x1676c is causing the the code to crash?

0 Richard Robinson over 8 years ago in reply to Charles Tsai

Intellectual 730 points

Hi,

No. What I am saying is the compiler is placing 0x0001A629 into the literal pool instead of 0x0001A628 which is the actual address of the ISR.

000085c6: 494A ldr r1, [pc, #0x128]
000085c8: 2000 movs r0, #0
000085ca: F00EF8CF bl #0x0001A629

Richard.

0 Robert Adsett over 8 years ago in reply to Richard Robinson

Guru 27665 points

Perhaps it's set to 9 rather than 8 because it's Cortex and all calls have the low bit set to indicate a thumb call?

I seem to recall that for Cortex that's true for the interrupt table as well. Hmm, I did just check my interrupt table and that appears to be the case.

Robert

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Compiler/TM4C1294NCPDT: GPIO_setCallback crashing