SK-AM62A-LP: .asm offsetof and sizeof reference issue

Naveen Kumar

Part Number: SK-AM62A-LP

Hello Team,

We tried of adding inline asm for calculating the OffsetOf in the .c file as below and it was working for us.

#define OsOffsetOf(type, member) __builtin_offsetof (type, member) //((osuint16) &(((structure *) 0)->member))

Inline asm :

__asm__("mov r1, %c0" : : "i" (OsOffsetOf(OsCtrlParamType, ActiveTaskIndex)));

compiler cmake define :

-D_CRT_USE_BUILTIN_OFFSETOF

If we try to add this code in assembly file we are facing errors and it is not successful.

So is there any equivalent code for calculating this OffsetOf and sizeof for a structure defined in .h file from the assembly file.

Please provide your feedback in this.

Thanks and Regards,

Naveen

0 George Mock over 1 year ago

I presume you use the LLVM/Clang based Arm compiler from TI. The short name is tiarmclang.

Naveen Kumar said:
is there any equivalent code for calculating this OffsetOf and sizeof for a structure defined in .h file from the assembly file.

Unfortunately, no.

Thanks and regards,

-George

0 Krithika Ravi over 1 year ago in reply to George Mock

Hello Naveen,

As George mentioned, this is not supported. The options are:

Use inlined assembly in a C file as alreadydone. This allows fairly seamless mixing of C and assembly code.
Place the OffsetOf definition (or sizeof()) in a function in a C file that can be called from the assembly file (and link against it).
Define an assembly macro in the assembly file (or assembly header file) using hand-coded assembly to do whatever is required..

Regards,
Krithika

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