Separate Vectors from .text

RE: Separate Vectors from .text

George Beckstien — Thu, 01 Feb 2018 16:42:23 GMT

Yes, I based it off of what you provided me. Thank you. I didn't want to just replace the files given by mbed though. I have enough issues with mbed as it is already 😅

RE: Separate Vectors from .text

Nguyen Hoan Hoang — Mon, 29 Jan 2018 16:50:57 GMT

That is exactly what is in the code I gave you initially in the EHAL library.

RE: Separate Vectors from .text

George Beckstien — Mon, 29 Jan 2018 15:22:53 GMT

From documentation here the naked .text directive tells the assembler to place the following code at the beginning of the code .text section.

The startup assembly is unmodified from the mbed version. I have achieved my desired code placement in a slightly different way and have detailed it in my original post.

RE: Separate Vectors from .text

RK — Fri, 26 Jan 2018 23:49:46 GMT

You have properly put

.section .Vectors

at the top to switch to the .Vectors section. However you need to switch out of it again back to .text before you define the Reset_handler (else it won't actually go into a section because it won't match anything). However you've just put

.text

not

.section .text

to do that. I suspect if you check the linker map file you'll find some/lots/at least Reset_handler marked as in the vectors section .Vectors.Reset_handler and discarded.

I don't even know what a naked .text. does in the middle of the file, you'd expect a linker warning.

Switch the section properly and see if that improves life. If it doesn't, hit the map file and start seeing what the linker is doing on a trivial example.

RE: Separate Vectors from .text

Nguyen Hoan Hoang — Fri, 26 Jan 2018 20:11:52 GMT

It should work with mBed as it works with the SDK. The code shows you how to separate Vector from the code and it also have received section just bellow the vector as you wanted. Just replace the mBed startup with that all the rest of the SDK is the same.

RE: Separate Vectors from .text

George Beckstien — Fri, 26 Jan 2018 19:49:57 GMT

Thank you, but that's not exactly what I'm looking for. I'm trying to modify the mbed startup code/linker files as little as possible to keep mbed stable.

I have updated the post with my attempts

RE: Separate Vectors from .text

Nguyen Hoan Hoang — Fri, 26 Jan 2018 19:26:03 GMT

What you need is available in the EHAL library. The startup code 100% in C no assembly require. The startup code work with all Cortex-M series M0-M4. Linker script is there too. Generic startup code, look for ResetEntry.c & gcc_arm_flash.ld in ARM/src. For Vectors look in src of specific platform for example nRF52 is Vectors_nRF52.c in ARM/Nordic/nRF52/src.