How do I declare an array in a different segment?

[dporada]

In CodeWarrior, I did this:

#pragma define_section my_ram2 ".display" abs32 RW

__declspec(section "my_ram2") uint8 Display[511];

This does not work in KDS.  I get an error saying that Display is undeclared.

Please help.

[Jorge_Gonzalez]

Hello Donald:

The response by colleague Derek Snell is correct, you need __attribute__ ((section (...) )), and modify the linker file as necessary.

There are some tutorials and code examples about this:

Defining Variables at Absolute Addresses with gcc | MCU on Eclipse

Relocating Code and Data Using the CW GCC Linker File for Kinetis

Re: Controlling data and function placement in memory

Re: Re: Syntax to allocate memory assignments to faster memory

Regards!

Jorge_Gonzalez

[dereksnell · Accepted solution]

Hi Don,

If you’d like to see how the GCC build tools in KDS can do this, you can use KDS to create a new project, and use it as an example. The interrupt vector table is forced to a specific memory section. I created a project with Processor Expert for the K64, and in vectors.c, the line below forces the vector table array into the .vectortable memory section. You can also review the linker file *.ld added to the project to see how .vectortable is used in the linker file.

__attribute__ ((section (".vectortable"))) const tVectorTable __vect_table = { /* Interrupt vector table */