CCS/TMS320F28035: Specific function in specific ROM

The general method has three steps.

1. Put all the functions of interest in input sections you name, instead of the default name .text. 
2. Collect all those input sections together into one output section
3. Allocate that output section in the desired memory range.

Step 1 is done in the C source.  Steps 2 and 3 are done in the linker command file.

Perform step 1 with #pragma SET_CODE_SECTION, or #pragma CODE_SECTION, or the GCC function attribute section.  You can read about the pragmas in the C2000 compiler manual.  GCC function attributes are documented in many places on the web.  For now, I presume you use the section name "serial_code".

In the linker command file, I presume you already have a memory range configured with the name FLASHB.  In that case, in the SECTIONS directive, you can write ...

    serial_code > FLASHB

This one line performs steps 2 and 3.  All the input sections named "serial_code" are collected together into an output section also named "serial_code".  Then that output section is allocated to the memory range named FLASHB.

To understand steps 2 and 3 better, please see the article Linker Command File Primer.

Thanks and regards,

-George