Microchip xc16 and section "__c30_signature"

[gtackett]

Object modules produced by the xc16 compiler, as well as those in the libraries, include a section called __c30_section. (I think it has something to do with debugging...)

I extracted some of the individual modules from liblega-pic30-elf.a and loaded a few of them individually in Ghidra. In them, I find the section __c30_section located at ram:0062. That's misleading, because the low addresses in ram actually are reserved, and ram:0062 happens to fall within the processor's alternate interrupt vector table.

But in executable files produced by the xc16 linker, the section shows up in the address space OTHER.

Maybe @ghidra1 will have some ideas here?

[ghidra1]

I suggest you try setting the base offset import option for such object modules which may not compute a good default base address.

[gtackett]

That should work for a single object module. The Microchip libraries contain thousands. I've been doing batch imports interactively, and (as probably makes sense) there's no option available there to specify a single base address for every module.

Maybe there's a headless way to import modules in bulk and specify options like base address? I'll try to figure it out myself, but a guru can probably quickly tell me how here, where it will be findable by other users.

[ghidra1]

You can use -loader-imagebase option with headless command line

[gtackett]

-loader-dataImagebase is actually the one I need, since c30_section gets loaded into a memory block inram:.

This does allow me to get __c30_section out of the way of the predefined registers, etc., in low memory.

Is there a way, as part of a headless import, to load a given section at a specified address and address space?

Say, for example, I'd like c30_section to go at OTHER:00001000. With a little work I could write my own script to re-create c30_section at that address, but I'd like to avoid that, if there's already an easier way.

[ghidra1]

No. We only support a single image base for the default and data spaces. All overlays in the OTHER space are expected to start at 0 since they do not represent a loaded section and only correspond to non-loaded file data.

[gtackett]

Sounds like time for a little scripting!