Re: Getting started with building a GCC cross-compiler

[Duane Ellis <duane-gcc-help at duaneellis dot com>]

Dave Nadler wrote:> [microchip pic32 gcc - rebuild to support C++]

duane> Second, you'll need to look at your DEBUG options - they are not 
using GDB - and there is *some* *limited* support for ejtag in OpenOCD.

dave>I expect (hope ?) to use GDB via JTAG. Proof of concept here is 
using the ICD programmer but the MPLAB stuff will never support C++...

Well, when you are ready for OpenOCD - you can convert most "arm" (usb 
ftdi based) jtag dongles via an adapter cable.
You'll find me on the OpenOCD list when you get that far.

duane> Third, if I remember correctly gcc-pic32 has many #pragma hacks- 
that get picked up by the linker later on - and handles the bare metal 
chip initialization stuff.

dave> Exactly; this is one of the reasons I'd like to rebuild their 
version rather than move to a 3rd party version (the 3rd parties don't 
support the Microchip extensions, leading to a different set of problems).

Generally, what these #pragma items appeared to be is data that is 
stuffed into a special ELF segment - which - the Linker knows about - 
and based on that - information - the startup code can find / figure out 
how to initialize the chip registers out of a data table.

You might also ask these types of questions over on the "cross-gcc" list.

-Duane.