Re: [Qemu-devel] How to split vl.h

[Paul Brook]

On Sunday 04 November 2007, J. Mayer wrote:
> On Sun, 2007-11-04 at 12:17 +0000, Paul Brook wrote:
> > > I have another solution: include all architecture specific files from
> > > the main file.
> >
> > I'd really rather not do this. I doubt it's going to be a win, as now you
> > have to recompile the whole thing every time you change the
> > implementation. At least with vl.h you only have to recompile when you
> > change the interface.
>
> What I feel about this is that adding a hw/hw.h, included in all hw/*.c
> files would greatly improve the situation: changing vl.h would lead to
> recompile the core emulator object files, changing hw/hw.h would lead to
> recompile the hardware library.

Well, most of the "core emulator" doesn't depend on vl.h anyway. It's just the 
device emulation and host disk/display code.

I not sure a single hw/hw.h file will give any benefit because there's a fair 
amount of interfacing between the target devices emulation and the host side 
interaction code. i.e. there's not much that's only used inside hw/.
hw/ is about as big as most of the rest of qemu put together, so splitting 
that is probably going to get the biggest wins.

How about dividing things up by category? e.g. Have header files for all of 
(in no particular order):

- Things includes by everything
- The block IO layer.
- The character IO layer
- Network IO layer.
- Display interface.
- Generic Device infrastructure (memory mapping, IRQs, etc). Maybe subdivide 
for common busses like scsi/usb/pci/i2c.
- Prototypes for device emulation init routines.

Each file can then include whichever categories it needs.

Paul