GBA + FPC = Possiblility???

[savage]

So can FPK or anyone else clarify if it is a compiler or linker or both?

FPK, are you able to give any rough estimates on the time it would take to make a change to either the compiler or linker to support the crt0.s/crt0.o issue?

Also how much money would it take for you to give up your day job and to work on FPC full time .

[Lightning]

Much, much, money !!! (medical equipment, hi-tech stuff, verry well payed)

FPC must be able to run/compile on/for your CPU and the RTL must be compatible with the OS

I still think you should contact him on #fpc or #lazarus-ide (irc.freenode.org)

PS: FPK doesn't like talking too much, it leaves no time to code

[WILL]

Well the idea isn't to overload FPK, who has actually taken the time out of an interest in the idea purposed, with all kinds of spin-off ideas. That'll land us with nothing. :?

The memory access/pointers, linker and THUMB instructions issues need to be addressed and should be checked out well first hand. Noeska has done some great work so far. And I'll provide what I can.

I think it would be a much needed aspect of FPC to help it gain popularity.

[FPK]

If you know what to do, it takes one evening to add the gba as new target to the compiler. FPC uses the GNU Binutils to assemble and link, so it's mainly telling the compiler which asm and linker to use.

The next step is to make an rtl, another 1-2 evenings I guess.

Then 3-4 days debugging.

Now the hard part comes: maintain the port, i.e. handle bug reports, adapt it to compiler/rtl changes etc. This is little work, but requires permenant interest and it's the reason why ports like BeOS, NetBSD or OpenBSD died. Nobody maintained them.

However, this doesn't address the thumb problem, I don't know if the gdb needs thumb code or not.

[noeska]

unfortunately i do not know how to add an port to free pascal. Trying to understand what is going on with linking gives me an headache. To spoiled with delphi i gues. It obviously is not as easy as linking in crt0.o.

If only the first part is done e.g. that the crt0 part is linked in correctly and starts the 'main' procedure. I can continue with my efforts, but without that i cannot continue. My developement pace is slow, i am trying to spend 1 hour evenings on it.

I have already downloaded a snapshot of free pascal, but i have no clue where to begin changing. e.g. the fakertl looks a place to start with rtl developement. But where should it go to?

So what is need to go on is:
A barebones freepascal compiler that proprly links in crt0.s. for the gba target. Or step by step instruction how to so from the cpp version.

Once again the link to how it is done for gnu cpp: http://linux.gbadev.org/gcc-gba/

[WILL]

FPK: There is an excellent book that covers ARM7 in one of it's chapters, though it is written for C programmers, I'm sure you'll be able to get some of what you need from it.

Here is the link to the book: http://www.jharbour.com/gameboy/default.aspx

You are looking for Chapter 11 - 'ARM7 Assembly Language Primer'.

I have also found Mr. Harbour to be quite responsive to topics discussed in his book and he knows Pascal aswell, perhaps he might be able to help with directly asked technical questions.

[Anonymous]

Why not try to make a gnu pascal cross compiler? Maybe it could be easier than fpc :?:

[Legolas]

Why not try to make a gnu pascal cross compiler? Maybe it could be easier than fpc :?:

Urgh... I'm sorry... I forgotten to logging in... ops:

[WILL]

GNU Pascal is not a pure compiler... It's only an extension to GCC.

However... that doesn't rule it out. But, I personally would rather work with FPC since it is more capable and open. Which means much better support and control.

As a side-advantage the GBA roms might even end up being smaller.

[Legolas]

Anyway I downloaded some documentation and sources... I think I'll try to make it, waiting for a freepascal crosscompiler. :rambo: