Comments on: links

By: Good boy

Good boy — Tue, 23 Sep 2008 14:32:23 +0000

Anyway, you help me much.
I like your tonic.

Maybe I have still have a lot of question to ask you in the future. :)
Please don’t be annoyed with me for asking these questions which maybe you think so easy.

By: cearn

cearn — Mon, 22 Sep 2008 17:06:18 +0000

To be honest, I’m not sure what -g does exactly for the object (and ELF) files, but it seems to do something. I do know what effect it has on the generated assembly: it adds .loc directives everywhere. These seem to carry the line number in the source code, presumably to be used for breakpoints. For more details you’ll have to go to the manual I’m afraid.

By: Good boy

Good boy — Sun, 21 Sep 2008 14:21:38 +0000

Thank Cearn very much! Your answer helps me so much!

But I still have one question. As you said, part of the extra information in the ELF file is debugger information, which could be helpful when running with gdb. I remember that the “-g” option of GCC on Linux platform can produce extra debugging information. What is the different between these two commands “gcc -g -o file file.c” and “gcc -o file file.c” in Linux OS? Does the ELF file contain more debugging information if you add “-g” option when you complie the source codes?

Thank you so much.

By: cearn

cearn — Sun, 21 Sep 2008 11:07:21 +0000

An ELF file is the general file format that GCC uses for tis binary output. The object files (.o) are also ELF files, but with a different extension. ELF file don’t just contain the real bits of the program but also link-section information, function names, and a host of other things. If you compare the file sizes of an ELF and its GBA file, you’ll see that the ELF is much bigger.

The GBA does not expect all that extra stuff and doesn’t know what to do with it. In other words, it wouldn’t run. The objcopy tool strips all the excess information.

I think there’s a linker flag that strips the binary down to the raw bits and bytes, but I’ve never really examined what it does. Also, part of the extra information in the ELF file is debugger information, which could be helpful when running with gdb.

By: Good boy

Good boy — Sat, 20 Sep 2008 11:50:08 +0000

Dear Cearn,
I have one question about GBA programming. why a *.elf file is made before a *.gba file made? what is the relationship between them? Thanks.

By: Good boy

Good boy — Tue, 05 Feb 2008 08:03:02 +0000

Tonc is a wonderful tutorial!!

By: one person

one person — Fri, 30 Nov 2007 15:00:49 +0000

Now I realize why I counld not access to http://www.gbadev.org in the pass. I can deal with this by useing proxy.
Thank you for your comments.(My English is not good. There may be some mistakes here.Please forgive me.)

By: cearn

cearn — Sun, 18 Nov 2007 20:12:30 +0000

http://www.gbadev.org works fine from here. Could have been a temporary glitch.

By: one person

one person — Fri, 16 Nov 2007 18:59:37 +0000

Why I can’t open http://www.gbadev.org ? Have it changed website?