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Hey everyone, I'm new to this forum and I searched it as much as I could, so just go easy on me.

I'm also new to OS Development. I've started developing a 32Bit OS with a protected mode kernel with the help of the tutorials from the Bona Fide OS development Tutorials.

Here are my problem:

1. I can't decide which executable file format to use. If I wanted to use ELF, will I be able to compile sources under DOS/Windows with DJGPP 2?

2. Which filesystem is the best and easiest to implement and how can I do it?

3. I also would like to add a GUI to my OS, but I need a Memory Manager which I have no idea how to write. I did read Tim Robinson's tutorials, but due to my lack of knowledge in assembly, I cannot start writing it from scratch.

So, with those questions asked, I would appreciate any help from you guys.

Thanks.

emilsoft wrote:1. I can't decide which executable file format to use. If I wanted to use ELF, will I be able to compile sources under DOS/Windows with DJGPP 2?

Yes, in theory, but it takes a bit of setting up. However, if you do development under Windows, you can link to ELF indirectly (by linking to PE then using objcopy to convert to ELF).

COFF is a nice, simple format which is widely supported by tools and easy to load.

2. Which filesystem is the best and easiest to implement and how can I do it?

Best file system: there are lots of different answers to that...
Easiest file system to implement: well, reading from FAT is pretty easy.

3. I also would like to add a GUI to my OS, but I need a Memory Manager which I have no idea how to write. I did read Tim Robinson's tutorials, but due to my lack of knowledge in assembly, I cannot start writing it from scratch.

Right, first of all: forget about a GUI for at least the next year. There's a lot of work to be done before you can get to that stage.

About the memory management: well, unless you have a more specific question, I can't really say more other than "read the tutorials". Any advice I can give will be in there.

Thanks a lot for your reply.
But how do I implement FAT Filesystem into my OS?

And my Question about the Memory Manager is, as I said befor, that I cannot start off anywhere since I do not know a lot about [hardware] programming in Assembly. I need an OS-Independent protected mode memory manager which is well-comented, so that I can read through every line of it's code to figure out the instructions and how it all works.

Thanks again.

I'm sure the answers to both your questions can be found via the .:QuickLinkz:. thread.

Also:
-- any protected mode memory manager will be OS-dependent, since it will form an integral part of the kernel (or, in the case of a microkernel, it will be a very important server). The memory manager and the OS are inseperable.

-- you don't need to know much assembly to write a kernel. What you do need to know about is general computer architecture. You shouldn't need to be an assembly whiz to understand my tutorials, for instance.

-- to implement file system support, you'll need some kind of disk support first. Floppy I/O is easy, and IDE is only slightly harder. Then you'll need to get hold of a FAT format specification and, basically, follow it.

OK, I found "reference implementation for malloc()" in the QuickLinkz Thread, but the source code is written for win32. Will I be able to use the code if I remove the "windows.h" header!

Thanks again and Sorry that I'm asking so many questions!

You'll need a lot more than just a malloc. Again, please see the memory management tutorials. If you don't understand a particular part, please ask.