Weevil (planned)

[Vik2015]

Finally I started working on my own operating system . I want it to be like MS-DOS except it will not have any graphical apps (only text games ). Currently there is nothing but the VGA driver. Maybe somebody can take a look at the code so I be sure that it contains no errors?

Gitrepo is here https://github.com/Vik2015/weevil/.

P. S. I hope my scrolling function is ok?

[seuti]

Maybe you should have different directories for different platforms, just in case you wanted to expand in the future.

[Roman]

Move your strlen function to a separate file, e.g. string.c

[Vik2015]

Ok, thanks guys. Repo updated

[Roman]

Ok, thanks guys. Repo updated

You should place arch-dependent source files into arch/${ARCH}, arch-independent in the root of src.

[Vik2015]

Ok, thanks guys. Repo updated

You should place arch-dependent source files into arch/${ARCH}, arch-independent in the root of src.

Uhh, not sure what do you mean. Something like this?

Code: Select all

/ #These files are platform-independent. Makefile can be run as `make i686' && `make ...' && ...
  Makefile
  grub.cfg
  # Not sure about those two - they may be platform dependent
  boot.asm
  linker.ld
  i686/
    src/
      kernel.c
      ...
  .../
    src/
      ...

[Nable]

You should place arch-dependent source files into arch/${ARCH}, arch-independent in the root of src.

Topicstarter wants smth like MS-DOS, due to this fact I think that portability and expandable architecture aren't planned at all.

Of course, I should mention this starting point: http://wiki.osdev.org/Beginner_Mistakes .
And one more: http://wiki.osdev.org/Getting_Started .

[Roman]

Ok, thanks guys. Repo updated

You should place arch-dependent source files into arch/${ARCH}, arch-independent in the root of src.

Uhh, not sure what do you mean. Something like this?

Code: Select all

/ #These files are platform-independent. Makefile can be run as `make i686' && `make ...' && ...
  Makefile
  grub.cfg
  # Not sure about those two - they may be platform dependent
  boot.asm
  linker.ld
  i686/
    src/
      kernel.c
      ...
  .../
    src/
      ...

Code: Select all

Makefile
grub.cfg
linker.ld # Can be dependent.
arch/
       /x86
       /...
main.c

All assembly files are arch-dependent, C files can be different, e.g. your VGA driver is arch-dependent, string.c - no.

[Roman]

You should place arch-dependent source files into arch/${ARCH}, arch-independent in the root of src.

Topicstarter wants smth like MS-DOS, due to this fact I think that portability and expandable architecture aren't planned at all.

Of course, I should mention this starting point: http://wiki.osdev.org/Beginner_Mistakes .
And one more: http://wiki.osdev.org/Getting_Started .

His OS is already unlike DOS: written in C, 32-bit and protected.

[BrightLight]

[...] I want it to be like MS-DOS

So it will be a 16-bit DOS-like OS? It's quite odd you're using GRUB for that though.

[Vik2015]

[...] I want it to be like MS-DOS

So it will be a 16-bit DOS-like OS? It's quite odd you're using GRUB for that though.

Well, I didn't want to create my own bootloader (thought I know how - using BIOS calls to read/load sectors, etc.). I am also gonna *try* to write it using only real mode (64kb memory should be enough I guess?) but without using any BIOS calls (or just minimal amount of them).

P. S. It is my first OS dev project after all, don't expect me to be a pro && understand everything

[BrightLight]

Well, I didn't want to create my own bootloader (thought I know how - using BIOS calls to read/load sectors, etc.). I am also gonna *try* to write it using only real mode (64kb memory should be enough I guess?) but without using any BIOS calls (or just minimal amount of them).

You should see this page. It explains on how to switch between 32-bit and 16-bit mode, so you can use BIOS interrupts for disk access. It's also good because your system probably won't be multitasking, seeing it's DOS-like. If you don't want to do this, see Virtual 8086 Mode, which allows you to execute 16-bit code in a 32-bit environment.
For a beginner, the first link is easier to follow.

[iansjack]

Rather than all the kludging with 16-bit and/or Virtual 8086 mode, why not just write a proper disk driver?

[BrightLight]

Rather than all the kludging with 16-bit and/or Virtual 8086 mode, why not just write a proper disk driver?

Because he wants a DOS-like OS, which probably means it would be 16-bit.

[Muazzam]

Rather than all the kludging with 16-bit and/or Virtual 8086 mode, why not just write a proper disk driver?

A single driver is not enough for IDE hard disk, SATA, USB, floppy etc. But a one BIOS interrupt can do that.