Booting

[neowert]

So I wrote a bootloader and basic OS. Then I stopped coding for a while due to lazyness. I want to get back into kernel coding, but there are a few things I want to do differently. I got nasm to compile on my OS X (mac) machine. I plan on developing with that, while running the OS on my x86 box. Anyway, is there a bootloader I could I could put on a floppy that would boot an image from my mac via a network connection? I do not have the money or tools to put a bootrom chip on my NIC, otherwise I would do that.

[Tim]

GRUB will do that for you.

[neowert]

Can DOS do TCP/IP? When DOS was still popular, I was not programming, so I have done limited coding for it. It would be easy enough to write myself. DOS can write anywhere in RAM right?

[Schol-R-LEA]

Can DOS do TCP/IP? When DOS was still popular, I was not programming, so I have done limited coding for it. It would be easy enough to write myself.

The last standalone version of MS-DOS didn't support TCP/IP directly. TCP/IP stacks did exist for it, but never worked very well; the internet protocols really need a preemptively multitasking system to work properly. Also, I'm pretty sure that they all used DPMI or some other protected mode extension, primarily for the extra memory space. I don't know what IBM has done with PC-DOS, nor do I know what FreeDOS supports, but I'd be surprised if either of them had extended the networking support substantially. I do know that there is a version of Arachne for FreeDOS though, so it must have some ability to run TCP/IP.

DOS can write anywhere in RAM right?

In principle, any OS should be able to write to any part of memory that is not mapped to something read-only. Whether it will let the user do so is another matter. While MS-DOS doesn't restrict you too much, it runs in real mode, which means you'd only be able to address the lower 1MB + 48KB of memory.