What's 64 Bit Like?

[Lprogster]

I'm interested about 64 bit OSs. Are there any tutorials for them - I can't find any on Google or the wiki? How easy is it to port an OS to 64 bits? Does GRUB support 64 bit loading?

Also, out of interest, how many of you have 64 bit OSs?

Cheers,
Lster

[13postures]

I'm in the process of implementing a 64-bit kernel so i can answer a few questions.

I'm interested about 64 bit OSs. Are there any tutorials for them - I can't find any on Google or the wiki?

You mustn't have looked very well. Try this for starters: http://en.wikipedia.org/wiki/64_bit

You should also understand that there is not only one kind of 64-bit architecture. Consult the above link.

How easy is it to port an OS to 64 bits? Does GRUB support 64 bit loading?

Well, at first it might seem easy to make such a port but it needs a lot of work. The first thing you have to do is modify your kernel's data types as fit. The most important thing here is the pointers. Pointers are 32-bits in size on a 32-bit os, but they are 64-bits on a 64-bit os. Check this out: http://www.unix.org/whitepapers/64bit.html. After modifying your data types, you have to create an appropriate pmap module and many many other stuff.

GRUB does not support loading elf64 images.

Also, out of interest, how many of you have 64 bit OSs?

Debian/amd64 here.

[os64dev]

I am also writing a 64-bit OS and indeed there aren't many tutorials around. I got all the information from both the Intel and AMD manuals and of course for osdev.org. First thing build a cross-compiler and build bochs with amd64 support and skip grub or other boot loaders. Build your own bootloader. From that point onwards 64-bit is not much different then 32-bit only how the lowlevel stuff like interrupts are handled, etc.

[Candy]

I'm interested about 64 bit OSs. Are there any tutorials for them - I can't find any on Google or the wiki? How easy is it to port an OS to 64 bits? Does GRUB support 64 bit loading?

Also, out of interest, how many of you have 64 bit OSs?

Cheers,
Lster

*check* -> 64-bit bootcode and an attempt at an OS. Problem is that the bootloader decompresses the kernel wrongly so the 64-bit kernel doesn't work at the moment. Have been working it but overtime at work hinders progress. I expect to have it working (...) again by friday.