Testing Under MS VirtualPC 2004

AJ · Post by AJ » Sun Oct 22, 2006 7:12 am

Hello,

Although this is my first post, I have been reading the forums for a bit so thanks for all the help!

I am developping a 'just out of interest' hobby OS which has reached the stage of boot sector, secondary loader and 'dummy' kernel. I normally use Bochs for testing and occasionally boot the "OS" up on real hardware. Both of these seem to work.

On VPC, however, there is a text-mode cursor which appears in the top left of the screen, moves down to the bottom right and simply appears to scroll the screen.

If my OS appears to work under Bochs (displays message, switches to PMode, sets up GDT, paging, interrupts etc....), should I be concerned that it does not appear to function properly under Virtual PC 2004?

Thanks in advance,
Adam

Kemp · Post by **Kemp** » Sun Oct 22, 2006 11:46 am

To my knowledge, Virtual PC focuses its emulation on the things needed for Windows and the rest is more of an aferthought. If both Bochs and real hardware work then I wouldn't be too worried about it.

Touch · Post by **Touch** » Sun Oct 22, 2006 11:56 am

Im running a Linux distro under MVP, and it works fine, slow but fine. And when I was testing my bootloader, it worked correctly. So yeah, you shouldnt have too many problems. Luckily for me, I have a destkop next to my laptop, which I test on!

AJ · Post by AJ » Sun Oct 22, 2006 1:08 pm

Thanks for this.

Although it's only a hobby project, I wanted to iron out any major problems before starting on the kernel proper. I won't lose sleep over it then!

Adam

Touch · Post by **Touch** » Mon Oct 23, 2006 2:05 am

Yeah, before I start a peice of code or testing, I find out what I need to know before I do it.

deathangel · Post by **deathangel** » Tue Oct 24, 2006 10:02 am

If your OS does not work in Virtual PC, there probably is a problem. I have found that 90% of the time my OS code doesn't work in VPC, there really was a bug which Bochs did not pick up. If I put that same floppy on real hardware and it doesn't work on VPC, it will NOT work on the actual thing.

AJ · Post by AJ » Fri Nov 10, 2006 2:57 am

I have an embarrasing confession

My OS effort is now working perfectly under VPC - I think that when I had this problem, I may not have been waiting long enough for the boot loader to do it's work. Since reformatting my (ancient) PC and getting it working more quickly, VPC is now running at a more reasonable pace

Adam