Search found 92 matches

by halofreak1990
Sun Feb 27, 2011 12:08 pm
Forum: Beginning OS Development
Topic: How to read input from user into a double-type variable
Replies: 3
Views: 5457

Re: How to read input from user into a double-type variable

The easiest way to get what you want would be to search online for an implementation of strtod (string to double) it's somewhere in the C library. I've heard the Microsoft C library source code is supplied with each Visual C++ compiler, so you could take a look at it. As long as it's written in plai...
by halofreak1990
Thu Feb 24, 2011 8:33 pm
Forum: General Programming
Topic: Kernel trouble
Replies: 19
Views: 34744

Re: Kernel trouble

<EDIT> I've moved the HAL init to the very first thing after the kernel entry sets up the segment registers. Now, instead of crashing due to exceptions being thrown that aren't handled because the IDT and Exception handlers weren't in place, Bochs just hangs. It clears my screen to blue, like it sho...
by halofreak1990
Wed Feb 23, 2011 9:26 pm
Forum: General Programming
Topic: Kernel trouble
Replies: 19
Views: 34744

Re: Kernel trouble

Because your post mentioned that these issues just started occurring lately, I assume that your bootloader has worked fine in the past? Yes, it did. Were there any modifications to the bootloader software? Please do note that the bootloader provided by the series was not designed for kernels that e...
by halofreak1990
Tue Feb 22, 2011 8:49 pm
Forum: General Programming
Topic: Kernel trouble
Replies: 19
Views: 34744

Re: Kernel trouble

...so from here you need to debug your IDT and find out why its double faulting in the first place. Now there's a problem, the IDT isn't set up until the kernel registers its interrupt handlers, which it can't get to because of the errors taking the system down. As it crashes when the 2nd stage jum...
by halofreak1990
Fri Feb 18, 2011 1:52 pm
Forum: Beginners
Topic: confusion on multiple initialization of GDT
Replies: 3
Views: 10947

Re: confusion on multiple initialization of GDT

The GDT in the bootloader was a generic one to make sure we could properly go to protected mode, but it lacked specifics, I.E. privileges and protection, which is fixed by the one created in the kernel. and from this i have got that we can set up new gdt and invalidate the old whenever required? is ...
by halofreak1990
Fri Feb 11, 2011 12:25 am
Forum: Beginning OS Development
Topic: Bitwise Operations in Physical Memory Manager
Replies: 5
Views: 7287

Re: Bitwise Operations in Physical Memory Manager

Am I right in saying that array indexes/values are still linear in memory it is just the values that are read right to left? map[0] map[1] 0000 0000 0000 0000 0000 0000 0000 0000 ... 0000 0000 0000 0000 0000 0010 0000 0000 The bit set as 1 there is the 42nd bit in the memory map that represents the...
by halofreak1990
Thu Feb 10, 2011 1:03 pm
Forum: Beginning OS Development
Topic: Bitwise Operations in Physical Memory Manager
Replies: 5
Views: 7287

Re: Bitwise Operations in Physical Memory Manager

Bits are read from right to left like this:

Code: Select all

bit 31                                       bit 0
      0000 0000 1000 0000 0000 0000 0000 0000
which would make the set bit bit 23
by halofreak1990
Wed Feb 09, 2011 8:50 pm
Forum: General Programming
Topic: Kernel trouble
Replies: 19
Views: 34744

Kernel trouble

Lately, I've been having trouble with triple-faulting when the bootloader jumps to my kernel. Since real hardware doesn't give any info on its registers, I installed Bochs and ran my kernel again. These are the results: Booting from 0000:7c00 interrupt(): gate descriptor is not valid sys seg (vector...
by halofreak1990
Sat Feb 05, 2011 9:23 pm
Forum: General Programming
Topic: OS Development Series code question
Replies: 34
Views: 57946

Re: OS Development Series code question

In response to a previous post of mine: Also, I noticed the kernel is loaded at RealMode address 0x3000, and the stack at 0x9000. Now, a bit of calculating tells me there's roughly 24 KB between those two points in memory. You told me the stack grows downwards... which means that, with my kernel bei...
by halofreak1990
Tue Jan 11, 2011 4:42 pm
Forum: Beginners
Topic: NASM
Replies: 3
Views: 10633

Re: NASM

It seems like NASM cannot find the file to compile. Are you sure the file Boot1.asm exists?
Otherwise, if your file is boot1.asm, just change the first letter into a capital B, and it should find it, provided the file is located in the same directory as NASM.
by halofreak1990
Tue Jan 11, 2011 4:39 pm
Forum: News Discussion
Topic: PE Chapter released
Replies: 5
Views: 33992

Re: PE Chapter released

Happy new year to you too, and thx for the update.
by halofreak1990
Sat Jan 08, 2011 2:18 pm
Forum: Assembly Language
Topic: doubt on int 10(0e) & reading sector
Replies: 4
Views: 11861

Re: doubt on int 10(0e) & reading sector

hello guys i have few doubts from int 10 and reading sector from usb i)int 10h int 10 AH = 0E AL = ASCII character to write BH = page number (text modes) BL = foreground pixel color (graphics modes) As you can see what is page number(in BH register) and what do they exactly mean by graphics mode(BL...
by halofreak1990
Wed Jan 05, 2011 7:27 pm
Forum: Beginners
Topic: simple question
Replies: 3
Views: 11281

Re: simple question

You can, but you'll have to make drastic changes to the bootloader to get the bootsector to work. (must be 2048 bytes, last two bytes must be the boot signature 'AA55' etc.) And, of course, you'll need some software to actually write your bootloader to the bootsector of a virtual disc image. I did t...
by halofreak1990
Thu Dec 30, 2010 3:58 pm
Forum: Advanced OS Development
Topic: Virtual Memory problems in VMWare player
Replies: 4
Views: 10395

Re: Virtual Memory problems in VMWare player

Thanks. I'll try that. And sometimes under some optimization levels, kernel memory corruptions occur. I can't understand why those things happen. And VM mapping in Mikes tute is not clear Identity map 1st 4mb Map 3gb to 1mb This way, two pages map to same physical addr. Isn't this a problem? No, it...
by halofreak1990
Thu Dec 30, 2010 2:07 pm
Forum: Advanced OS Development
Topic: Virtual Memory problems in VMWare player
Replies: 4
Views: 10395

Re: Virtual Memory problems in VMWare player

I have a similar problem as you do. Initializing the Virtual Memory Manager triple faults real and virtual hardware. I think I'm gonna revert my VMM to before I started to integrate the User Mode stuff, because that's when it started to fail. Another thing I found odd, was after a couple of changes ...