Search found 436 matches

by Mike
Wed Apr 06, 2011 11:34 pm
Forum: Advanced OS Development
Topic: Can we use OpenGL in protected mode ?
Replies: 3
Views: 10164

Re: Can we use OpenGL in protected mode ?

Hello, The following are the only good free resources that I am aware of: FreeVGA OSDev Wiki In addition, there are books that cover VGA in depth. Please note the VGAs limitations; OpenGL is typically used with SVGA+ resolutions which VGA does not support. VGA is limited to 640x480x16 color; anythin...
by Mike
Sat Apr 02, 2011 6:21 pm
Forum: General Programming
Topic: Kernel trouble
Replies: 19
Views: 34000

Re: Kernel trouble

Hello, There is a potential bug with regards to the when kernelSize was being initialized. It has been fixed for the Chapter 24 release. kernelSize should be set in kernelEntry because it is obtained from DX which might get trashed. A better method is to have the kernel obtain its own size directly ...
by Mike
Sun Mar 27, 2011 8:49 pm
Forum: Beginning OS Development
Topic: Paging doesn't enable despite calling ..._enable(true);
Replies: 1
Views: 4313

Re: Paging doesn't enable despite calling ..._enable(true);

Hello, That might indicate a bug in the software and will be looked into with Chapter 24's release. pmmngr_is_paging determines if paging is enabled using the PG bit of CR0. Because of this, its not related to any PMM routines. Please note pmmngr_paging_enable has very few cases where it can be usef...
by Mike
Mon Mar 14, 2011 9:36 pm
Forum: General Programming
Topic: Kernel trouble
Replies: 19
Views: 34000

Re: Kernel trouble

Hello, I find it suspicious that the latest chapter would work considering it does not contain the updated VMM software. The PMM is the same in both demos so I suspect it might be this update that causes the compatibility issue with your PC. Please verify if this assumption is correct by comparing t...
by Mike
Mon Mar 14, 2011 5:06 am
Forum: General Questions
Topic: The ImageSig
Replies: 4
Views: 14951

Re: The ImageSig

Hello, Our in-house bootloader can load and execute flat binaries that are multiboot compliant. An example from the bootloader will not help however. What I personally recommend is to try it yourself first: Decide on a standard to use and the goals for the bootloader and kernel relationship, if any....
by Mike
Mon Mar 07, 2011 4:40 pm
Forum: Beginning OS Development
Topic: Reading from disk troubles (demo 22)
Replies: 3
Views: 5452

Re: Reading from disk troubles (demo 22)

Hello,

The original post did not imply a copy+paste so please do not concern with that. The terminology used in my reply ("your version of the OS") was used only to reflect the terminology you used in your original post ("my version of your OS") and nothing more.
by Mike
Mon Mar 07, 2011 4:28 pm
Forum: General Programming
Topic: Kernel trouble
Replies: 19
Views: 34000

Re: Kernel trouble

Hello, The triple fault is caused by a page fault exception at e001fea6. Knowing that this results in a gpf implies that you might have corruption (invalid IDT or exceptions). Knowing that those issues begun recently implies that your IDT code itself must be fine if it has been used in the past. The...
by Mike
Mon Mar 07, 2011 4:02 pm
Forum: General Questions
Topic: The ImageSig
Replies: 4
Views: 14951

Re: The ImageSig

Hello, The signature is specific to PE executables. If you would like to use a PE executable written in assembly language or C the signature must match. If you want to use a custom image format or a non-PE image then it is indeed not required. The boot loader was designed to parse PE executables so ...
by Mike
Sun Feb 27, 2011 12:28 am
Forum: General Questions
Topic: Chapters
Replies: 12
Views: 26712

Re: Chapters

Hello, Chapter 24 (Loaders) is planned for release in about two weeks. Currently there is no ETA on the second chapter to cover graphics due to no currently decided direction. A chapter covering the VESA VBE will probably be next to help ease the transition into VGA and SVGA. If it becomes official,...
by Mike
Wed Feb 23, 2011 7:38 pm
Forum: General Programming
Topic: Kernel trouble
Replies: 19
Views: 34000

Re: Kernel trouble

Hello, Because your post mentioned that these issues just started occurring lately, I assume that your bootloader has worked fine in the past? Were there any modifications to the bootloader software? Please do note that the bootloader provided by the series was not designed for kernels that exceed 6...
by Mike
Thu Feb 17, 2011 6:33 pm
Forum: Beginning OS Development
Topic: Reading from disk troubles (demo 22)
Replies: 3
Views: 5452

Re: Reading from disk troubles (demo 22)

Hello, Does "Your version of the OS" not have issues with opening a file? What are the differences between "your version" and the OS provided by the series? The series OS uses a structure to store function pointers to filesystem specific routines. _FileSystems[device - 'a'] shoul...
by Mike
Sat Feb 12, 2011 6:12 pm
Forum: Beginning OS Development
Topic: Using a Hard Disk (or image) instead of floppy?
Replies: 2
Views: 8781

Re: Using a Hard Disk (or image) instead of floppy?

Hello, You will need to write support for ATA (probably serial ATA) in order for the software to read and write from the hard disk. Serial ATA is fairly complicated however you can find some example code online including the specification. Because most hard disks are not formatted with FAT12 (if any...
by Mike
Thu Feb 10, 2011 7:19 pm
Forum: Beginning OS Development
Topic: Bitwise Operations in Physical Memory Manager
Replies: 5
Views: 7143

Re: Bitwise Operations in Physical Memory Manager

Hello, "memory is linear from left to right" isnt entirely accurate. In little endian systems, a dword value like 0x0a0b0c0d is stored as 0d 0c 0b 0a in memory. Notice how the dword is completely backward when stored in memory. This fact can be verified using C byte pointers to access an i...
by Mike
Thu Feb 10, 2011 2:55 am
Forum: Beginning OS Development
Topic: Problem with bootloader
Replies: 8
Views: 9500

Re: Problem with bootloader

Hello, You really need to start providing information - this has been requested three times (now four). What debugging steps have you already performed? If none, why not? Does the file ever get found? How do you assemble and copy the programs to disk? Your bochs crash log (if using bochs) can also h...
by Mike
Wed Feb 09, 2011 7:40 pm
Forum: Beginning OS Development
Topic: Problem with bootloader
Replies: 8
Views: 9500

Re: Problem with bootloader

Hello, Please add the bpbOEMName change as noted above. In addition replace start: jmp main with the following: start: jmp short main nop Newer versions of NASM will assemble this instruction differently, which can cause the BPB to start at a wrong offset. The above fixes this. filename db "KRN...