Search found 436 matches

by Mike
Sat Aug 10, 2019 2:16 am
Forum: Beginning OS Development
Topic: int 0x13, AH 0x02
Replies: 3
Views: 1057

Re: int 0x13, AH 0x02

Hi, ES:BX is used as the location to where the sector is loaded into. If BX wraps back around from 0xfe00 to 0 (keep in mind BX is incremented by 0x200 bytes each time we read a sector), CF gets set if BX overflows. This tells us that ES:BX has reached the end of its segment. Since real mode segment...
by Mike
Sat Jun 01, 2019 3:01 am
Forum: Beginning OS Development
Topic: int 0x13, AH 0x02
Replies: 3
Views: 1057

Re: int 0x13, AH 0x02

Hi, There is a known error in the original implementation of readSectors where BX may overflow. The following modifications will resolve it: ReadSectors: ; ; go to following instruction in your code: ; add bx, WORD [bpbBytesPerSector] ; ; ...and use the below code right after above instruction: ; jn...
by Mike
Wed May 03, 2017 2:21 am
Forum: Advanced OS Development
Topic: Can anyone help me put better sound in my OS
Replies: 1
Views: 4850

Re: Can anyone help me put better sound in my OS

Hello, Many audio devices support the AC'97 and Intel's High Definition Audio (HDA) standards. The AC'97 specification can be found here . The Intel HDA specification can be found here . The OSDev.org Wiki also provides an overview on both of them ( AC'97 , HDA .) Of course, if the device does not s...
by Mike
Sat Apr 22, 2017 3:35 am
Forum: Article Feedback
Topic: Cant we help improve our forum
Replies: 2
Views: 4639

Re: Cant we help improve our forum

Hello, We are actually currently planning a new version and re-release of the OS Development Series and eventual rewrite of the entire site. Due to time constraints, we will probably end up integrating the existing forum into the site for now until more time is available for working on the new site....
by Mike
Sat Jun 04, 2016 9:51 pm
Forum: General Questions
Topic: Executing binary with demo 25
Replies: 1
Views: 8422

Re: Executing binary with demo 25

Hello, We provided PE loading support in Chapter 24 for demonstration purposes only. As you are aware, we removed it in Chapter 25 so we can demonstrate threading and multi-threading without the overhead of supporting user mode processes. Supporting user mode processes is still possible, however to ...
by Mike
Tue Jan 26, 2016 7:09 am
Forum: News Discussion
Topic: Chapter 25: Process Management 2
Replies: 5
Views: 30924

Re: Chapter 25: Process Management 2

Hello everyone, The initial release of the Chapter 25 demo software and some additional updates to the text was released. It contains about a thousand lines of new code since the process loading code was rewritten for the threading support. Thank you for the suggestions for supporting UEFI. We do pl...
by Mike
Wed Jan 20, 2016 12:48 am
Forum: News Discussion
Topic: Chapter 25: Process Management 2
Replies: 5
Views: 30924

Re: Chapter 25: Process Management 2

Hello everyone. Thanks for the feedback and suggestions. We will most probably be going with the memory management topics given that we had to make some additional changes in the demo to accommodate for the lack of proper address space management and heap allocator. The next chapter have been starte...
by Mike
Wed Jan 06, 2016 2:52 am
Forum: News Discussion
Topic: Chapter 25: Process Management 2
Replies: 5
Views: 30924

Chapter 25: Process Management 2

Hello everyone, The initial release of the OS Development Series Chapter 25 is out. The chapter primary covers concurrent programming, scheduling, and multitasking. Other topics include IPC, Process state management, and a brief introduction to SMP. The Chapter 25 demo program should be released in ...
by Mike
Fri Nov 20, 2015 2:41 am
Forum: News Discussion
Topic: Updates
Replies: 1
Views: 13159

Updates

Hello everyone, We are currently in the process of integrating the forum software into the site and updating it. There may be a few errors, however most of the problems appear to have been resolved. Please report any issues with the administrators and we apologize for the inconvenience. We will be p...
by Mike
Sun Mar 02, 2014 11:08 pm
Forum: Beginning OS Development
Topic: MS VPC Issue
Replies: 8
Views: 12041

Re: MS VPC Issue

Hello, Yes, the series is still continuing. A couple of chapters are being worked on; particularly Graphics 3 and Process Management 2. Unfortunately due to a lack of time, we have not been able to push out these articles yet. In the worst case, they will be out a little later this year. If interest...
by Mike
Wed Jan 08, 2014 10:57 pm
Forum: Beginning OS Development
Topic: MS VPC Issue
Replies: 8
Views: 12041

Re: MS VPC Issue

Hello, Apologies for the late response. Be careful with preserving the registers as the BIOS makes no guarantees. Make sure to push/pop DI in order to preserve the counter. Additionally, add additional error checking: make sure that the disk gets reset without error. Note that the disk reset BIOS se...
by Mike
Wed May 08, 2013 10:09 pm
Forum: Beginning OS Development
Topic: IDT installing help
Replies: 2
Views: 8804

Re: IDT installing help

Hello,

Technically no but recommended. Most of the exceptions indicate errors triggered by the current process and should be handled properly. (We emphasize most; other exceptions are used for debugging and system management, i.e. page faults.)
by Mike
Mon Apr 22, 2013 11:47 pm
Forum: News Discussion
Topic: Chapter 24 Initial Demo Release
Replies: 1
Views: 22663

Chapter 24 Initial Demo Release

Hello everyone, Apologies for the delaying of the demo release that was initially planned some time ago. This is an initial release for the chapter 24 demo. The software implements a basic single tasking operating system; supporting executing user mode 32 bit PE images in separate address spaces. Ch...
by Mike
Sun Mar 10, 2013 10:07 pm
Forum: News Discussion
Topic: OSDev Series: Graphics 2
Replies: 1
Views: 20362

OSDev Series: Graphics 2

Hello everyone, This is the initial release for the OSDev Series Graphics 2 article which covers the interfaces between system software and video hardware. Topics include VGA firmware, introduction to VGA hardware programming, SuperVGA, VBE, and accessing display memory. This provides the basic fram...
by Mike
Sun Mar 10, 2013 9:51 pm
Forum: News Discussion
Topic: Chapter 24: Process Management Initial Release
Replies: 16
Views: 94744

Re: Chapter 24: Process Management Initial Release

Hello everyone, Just a quick update... the demo software is functionally completed but not yet cleaned up and stress tested. If no problems occur, it is planned for release this weekend with some additional updates to the article and some additional content. The software implements single-threaded u...