BrokenThorn Entertainment

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...

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...

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...

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....

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 ...

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...

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...

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 ...

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...

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...

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...

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.)

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...

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...

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...