Search found 387 matches

by Andyhhp
Fri Jan 11, 2008 12:08 am
Forum: Advanced OS Development
Topic: Virtulization
Replies: 15
Views: 50474

^_^ - don't worry, i sometimes slip into common habits (I got frustrated after a convo I had with someone went along the lines of: "OMG - I think someone is hacking my computer! You sure? Defiantly - there must be a hacker at another computer trying to hack me over the internet! Even though your not...
by Andyhhp
Thu Jan 10, 2008 12:40 pm
Forum: Advanced OS Development
Topic: Virtulization
Replies: 15
Views: 50474

From what you want about pointers and base class permissions, it would make sense to write a custom programming language that has that attributes. You might even be able to vastly reduce the workload that your interpreter has to do if it knows that the program was written in your language. But how p...
by Andyhhp
Wed Jan 09, 2008 12:46 pm
Forum: Advanced OS Development
Topic: Virtulization
Replies: 15
Views: 50474

Good Question - That is certainly an interesting idea. However, I am not sure how feasible it is. It is certainly possible to make an interpreter although to make a good one is very hard. As for speed, most programs can be made faster by improving algorithms, and using trickery (bit operations, loop...
by Andyhhp
Wed Jan 09, 2008 12:18 pm
Forum: Assembly Language
Topic: Entering 32bit (un)real mode
Replies: 3
Views: 18381

I dont think so. From what I understand, unreal mode is exactly the same as real mode except for the fact that it uses Pmode addressing so that if you set up the GDT correctly, you can access all memory. Therefore, you should be able to use all the BIOS interupts, in the same way as you did in your ...
by Andyhhp
Fri Jan 04, 2008 9:14 pm
Forum: Assembly Language
Topic: Entering 32bit (un)real mode
Replies: 3
Views: 18381

As far as I am aware (and I might be totally wrong), to enter unreal mode, you have to enable the A20 line, enter Pmode, load the GDT so you can access all of memory, then switch back into Realmode. This should allow you to use realmode except that it uses Pmode addressing, which allows you all memo...
by Andyhhp
Tue Jan 01, 2008 12:28 am
Forum: Advanced OS Development
Topic: Pure multithreading/multicore processors?
Replies: 3
Views: 19789

The CPUID instruction can be used to find out how many cores are present. You will have to find the documentation relevent to the processor you are writing your code for because the CPUID instruction is vender-dependant. As for running programs on different cores, first you have to start them (as on...
by Andyhhp
Tue Jan 01, 2008 12:23 am
Forum: Assembly Language
Topic: Floating point variables and Math?..
Replies: 1
Views: 13148

most definatly In the CPU, along with the ALU, there is the FPU which deals entirely with floating point numbers. all floating point instructions begin with an 'f' so that add would be 'fadd'. However, using the FPU is harder than normal. There are 8 80bit registers that work similar to a stack. 32 ...
by Andyhhp
Sat Dec 22, 2007 11:27 pm
Forum: Advanced OS Development
Topic: compatibility
Replies: 1
Views: 15309

Some of the tutorials said that loading a program from a PE file would be covered. As far as I am aware, this is standing(or at least supported) to become standard between the different major OS's As for other data, all you really need is an ability to export the data into other formats (e.g. JPEG, ...
by Andyhhp
Fri Dec 21, 2007 4:18 pm
Forum: Beginning OS Development
Topic: puts() using asm
Replies: 1
Views: 6629

Firstly, to print strings, the function should be declared as 'unsigned char *' else it will only work for a single character. Also, there are a few problems with your ASM code: 1)you need a jump at the beginning of the block to prevent the program trying to execute data (A good compiler should catc...
by Andyhhp
Wed Dec 12, 2007 11:00 pm
Forum: Article Feedback
Topic: Error with LBA to CHS conversion
Replies: 2
Views: 17595

Having read both of the new tutorials, ive noticed that the same error occurs when you are rewriting the FAT12 driver for the second stage. I assume this is for the same reason :wink:
by Andyhhp
Sun Dec 09, 2007 11:03 pm
Forum: Article Feedback
Topic: Error with LBA to CHS conversion
Replies: 2
Views: 17595

Error with LBA to CHS conversion

Im sorry to moan but I hope you dont mind having errors pointed out :oops: in the OS series, in http://www.brokenthorn.com/Resources/OSDev6.html , and in the comments in the downloadable source code, the following is written about converting an LBA address to a CHS one: absolute sector = (logical se...
by Andyhhp
Fri Oct 26, 2007 10:52 am
Forum: Article Feedback
Topic: Query about FAT12 format
Replies: 1
Views: 13471

Query about FAT12 format

Hi, In your tutorial OSDev5.html, about half way down, when describing the two bpb values 'bpbReservedSectors and bpbNumberOfFATs', you make the comment bpbNumberOfFATs rpresents the number of File Allocation Tables (FATs) on the disk. The FAT12 File System always has 2, 1 in the second sector, and ...