Search found 7 matches

by utsav_popli
Tue May 27, 2014 10:14 am
Forum: General Questions
Topic: Running bootloader in qemu
Replies: 0
Views: 16190

Running bootloader in qemu

I have very simple bootloader which i am trying to run through qemu in linux. But qemu gets idle and show "booting from floppy" I dont know how to make it work! I have included bootloader code and makefile script. Here is the code for the bootloader org 0 bits 16 jmp boot1 bootmsg db "...
by utsav_popli
Wed Nov 27, 2013 7:02 am
Forum: General Questions
Topic: Access byte in GDT - chapter 8
Replies: 2
Views: 8116

Re: Access byte in GDT - chapter 8

Ok, Thank You,
Actually tutorial said that since we are not using virtual at this point this bit should be set to 0. Thats y i got confused!!
by utsav_popli
Mon Nov 25, 2013 5:43 am
Forum: General Questions
Topic: Access byte in GDT - chapter 8
Replies: 2
Views: 8116

Access byte in GDT - chapter 8

access bit 7 (bit 47 of descriptor ) says: it should be set to 0 if we are not using virtual mode
But we are setting this bit, why ?

db 10011010b ; access
by utsav_popli
Sun Nov 24, 2013 5:06 am
Forum: Beginners
Topic: replacement for vfd and partcopy on vista x64
Replies: 5
Views: 28736

Re: replacement for vfd and partcopy on vista x64

I am using windows 8 to develop my own OS and I faced so many difficulties: here is what you can do. download vfd for both 64 bit and previous version(32bit) that ran on windows xp. you need to digitally sign vfd drivers. To do so restart ur vista and try pressing F8 AFTER THAT you will get several ...
by utsav_popli
Sun Nov 24, 2013 4:59 am
Forum: Beginners
Topic: problems in tutorial 4
Replies: 2
Views: 9201

Re: problems in tutorial 4

I am not sure, but as far as i found about the bootloader.
bios loads the bootcode at CS:0, ip 07c0
So to make ds and cs point to same are we make ds and other segments 0
by utsav_popli
Sun Nov 24, 2013 4:54 am
Forum: General Questions
Topic: Image file at 0050:0000
Replies: 1
Views: 6782

Re: Image file at 0050:0000

I found out. The answer is unused area in memory area, where we can load our data

http://staff.ustc.edu.cn/~xyfeng/resear ... ne/mem.htm
by utsav_popli
Fri Nov 22, 2013 4:57 am
Forum: General Questions
Topic: Image file at 0050:0000
Replies: 1
Views: 6782

Image file at 0050:0000

Why are we reading the "KRNLD SYS" file at the memory address 0050:0000 ?
Is there any specific reason or just randomly ? or I can load the file anywhere I where I want ?