Loading multiple sectors using int 13h?

[ekanth]

I'm in the process of developing an OS with my friends. I've written the boot code and was able to load a kernel less than 512 bytes. When I tried loading a kernel of size more than 512 bytes the system reboots. I used int 13h with ah = 0x02. When I try to read more than one sector using int 13 it reboots. Could you please help me to write code to load a kernel more than 512 bytes. I would be thankful to you if someone could help me out with a small code snippet(commented please to load a kernel which would span more than one sector. I would also be thankful if you could suggest me a link where I could get some information on this.
Thanks
Sincerely,
Ekanth.

 

[Wody]

Hello,

your example:

;---------------------------- cut here
.MODEL TINY
.CODE
org 0100h

start:
push cs ; Get ES segment for buffer
pop es
mov ax,0203h; Function 2, read sector (3 sectors)
mov bx,offset buffer ; address to buffer
mov cx,1 ; starting from track 0 sector 1
mov dx,0 ; head 0 drive 0 (A)
int 13h ; go
ret ; return to DOS
buffer db 1536 dup(0) ; buffer for 3 sectors

end start
;---------------------------- cut here

If I remember correctly, many BIOS'es won't load something correctly if you try to read something that requires it to switch heads or tracks.
I looked the parameters for the function up in Ralf Brown's interrupt list
Wouter Dijkslag

http://www.wody.demon.nl