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Loading multiple sectors using int 13h?

Loading multiple sectors using int 13h?

Loading multiple sectors using int 13h?

(OP)
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.

RE: Loading multiple sectors using int 13h?

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
 

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