Bona Fide OS Developer
View unanswered posts | View active topics It is currently Sun Dec 16, 2018 11:41 pm



Post new topic Reply to topic  [ 8 posts ] 
 int 0x13 extension 
Author Message

Joined: Sat Sep 26, 2009 4:29 am
Posts: 15
Location: Philippines
Post int 0x13 extension
My OS development stopped for months because I'm stuck w/ my bootloader(I can't figure out why...maybe I'm just too dumb for this stuff :-( )...and I'm busy w/ other things... Here's my progress..

Code:
bits    16

jmp short boot
nop
SystemVersion      db "SAIDOS  "
BytesPerSector      dw 0x200
SectorsPerCluster   db 2
ReservedSector      dw 3
FATCount         db 2
RootDirCount      dw 0x20
SectorCount16      dw 19728 ;19728 19642 for data(9821 cluster)
MediaDescriptor      db 0xF8
SectorsPerFAT      dw 40    ; 10240 clusters
SectorsPerTrack      dw 63
HeadCount         dw 1
HiddenSectorCount   dd 0
SectorCount32      dd 0

;FAT16
Drive            db 0x80
FlagNT            db 0
Signature         db 0x29
SerialNumber      dd 0x01020304
VolumeLabel         db "NO NAME    "
SystemID         db "FAT16   "

; VARIABLE
bootx   equ 0x7c00
datax   equ 0x7b00
drv      equ datax; byte

;DAP
dap:
db 0x10
db 0
dap_count db 0
db 0
dap_bfr dd 0
dap_lba dq 0


boot:
cli
xor ax,ax
mov ds,ax
mov ss,ax
mov es,ax
mov sp,0xFFFF

mov [drv],dl      ; Save the drive number which it has booted from

mov si,bootx+msg_load
call sys_print

; check if int 0x13 ext is present
mov ah,0x41
mov bx,0x55aa
int 0x13

jnc int13extok
mov si,bootx+msg_noint13ext
call sys_print
jmp $

int13extok:
mov si,bootx+msg_load2
call sys_print

mov ah,0x42
mov dl,[drv]
mov si,bootx+dap
mov byte[bootx+dap_count],1
mov dword[bootx+dap_bfr],0x00007e00
mov dword[bootx+dap_lba],0x0002
mov dword[bootx+dap_lba+4],0x0000
int 0x13

mov si,bootx+0x200
call sys_print

jmp $

sys_print:
;si - msg address
push ax
mov   ah,0x0e      ;display char and advance cursor
printx:
cmp byte[si],0   ;is byte[si] == 0?
je   printx_exit   ;if TRUE terminate loop
mov al,[si]      ;display byte[si]
int 0x10      ;
inc si         ;move to next character
jmp printx      ;loop
printx_exit:   ;
pop ax
ret

sys_read:
ret

; DATA
msg_load db "Sajia BOOTLOADER",0x0a,0x0d,0
msg_noint13ext db "ERROR: int 0x13 extension not available",0x0a,0x0d,0
msg_load2 db "[LOADING]",0x0a,0x0d,0

times 510 -($-$$) db 0   ;
dw 0xAA55      ;boot signature
next:
;
;
;
sample db "HAHAHAHAHAHAHAHAHAHAHA",0

times 1024 -($-$$) db 0   ;


this should display:

Sajia BOOTLOADER
[LOADING]
HAHAHAHAHAHAHAHAHAHAHA

but I guess the code for loading sectors is not working (I'm using int 0x13 extension..does this feature works only in phoenix bios??)... I'm using bochs...


Last edited by prinzrainer on Sun Jan 24, 2010 1:49 am, edited 1 time in total.



Sat Jan 23, 2010 3:41 am
Profile

Joined: Tue Jan 19, 2010 11:51 pm
Posts: 66
Post Re: int 0x13 extension
Umm... I didn't look closely, but it looks like you are setting all your segment registers to zero. You definitely don't want that, I think.

Edit: Nevermind, I just saw the 0x7c00 value. I donno, off hand. Just keep trying stuff until it works. That's the secret. Persistance. Eventually, you will be doing stuff with no one to help. All you can do is try different things, even crazy things, and get clues.


Sat Jan 23, 2010 5:39 am
Profile

Joined: Thu Jan 07, 2010 4:46 am
Posts: 5
Post Re: int 0x13 extension
The extensions don't work on a floppy disk (I guess, you're using an FDD). You have to use the old CHS way there.

And, btw, there's an "org" command which is capable of relocating all your code. Just use "org 0x7C00" before everything and this value will be added to all your labels. ;)


Sat Jan 23, 2010 5:58 pm
Profile

Joined: Sat Sep 26, 2009 4:29 am
Posts: 15
Location: Philippines
Post Re: int 0x13 extension
i'm using it in HD ( you can't have fat16 in FD )...yeah....i have a mistake in the code it is supposed to be
Code:
mov ah,0x42
mov dl,[drv]
mov si,bootx+dap
mov byte[bootx+dap_count],1
mov dword[bootx+dap_bfr],0x00007e00
mov dword[bootx+dap_lba],0x0002
mov dword[bootx+dap_lba+4],0x0000
int 0x13

rather than
Code:
mov ah,0x42
mov dl,[drv]
mov si,bootx+dap
mov byte[dap_count],1
mov dword[dap_bfr],0x00007e00
mov dword[dap_lba],0x0002
mov dword[dap_lba+4],0x0000
int 0x13


but still, there's an error...btw if I'll use PIO how can I know the port addresses of the drives?? suppose...the drive where the program booted is 80...how can I know it's port address (w/o using the int 0x13 fn 0x48 Extended Read Drive Parameters )??

you can add me in facebook,,mynameisrainer@yahoo.com...I really need help...


Last edited by prinzrainer on Wed Jan 27, 2010 11:01 pm, edited 1 time in total.



Sun Jan 24, 2010 1:48 am
Profile

Joined: Thu Jan 07, 2010 4:46 am
Posts: 5
Post Re: int 0x13 extension
prinzrainer wrote:
i'm using it in HD ( you can't have fat16 in FD )

Ah, sorry, missed that.

I really suggest you to use org. It's very hard to calculate all the addresses correctly in the way you do.

prinzrainer wrote:
btw if I'll use PIO how can I know the port addresses of the drives?? suppose...the drive where the program booted is 80...how can I know it's port address (w/o using the int 0x13 fn 0x48 Extended Read Drive Parameters )??

Base port address for the first ATA drive is 0x1F0. For more information read that article (for example): http://wiki.osdev.org/IDE


Mon Jan 25, 2010 11:18 am
Profile

Joined: Sat Sep 26, 2009 4:29 am
Posts: 15
Location: Philippines
Post Re: int 0x13 extension
solved it!! I did same mistake again....sector number start from 0....


Wed Jan 27, 2010 11:15 pm
Profile

Joined: Sat Jul 25, 2009 11:26 am
Posts: 81
Post Re: int 0x13 extension
The first sector is sector no. 1. Your code is full of non-sense packed in a packed in a 1024-byte sector instead of 512. ;)


Sun Feb 21, 2010 9:51 pm
Profile

Joined: Sat Sep 26, 2009 4:29 am
Posts: 15
Location: Philippines
Post Re: int 0x13 extension
i mean lba... it's a 512-byte sector though the file size 1024 bytes.. i use hex workshop to copy it to a disk image file...


Sun Feb 21, 2010 11:45 pm
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 8 posts ] 


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group.
Designed by Vjacheslav Trushkin and tweaked by the BF Team.