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Index > OS Construction > Trying to get hd device information

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MarcoAlves



Joined: 09 Jun 2006
Posts: 30
MarcoAlves
Hi all.

I'd read http://www.geocities.com/siliconvalley/2072/atapi.htm?20062

And I'm trying to get hd device information, but with no success. I'm executing the code under ms-dos (load w98 and restart to ms-dos).

I'd tried so many things and can't make it work.

Please, help-me.

hd.h.asm:
Code:
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; ATA Definitions

; Primary IDE Controller Registers
DATA_REGISTER               equ 0x1F0 ;16 bits wide
ERROR_REGISTER              equ 0x1F1
FEATURES_REGISTER           equ 0x1F1
SECTOR_COUNT_REGISTER       equ 0x1F2
LBA_LOW_REGISTER            equ 0x1F3
LBA_MID_REGISTER            equ 0x1F4
LBA_HIGH_REGISTER           equ 0x1F5
DRIVE_HEAD_REGISTER         equ 0x1F6 ;0x0->master, 0x10->slave
STATUS_REGISTER             equ 0x1F7
COMMAND_REGISTER            equ 0x1F7
ALTERNATE_STATUS_REGISTER   equ 0x3F6
DEVICE_CONTROL_REGISTER     equ 0x3F6

; Status Register
SR_BIT0_ERR     equ 0 ; Error
SR_BIT1_IDX     equ 1 ; Index Mark
SR_BIT2_CORR    equ 2 ; Data Corrected
SR_BIT3_DRQ     equ 3 ; Data Transfer Requested
                      ; 0-> controller has no data for system
                      ; 1-> controller has data for system
SR_BIT4_DSC     equ 4 ; Seek Complete
SR_BIT5_DF      equ 5 ; Device Fault
SR_BIT6_DRDY    equ 6 ; Device Ready
SR_BIT7_BSY     equ 7 ; Busy

; Error Register
ER_BIT0_AMNF    equ 0 ; Address Not Found
ER_BIT1_TK0NF   equ 1 ; Track 0 Not Found
ER_BIT2_ABRT    equ 2 ; Command Aborted
ER_BIT3_MCR     equ 3 ; Media Change Requested
ER_BIT4_IDNF    equ 4 ; ID Mark Not Found
ER_BIT5_MC      equ 5 ; Media Changed
ER_BIT6_UNC     equ 6 ; Uncorrectable Data Error
ER_BIT7_BBK     equ 7 ; Bad Block

; Commands
CMD_IDENTIFY_DEVICE equ 0xEC
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
    


hd.asm:
Code:
ORG 0x100

include 'hd.h.asm'

DT_DEVICE_INFORMATION db 256 dup(?) ; buffer to hold device information

IDE:

;------------------------------------------------------------;
; get device information                                     ;
;------------------------------------------------------------;
.IDENTIFY_DEVICE:
pusha ; save registers
cli ; disable interrupts

;------------------------------------------------------------;
; gets the device information

call .WAIT_WHILE_BUSY
call .WAIT_UNTIL_READY
call .SELECT_PRIMARY_IDE_CONTROLLER

mov dx,COMMAND_REGISTER
mov al,CMD_IDENTIFY_DEVICE
out dx,al

call .WAIT_UNTIL_HAS_DATA
;------------------------------------------------------------;

;------------------------------------------------------------;
; gets the data
mov dx,DATA_REGISTER
mov di,DT_DEVICE_INFORMATION
mov cx,256
cld ;clears direction flag, so insw will increment di
rep insw
;------------------------------------------------------------;

;------------------------------------------------------------;
; process the data
push DT_DEVICE_INFORMATION
pop es
mov bx,DT_DEVICE_INFORMATION
mov cx,256 ; 256 decimal
mov ah,2 ; int 21h, ah=2 escreve um caracter na tela

.loop4:
mov dl,[bx] ; current char to be printed
int 21h
inc bx
loopnz .loop4 ; repeat it 256 times
;------------------------------------------------------------;

sti ; re-enable interrupts
popa ; restore register's original values

mov ah,0x4c  ; ends the program
int 21h

;------------------------------------------------------------;
; loop while ide controller is busy                          ;
; Note that in al,dx is needed because STATUS_REGISTER is    ;
; greater than 8 bits, so, dx is used.                       ;
;------------------------------------------------------------;
.WAIT_WHILE_BUSY:
xor ax,ax
mov dx,STATUS_REGISTER
in al,dx
bt ax,SR_BIT7_BSY
jc .WAIT_WHILE_BUSY

ret

;------------------------------------------------------------;
; loop until ide controller is ready                         ;
; Note that in al,dx is needed because STATUS_REGISTER is    ;
; greater than 8 bits, so, dx is used.                       ;
;------------------------------------------------------------;
.WAIT_UNTIL_READY:
xor ax,ax
mov dx,STATUS_REGISTER
in al,dx
bt ax,SR_BIT6_DRDY
jnc .WAIT_UNTIL_READY

ret

;------------------------------------------------------------;
; loop until ide controller has data for us                  ;
; Note that in al,dx is needed because STATUS_REGISTER is    ;
; greater than 8 bits, so, dx is used.                       ;
;------------------------------------------------------------;
.WAIT_UNTIL_HAS_DATA:
xor ax,ax
mov dx,STATUS_REGISTER
in al,dx
bt ax,SR_BIT3_DRQ
jnc .WAIT_UNTIL_READY

ret

;------------------------------------------------------------;
; Select Primary IDE Controller                              ;
;------------------------------------------------------------;
.SELECT_PRIMARY_IDE_CONTROLLER:
xor ax,ax
mov dx,DRIVE_HEAD_REGISTER
mov al,0x0
out dx,al

ret
    
Post 02 Jul 2006, 15:59
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Mac2004



Joined: 15 Dec 2003
Posts: 313
Mac2004
Hi!

I just took a quick glance of your source. Are you trying define constants hd.h file? Then you should use '=' operator instead of 'equ' operator. Fasm syntax differs eg. from Nasm's syntax.

regards, Mac2004
Post 02 Jul 2006, 19:30
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MarcoAlves



Joined: 09 Jun 2006
Posts: 30
MarcoAlves
Hi. I have this style (equ) in other code and it works fine. I think that, in my code, the hd device information is obtained. I think that the problem is after "; process the data ".

Thx a lot.
Post 03 Jul 2006, 12:15
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zhak



Joined: 12 Apr 2005
Posts: 490
Location: Belarus
zhak
your DT_DEVICE_INFORMATION buffer is too small.
you should reserve 512 bytes. this may be your problem.

i'm confused with this portion of code:
Code:
push DT_DEVICE_INFORMATION
pop es
mov bx,DT_DEVICE_INFORMATION     

what's that? if DT_DEVICE_INFORMATION resides at address 0600h, for example, than you're trying to read address 0600h:0600h instead of 0:0600h (if your buffer is in segment 0h)...
es segment should point to where your data is located. it should not be changed. DT_DEVICE_INFORMATION is an offset. you should use es:DT_DEVICE_INFORMATION, but you're using DT_DEVICE_INFORMATION:DT_DEVICE_INFORMATION address instead. it doesn't point to your buffer at all.
Post 07 Jul 2006, 09:16
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MarcoAlves



Joined: 09 Jun 2006
Posts: 30
MarcoAlves
Hi zhak.

Thx for the help.

Do you know how I can get the SEGMENT of DT_DEVICE_INFORMATION or ANY other label?

Does anyone knows where I can find how a program is loaded into memory (segment, offset, code area, data area, etc, etc)?
I think that this will help me a lot.
Post 07 Jul 2006, 12:02
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zhak



Joined: 12 Apr 2005
Posts: 490
Location: Belarus
zhak
for dos .com applications, when you use the same segment for code and data, the simplest way to get data seg is:

mov ax, cs
mov es, ax
Post 07 Jul 2006, 16:38
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