A weird ATAPI problem

[pradeep]

I made a routine to eject the cd.
@Bochs: At first time the cd is ejecting properly. Then it doesn't ejects.
@VMWare: The CD is not at all ejected.
@Real Hardware: The CD is not ejected for the first time. Then it always ejects properly.
Why is this weirdness? Is this becoz of poor coding or improper configuration or anything else.
One thing i forgot to say. Everytime the IRQ fires properly in all the three cases.

In VMware how could i see the configurations like ioaddr1 & 2 as in case of Bochs.

config
------
ata1: enabled=1, ioaddr1=0x170, ioaddr2=0x370, irq=15
ata1-master: type=cdrom, path=F:, status=inserted

[Exabyte256]

Maybe you're trying to send a command to the device when
it doesn't feel like listening?

Before sending the packet, try checking the status register for the busy flag to be off, and for the device ready flag to be on. (0x177).

Here's the only code example on the net of ATA/ATAPI that I can actually understand. Scroll down to the ATAPI example, which happens to be an eject command.
http://www.geocities.com/SiliconValley/2072/atapi.htm

[Dex4u]

I have about 20 test pc, and my atapi driver works on all of them, but one pc, you need to press the keyboard two times to get the cd to open, the first time it does not work, but them it works find after the second press and it only does that on that pc, on the first press of a reboot.
So its down to the CD on the pc, you will find it works fine on another pc.
I would not worry about it.

[pradeep]

@Exabyte : I used the same document. It's quite easy to understand. Is there anything i missed?
@Dex4u : 20 test pc. hmm!

Code: Select all

   mov   eax,2
   mov   ebx,20
   mul   ebx
   mov   ebx,hda
   add   ebx,eax
   call   HDD_wait_ready

   mov   al,0x0
   mov   dx,[ebx]
   add   dx,06
   or   eax,[ebx+8]
   out   dx,al

   call   HDD_wait_ready

   mov   dx,[ebx+4]
   mov   al,1000b
   out   dx,al

   mov   dx,[ebx]
   add   dx,0x07
   mov   al,0xA0
   out   dx,al

   mov   ecx,0xFFFF
.waitloop:
   loopnz   .waitloop

   call   HDD_ready_DRQ

   xor   edx,edx
   mov   ecx,5
   mov   esi,CD_COMMAND_PACKET
   cld

.next_command:
   mov   dx,[ebx]
   mov   ax,[esi]
   out   dx,ax
   add   esi,2
   dec   ecx
   jnz   .next_command

   mov   dx,[ebx]
   mov   ax,[esi]
   out   dx,ax

   call   HDD_wait_ready