[SeaBIOS] Wrong address returned by container _of macro

[Daniel Castro]

On Wed, Apr 4, 2012 at 4:04 PM, Daniel Castro <evil.dani at gmail.com> wrote:
> Hello All,
>
> I have a little problem, when I try to get my drive on boot (16bit) I
> am getting the wrong address:
>
> This code:
>        struct xendrive_s * xendrive =
> GLOBALFLAT2GLOBAL(container_of(GET_GLOBAL(op->drive_g), struct
> xendrive_s, drive));
>        dprintf(1,"Xendrive at:%p\n",xendrive);
> Returns this:
> Xendrive at:0xfff10000
>
> But it should be this instead:
> dprintf(1,"TEST drive 0 %p \n",i,GET_GLOBAL(xendrives[0]));
> returns this:
> TEST drive 0 0x000fd620
>
> This last address is the address returned when done this:
>        struct xendrive_s *xd = malloc_fseg(sizeof(struct xendrive_s*));
>        SET_FLATPTR(xendrives[count_drives],xd);
> The xd pointer is later used for:
> boot_add_hd(&xd->drive,desc,drives);
>
> Any tip to solve this will be greatly appreciated.

I found a way around it, I create a global array with the drives as I
add them to the boot, when the read operation is called, I compare the
op->drive address to the ones I have registered, that way I can
recover the struct that contains the drive and my custom struct for
the drive.

>
> Thanks you all,
>
> Daniel
>
>
>
>
>
> --
> +-=====---------------------------+
> | +---------------------------------+ | This space intentionally blank
> for notetaking.
> | |   | Daniel Castro,                |
> | |   | Consultant/Programmer.|
> | |   | U Andes                         |
> +-------------------------------------+



-- 
+-=====---------------------------+
| +---------------------------------+ | This space intentionally blank
for notetaking.
| |   | Daniel Castro,                |
| |   | Consultant/Programmer.|
| |   | U Andes                         |
+-------------------------------------+