[En-Nut-Discussion] GenChar driver, GenCharOpen

Harald Kipp harald.kipp at egnite.de
Thu Feb 4 10:52:54 CET 2010


Hi Curtis,

Curtis Maloney wrote:
>      NUTFILE *fp = (NUTFILE *) (dev->dev_dcb);
> 
>      if ((fp = malloc(sizeof(NUTFILE))) == 0) {
>          return NUTFILE_EOF; /* No memory. */
>      }
...
> Why does it set fp to dev->dev_dcb, only to then overwrite it with a malloc?

Good question. ;-)

In this case the first assignment is superfluous.

There are indeed simple drivers, which use dev_dcb as a pointer to a
static NUTFILE descriptor. But in this case the descriptor is
dynamically created and dev_dcb can be used for other purposes.

Harald




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