On Thu, 29 Mar 2001, Peter Lueg wrote:
> Hi, list
>
> anybody who can tell me how to access 16Bit PCMCIA memory while still using
> longs? If I try to copy a mmapped region from PCMCIA memory space to some
> buffer
> using memcpy, I apparently only get the lower half words copied, the upper ones
> containing garbage.
>
> Can I tell the compile how to handle certain variables so that he generates
> half word accesses automagically?
>
> Do I have to write my own memcpy which uses 16Bit acceses only or is there an
> alternate routine which does the job?
You should craft your own. Something like the following might do what you
want:
memcpy_from_pcmcia(void *dst, const void *src, int nbr)
{
const unsigned short *s = src;
unsigned long *d = *dst;
while (nbr--) {
*d++ = (s[0] | (s[2] << 16));
s += 2;
}
}
memcpy_to_pcmcia(void *dst, void *src, int nbr)
{
const unsigned long *s = src;
unsigned short *d = dst;
while ((nbr -= 2) > 0) {
*d = *s;
d += 2;
*d = *s >> 16;
d += 2;
s++;
}
}
Completely untested though.
Nicolas
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