Re: [lwip-users] lwip_standard_chksum()

[Timmy Brolin]

Leon Woestenberg wrote:

> Hello Curt,
>
> first look through the code, my brain triggered on something in memory 
> that seemed to have survived time despite wear and beer:
>
> > lwip_standard_chksum2(void *dataptr, int len)
> > {
> >  u8_t *pb = dataptr;
> >  u16_t *ps, t = 0;
> >  u32_t sum = 0;
> >  int odd = ((u32_t)pb & 1);
> >
> >  /* Get aligned to u16_t */
> >  if (odd && len > 0) {
> >    ((u8_t *)&t)[1] = *pb++;
> >  
> This fetches a 16-bit word, possible on a non-16 bit aligned address. 
> Some CPU's will puke at this point and stop execution. I wish I could 
> name a few CPUs with 100% certainty but I cannot now, though I am sure 
> have come across this on some 16 and 32-bit platforms. 

Where? I can't see a 16bit fetch there.

Timmy Brolin