Re: [Freemint-discuss] USB bug

[David G. <dga...@gm...>]

2018-08-01 22:25 GMT+02:00 Roger Burrows <an...@xp...>:
> Indeed, when the length is odd, the last bytes are handle incorrectly, but I
> wasn't able to figure out a simple way of forcing an odd length to a device for
> testing.  But that's a separate bug, and wouldn't cause any problems with
> memory sticks AFAICS.  The bug is that the entire sector is byte-swapped.
>
> To prove it, first I wrote a simple program that uses Rwabs() to read the boot
> sector of a FAT16 file system into both an unaligned & a word-aligned buffer.
> The results are different: all of the data in the unaligned buffer is
> byte-swapped.
>
> Having done that, I wrote another program using Rwabs() to write to a sector
> using both aligned and unaligned buffers, and to read back the contents into a
> word-aligned buffer.  Again, the bytes are swapped when the sector is written
> from the unaligned buffer.
>
> It's probably faster for you to write the programs yourself, but if you need
> them, I can dig them out.  Be warned, they are hacks of other programs so the
> source is a bit ugly, and they are written for LatticeC.
>

Thanks for the explanation! I'll fix this.