Re: Fscking Pointers.

Liste des GroupesRevenir à cs raspberry-pi 
Sujet : Re: Fscking Pointers.
De : dave (at) *nospam* davehigton.me.uk (David Higton)
Groupes : comp.sys.raspberry-pi
Date : 26. Mar 2025, 21:14:18
Autres entêtes
Organisation : Home
Message-ID : <4af4ce035c.DaveMeUK@BeagleBoard-xM>
References : 1
User-Agent : Messenger-Pro/8.03 (MsgServe/8.01) (RISC-OS/5.31) NewsHound/v1.55
In message <vs1jgs$2co6s$3@dont-email.me>
          The Natural Philosopher <tnp@invalid.invalid> wrote:

It seems C has caught the disease of 'we will modify your code according
to what WE think it means'..
 
..my pointers to 254 byte structures are going haywire when I add 256
bytes to them...I have to add one instead... ..add that to the fact that to
write to flash RAM you need to specify  the *offset* from flash RAM base,
but to read it you need to use the  actual hardware address...
 
sigh.
 
What is the generic type for a simple pointer to presumably bytes, in ARM
C? Or should I resign myself to doing everything in 256byte chunks? the
structure to be read and written from Flash  is exactly that big for
obvious hardware reasons...

Pointers in C are incremented by the size of whatever they point to.

Yes, I've found it very frustrating in the past, too.

If you want to increment by one byte, you are clearly wanting to point
to something within the struct, so, point at the struct member rather
than the overall struct; and make sure that the member is amenable to
being addressed byte by byte.  If necessary, create a union with a byte
array.

David

Date Sujet#  Auteur
26 Mar 25 * Fscking Pointers.8The Natural Philosopher
26 Mar 25 +- Re: Fscking Pointers.1Lawrence D'Oliveiro
26 Mar 25 +* Re: Fscking Pointers.3Andy Burns
27 Mar 25 i`* Re: Fscking Pointers.2Theo
27 Mar 25 i `- Re: Fscking Pointers.1The Natural Philosopher
26 Mar 25 `* Re: Fscking Pointers.3David Higton
27 Mar 25  +- Re: Fscking Pointers.1Lawrence D'Oliveiro
27 Mar 25  `- Re: Fscking Pointers.1The Natural Philosopher

Haut de la page

Les messages affichés proviennent d'usenet.

NewsPortal