I know that I should know how to do this, but for some reason it is
escapeing me right now and I was hoping someone here could help. I
need to setup a pointer to the memory location 0x30000000. I am
working on a linux system that has hardware inputs remapped to that
address and I have to read them. I am just drawing a blank on how to
actually assign the address of a pointer to point to.
7  1321 
PullnOutHair wrote: I know that I should know how to do this, but for some reason it is
escapeing me right now and I was hoping someone here could help. I
need to setup a pointer to the memory location 0x30000000. I am
working on a linux system that has hardware inputs remapped to that
address and I have to read them. I am just drawing a blank on how to
actually assign the address of a pointer to point to.
You don't do it in userland. That said.
assert(sizeof(v oid*) >= sizeof(unsigned long))
void* ptr = reinterpret_cas t<void*>(0x3000 0000UL);
red floyd <no*****@here.d ude> wrote in message news:<ID******* *********@newss vr27.news.prodi gy.com>... You don't do it in userland. That said.
What do you mean?
assert(sizeof(v oid*) >= sizeof(unsigned long))
void* ptr = reinterpret_cas t<void*>(0x3000 0000UL);
"PullnOutHa ir" <di*********@ho tmail.com> wrote in message
news:ca******** *************** ***@posting.goo gle.com... red floyd <no*****@here.d ude> wrote in message
news:<ID******* *********@newss vr27.news.prodi gy.com>... You don't do it in userland. That said.
What do you mean? http://info.astrian.net/jargon/terms/u/userland.html
Jonathan
PullnOutHair wrote: I know that I should know how to do this, but for some reason it is
escapeing me right now and I was hoping someone here could help. I
need to setup a pointer to the memory location 0x30000000. I am
working on a linux system that has hardware inputs remapped to that
address and I have to read them. I am just drawing a blank on how to
actually assign the address of a pointer to point to.
Assuming that the platform will allow you, and assuming the pointer is
of type whatever, you can do:
whatever *p = reinterpret_cas t<whatever *>(0x30000000) ;
Regards,
Ioannis Vranos http://www23.brinkster.com/noicys
Ioannis Vranos posted: PullnOutHair wrote:
I know that I should know how to do this, but for some
reason it is escapeing me right now and I was hoping someone here
could help. I need to setup a pointer to the memory location
0x30000000. I am working on a linux system that has hardware inputs
remapped to that address and I have to read them. I am just drawing a
blank on how to actually assign the address of a pointer to point to.
Assuming that the platform will allow you, and assuming
the pointer is of type whatever, you can do:
whatever *p = reinterpret_cas t<whatever *>(0x30000000) ;
Regards,
Ioannis Vranos
http://www23.brinkster.com/noicys
Should the "volatile" keyword be in there at all?
-JKop
JKop wrote: Ioannis Vranos posted:
whatever *p = reinterpret_cas t<whatever *>(0x30000000) ;
Should the "volatile" keyword be in there at all?
-JKop
Depends on whether it's data that can change out from underneath him.
My favorite variant of this (embedded system, C, not C++) was:
const volatile unsigned long * const PREGISTER =
(const volatile unsigned long *) 0xC0000000L;
It was a read-only memory mapped register.
JKop wrote: whatever *p = reinterpret_cas t<whatever *>(0x30000000) ;
Should the "volatile" keyword be in there at all?
volatile is used when the value of the variable can change between reads
outside of the program (e.g. an external thermometer). It has as a
result the compiler to not perform some optimisations.
Regards,
Ioannis Vranos http://www23.brinkster.com/noicys This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics | |
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