in8() or out8()

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#1

Hello,

Anybody knows how to use in8() or out8() ? Is it the same use as inb() or
outb() in Linux, setting all ports turn on and run it
with root privilege?

Thanks,

Belinda

#2

Belinda <yye@borg.cs.dal.ca> wrote:

Hello,

Anybody knows how to use in8() or out8() ? Is it the same use as inb() or
outb() in Linux, setting all ports turn on and run it
with root privilege?

in8() and out8() read/write 8 bytes to a control register/io-port.
You need hardware privilege to use them – see the ThreadCtl() function
for this, and you need root (super user) access to succeed with the
ThreadCtl().

-David

QNX Training Services
dagibbs@qnx.com

#3

“David Gibbs” <dagibbs@qnx.com> wrote in message
news:9qkub4$nro$1@nntp.qnx.com…

Belinda <> yye@borg.cs.dal.ca> > wrote:
Hello,

Anybody knows how to use in8() or out8() ? Is it the same use as inb()
or
outb() in Linux, setting all ports turn on and run it
with root privilege?

in8() and out8() read/write 8 bytes to a control register/io-port.
You need hardware privilege to use them – see the ThreadCtl() function
for this, and you need root (super user) access to succeed with the
ThreadCtl().

It’s also good pratice to obtain the address to pass to in*/ou*
via mmap_device_io. It increases portability to other platform.

-David

QNX Training Services
dagibbs@qnx.com

#4

Hi,

Thanks for your solution. I tried it. And it still has some errors. I just
write a simple code , followed as :

#include <hw/inout.h>
#include <sys/neutrino.h>
#define BASE_ADDRESS 0x300
#define DEBUG

int main()
{
unsigned char byteToPort;
unsigned char byteFromPort;

if (ThreadCtl(_NTO_TCTL_IO,0)==-1) {
#ifdef DEBUG
printf(“ThreadCtl return error!”);
#endif
return -1;
}else {
#ifdef DEBUG
printf(“ThreadCtl() return success!”);
#endif
}

byteToPort=‘h’;
out8(BASE_ADDRESS, byteToPort);
#ifdef DEBUG
printf(“write success!”);
#endif
byteFromPort=in8(BASE_ADDRESS);

#ifdef DEBUG
printf(“IN_PORT: %s /n”, byteFromPort);
#endif
return 0;

}

\

With the root of privilege, I run the above code and it is reported the
error of memory dumption. I found this error is caused by using in8()
functio and it seems that outb() can work. I couldn’t know what’s the
reason caused it happened.

And if I don’t use root priviledge, do you think I can find the other ways
to solve it?

Thanks,

Belinda





“David Gibbs” <dagibbs@qnx.com> wrote in message
news:9qkub4$nro$1@nntp.qnx.com…

Belinda <> yye@borg.cs.dal.ca> > wrote:
Hello,

Anybody knows how to use in8() or out8() ? Is it the same use as inb()
or
outb() in Linux, setting all ports turn on and run it
with root privilege?

in8() and out8() read/write 8 bytes to a control register/io-port.
You need hardware privilege to use them – see the ThreadCtl() function
for this, and you need root (super user) access to succeed with the
ThreadCtl().

-David

QNX Training Services
dagibbs@qnx.com

#5

“Belinda” <yye@borg.cs.dal.ca> wrote in message
news:9qnsbt$7at$1@inn.qnx.com…

Hi,

Thanks for your solution. I tried it. And it still has some errors. I just
write a simple code , followed as :

[cut]

#ifdef DEBUG
printf(“IN_PORT: %s /n”, byteFromPort);
#endif
You are trying to print byteFromPort as if it was a string.

Printf uses byteFromPort as a pointer which most obviously

doesn’t point in valid address space. Try 0x%x instead

to show the value in hexadecimal.