Memory mapped device access in Linux
 

I am trying to access (read/write) a memory mapped device in Linux using a C program.

Currently I am using the following piece of code in order to write data to the device.

tsuAddress[0]=0xb0000; //The address of the device is 0xb0000
tsuFileDescriptor[0] = open("/dev/mem", O_RDWR) ;

lseek(tsuFileDescriptor[0],tsuAddress[0], SEEK_SET);
write(tsuFileDescriptor[0],&dataToWrite,4);

Although data are finally sent to the device, they are NOT sent IMMEDIATELY after the write() function has completed (as I understand, the Operating System makes some buffering prior to sending the data to the device).

To be more specific, what I want is for the data to be sent to the memory mapped device IMMEDIATELY after the write() function executes.


Thanking you in advance, TSIK
www.tsik.eu

make some realtime FIFO files in the dev directory
they get a much higher scheduling priority
rtf_create()
rtf_put()
rtf_get()