How to write dada into device memory

QNX Newsgroups (Archives) qnx.ddk
1

I am write a pci device(reflecting memory card),the Base Address is a
memory address, and I use the
mmap_device_memory() function to map the address, then use this mapped
address as a memory pointer.Use offset to the poiter i can read data
receive from other card.But when i write data into device using the
same way,offset of the pointer,other card can’t receive the
data.Maybe the data can’t write into the device .
Also i use the Base Address as pointer to write data,but it shows
memory dumped.
How to write dada into device memory?
Thank you.

2

“binfengpan” <binfengpan@hotmail-dot-com.no-spam.invalid> wrote in message
news:edn1tq$phh$1@inn.qnx.com…

I am write a pci device(reflecting memory card),the Base Address is a
memory address, and I use the
mmap_device_memory() function to map the address, then use this mapped
address as a memory pointer.Use offset to the poiter i can read data
receive from other card.But when i write data into device using the
same way,offset of the pointer,other card can’t receive the
data.Maybe the data can’t write into the device .

This sounds ok. Some card have more then one base address, are you sure you
are using the rightone.

Also i use the Base Address as pointer to write data,but it shows
memory dumped.

You can’t you must use the Base Address with mmap_device_memory(). This is
normal since the base address is a physical address and QNX used virtual
addressing.

How to write dada into device memory?

Maybe that device needs to be enabled somehow.

Thank you.