TDA4M How to change PhyBufPtr to VirtBufPtr

Hi Zhao,

Are you using 6.1 release? 

This release uses ion memory allocater.  ion has different mechanism for sharing buffer. 

Also if you are running two graphs in app1 and app2, this would need some changes, which will be available in the next release.

Rgds,

Brijesh

TO add to this the recommended way to exchange buffers between processes is below.

Every memory allocated using ION has a file descriptor. One can exchange file descriptors between process using unix domain sockets, see below

Given a virtual pointer you can get file descriptor using below API,

appMemGetDmaBufFd(virtAddr, &bufFd)

Here the virtual pointer MUST have been allocated using appMemAlloc()

bufFd can be passed to other process using unix domain socket.

On the other side you can map this bufFd to get virtual address on that process.

We don't have a utility API for this, but you can see how this is done in void *appMemAlloc(uint32_t block, uint32_t size, uint32_t align)

Specfically below lines ...

        virtual_ptr = mmap((void *)0x00000000u,
                           size,
                           PROT_WRITE | PROT_READ,
                           MAP_SHARED,
                           dma_buf_fd,
                           0u
                           );

The functions are in file vision_apps/utils/mem

regards
Kedar

Hi Zhao,

Any further question on this? Let us know if we can close this thread..

Rgds,

Brijesh

Hi Brijesh

Sorry for not repy in time . I just got invited to join J721E today.

I am using 06.00.01 release.

QNX is used ,so when I call  appMemGetDmaBufFd , I got bufFd=0;

what mechanism could I use to  share buffer in QNX?

Rgds,

Zhao Shiming