110 lines
4.0 KiB
Markdown
110 lines
4.0 KiB
Markdown
# RPMsg Design Document
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RPMsg is a framework to allow communication between two processors.
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RPMsg implementation in OpenAMP library is based on virtio. It complies
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the RPMsg Linux kernel implementation. It defines the handshaking on
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setting up and tearing down the communication between applicaitons
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running on two processors.
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## RPMsg User API Flow Chats
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### RPMsg Static Endpoint
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### Binding Endpoint Dynamically with Name Service
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### Creating Endpoint Dynamically with Name Service
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## RPMsg User APIs
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* RPMsg virtio master to initialize the shared buffers pool(RPMsg virtio slave
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doesn't need to use this API):
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```
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void rpmsg_virtio_init_shm_pool(struct rpmsg_virtio_shm_pool *shpool,
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void *shbuf, size_t size)
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```
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* Initialize RPMsg virtio device:
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```
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int rpmsg_init_vdev(struct rpmsg_virtio_device *rvdev,
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struct virtio_device *vdev,
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rpmsg_ns_bind_cb ns_bind_cb,
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struct metal_io_region *shm_io,
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struct rpmsg_virtio_shm_pool *shpool)
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```
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* Deinitialize RPMsg virtio device:
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```
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void rpmsg_deinit_vdev(struct rpmsg_virtio_device *rvdev)`
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```
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* Get RPMsg device from RPMsg virtio device:
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```
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struct rpmsg_device *rpmsg_virtio_get_rpmsg_device(struct rpmsg_virtio_device *rvdev)
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```
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* Create RPMsg endpoint:
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```
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int rpmsg_create_ept(struct rpmsg_endpoint *ept,
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struct rpmsg_device *rdev,
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const char *name, uint32_t src, uint32_t dest,
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rpmsg_ept_cb cb, rpmsg_ns_unbind_cb ns_unbind_cb)
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```
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* Destroy RPMsg endpoint:
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```
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void rpmsg_destroy_ept(struct rpsmg_endpoint *ept)
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```
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* Check if the local RPMsg endpoint is binded to the remote, and ready to send
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message:
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```
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int is_rpmsg_ept_ready(struct rpmsg_endpoint *ept)
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```
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* Send message with RPMsg endpoint default binding:
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```
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int rpmsg_send(struct rpmsg_endpoint *ept, const void *data, int len)
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```
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* Send message with RPMsg endpoint, specify destination address:
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```
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int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len,
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uint32_t dst)
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```
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* Send message with RPMsg endpoint using explicit source and destination
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addresses:
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```
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int rpmsg_send_offchannel(struct rpmsg_endpoint *ept,
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uint32_t src, uint32_t dst,
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const void *data, int len)
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```
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* Try to send message with RPMsg endpoint default binding, if no buffer
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available, returns:
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```
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int rpmsg_trysend(struct rpmsg_endpoint *ept, const void *data,
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int len)
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```
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* Try to send message with RPMsg endpoint, specify destination address,
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if no buffer available, returns:
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```
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int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len,
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uint32_t dst)
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```
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* Try to send message with RPMsg endpoint using explicit source and destination
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addresses, if no buffer available, returns:
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```
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int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept,
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uint32_t src, uint32_t dst,
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const void *data, int len)`
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```
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## RPMsg User Defined Callbacks
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* RPMsg endpoint message received callback:
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```
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int (*rpmsg_ept_cb)(struct rpmsg_endpoint *ept, void *data,
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size_t len, uint32_t src, void *priv)
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```
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* RPMsg name service binding callback. If user defines such callback, when
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there is a name service announcement arrives, if there is no registered
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endpoint found to bind to this name service, it will call this callback.
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If this callback is not defined, it will drop this name service.:
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```
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void (*rpmsg_ns_bind_cb)(struct rpmsg_device *rdev,
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const char *name, uint32_t dest)
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```
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* RPMsg endpoint name service unbind callback. If user defines such callback,
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when there is name service destroy arrives, it will call this callback to
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notify the user application about the remote has destroyed the service.:
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```
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void (*rpmsg_ns_unbind_cb)(struct rpmsg_endpoint *ept)
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```
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