RPMsg name service

RPMsg name service (<tt>rpmsg_ns.c</tt>)

**RT_RPMSG_DRIVER_EXPORT(rpmsg_ns_driver)** — matches **id.name = "rpmsg-name-service"** (second **rt_rpmsg_device** from **virtio-rpmsg.c** when **VIRTIO_RPMSG_F_NS**).

Stack context: RPMsg.

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Fixed endpoint

**rpmsg_ns_probe** creates:

Field	Value
**info.name**	"name-service"
**src / dst**	**RT_RPMSG_NS_ADDR (0x35)**
RX	**rpmsg_ns_rx_callback**

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Wire message

struct rt_rpmsg_ns_msg {
    char name[32];
    le32 addr;
    le32 flags;   /* RT_RPMSG_NS_CREATE or RT_RPMSG_NS_DESTROY */
};

**rpmsg_ns_rx_callback**:

Flag	Action
CREATE	**rt_rpmsg_create_endpoint(rdev, &info, NULL)** → driver **rx_callback** fallback
DESTROY	**find_endpoint** + **destroy_endpoint**

**virtio_rpmsg** routes packets with **dst == 0x35** to **vrpmsg->ns** device, not the char device.

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Local CREATE side

When **virtio_rpmsg_create_endpoint** runs on a local endpoint and **supp_ns**:

• Sends NS CREATE to **RT_RPMSG_NS_ADDR** with **addr = ept->info.src** (little-endian on wire)

Remote can then open the announced channel.

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Pitfalls

Issue	Mitigation
Endianness	**addr** is le32 on wire
CREATE without consumer	Orphan endpoints until DESTROY
Only master has NS feature	**rpmsg_virtio_get_features** sets **VIRTIO_RPMSG_F_NS** on master

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See also

• RPMsg
• RPMsg character device
• components/drivers/rpmsg/rpmsg_ns.c