[FAQ] [参考译文] [常见问题解答] RPMsg：如何将多个端点添加到运行 RTOS 的远程内核中？

代码发生变化

附加的补丁添加了两个可被用来与 Linux 用户空间通信的额外的 RPMSg 端点：

e2e.ti.com/.../4760.0001_2D00_Linux_5F00_RPMsg_5F00_Echo_2D00_add_2D00_additional_2D00_endpoints.patch

关键详细信息  

每个附加的端点使用为 Linux 用户空间定义的相同的 RPMSG 服务名称"rpmsg_chrdev"。

将与 Linux 用户空间通信的 RPMSg 端点的预期服务名称在 Linux rpmsg_char 驱动程序中定义。

每个端点需要在 RTOS 端代码中有一个具有唯一信标的单独 RPMessage_Object。

TI 对此进行测试的方法是在 RTOS 端代码中为每个端点分配单独的任务。

附录

如何应用和构建代码？  

对于不熟悉应用 Git 补丁文件的客户、我在 Linux 终端上使用此过程：

$ cd location/of/mcu+/sdk
$ git status
// we see no git repo has been created yet
$ git init
$ git add .
// create the initial commit by adding everything in the SDK
// this works best with a fresh SDK installation
$ git branch
// the master branch is the only branch
$ git branch featureBranchName
$ git checkout featureBranchName
// copy over the patch file
// now we can apply the patch
$ git apply patchFileName

现在我可生成项目：

make -s -C examples/drivers/ipc/ipc_rpmsg_echo_linux/am64x-evm/r5fss0-0_freertos/ti-arm-clang all

有关通过终端 makefile 构建特定工程的更多信息、请参阅 MCU+ SDK 文档： https://software-dl.ti.com/mcu-plus-sdk/esd/AM64X/08_06_00_45/exports/docs/api_guide_am64x/MAKEFILE_BUILD_PAGE.html#MAKEFILE_EXAMPLE_BUILD

如何加载并测试固件？

有关从 Linux 将特定二进制文件加载到远程内核中的详细信息、请参阅 Linux Academy： https://dev.ti.com/tirex/explore/node?a=7qm9DIS__LATEST&node=A__ANKEb6LZY6VAX.9xvGwQ-g__linux_academy_am64x__7qm9DIS__LATEST

有关测试 IPC 的更多信息、请参阅 Linux Academy： https://dev.ti.com/tirex/explore/node?a=7qm9DIS__LATEST&node=A__AAtN.uvfmDSx4mvQ7f4R.w__linux_academy_am64x__7qm9DIS__LATEST

如果在 AM64x 上测试提供的补丁、我的输出应该是什么样的？  

// code is running on R5F0_0, so use RPROC_ID 2

root@am64xx-evm:~# rpmsg_char_simple -r 2 -n 3 -d rpmsg_chrdev -p 14
Created endpt device rpmsg-char-2-986, fd = 3 port = 1024
Exchanging 3 messages with rpmsg device ti.ipc4.ping-pong on rproc id 2 ...

Sending message #0: hello there 0!
Receiving message #0: hello there 0!
Sending message #1: hello there 1!
Receiving message #1: hello there 1!
Sending message #2: hello there 2!
Receiving message #2: hello there 2!

Communicated 3 messages successfully on rpmsg-char-2-986

TEST STATUS: PASSED
root@am64xx-evm:~# rpmsg_char_simple -r 2 -n 3 -d rpmsg_chrdev -p 15
Created endpt device rpmsg-char-2-988, fd = 3 port = 1024
Exchanging 3 messages with rpmsg device ti.ipc4.ping-pong on rproc id 2 ...

Sending message #0: hello there 0!
Receiving message #0: hello there 0!
Sending message #1: hello there 1!
Receiving message #1: hello there 1!
Sending message #2: hello there 2!
Receiving message #2: hello there 2!

Communicated 3 messages successfully on rpmsg-char-2-988

TEST STATUS: PASSED
root@am64xx-evm:~# rpmsg_char_simple -r 2 -n 3 -d rpmsg_chrdev -p 16
Created endpt device rpmsg-char-2-990, fd = 3 port = 1024
Exchanging 3 messages with rpmsg device ti.ipc4.ping-pong on rproc id 2 ...

Sending message #0: hello there 0!
Receiving message #0: hello there 0!
Sending message #1: hello there 1!
Receiving message #1: hello there 1!
Sending message #2: hello there 2!
Receiving message #2: hello there 2!

Communicated 3 messages successfully on rpmsg-char-2-990

TEST STATUS: PASSED

// now let's see what happens if you talk to a nonexistent endpoint

root@am64xx-evm:~# rpmsg_char_simple -r 2 -n 3 -d rpmsg_chrdev -p 17
_rpmsg_char_find_ctrldev: could not find the matching rpmsg_ctrl device for virtio1.rp
msg_chrdev.-1.17
Can't create an endpoint device: Success
TEST STATUS: FAILED