9.100ASK_V853-PRO開發板支持E907小核開發

0.前言

? 100ASK_V853-PRO開發板的V853芯片集成Arm Cortex-A7和RISC-V E907 雙CPU，玄鐵E907 是一款完全可綜合的高端 MCU 處理器。它兼容 RV32IMAC 指令集，提供可觀的整型性能提升以及高能效的浮點性能。E907 的主要特性包括：單雙精度浮點單元，以及快速中斷響應。下圖為RISC-V E907 核的介紹。

本章主要講述如何E907小核進行開發并與Arm A7大核進行通信。

平頭哥E907官網：https://www.t-head.cn/product/E907?spm=a2ouz.12986968.0.0.7bfc2cbdcYnL2b

E907芯片資源下載中心：https://occ.t-head.cn/community/download?id=3916180248689188864

全志E907開發指南：https://tina.100ask.net/SdkModule/Linux_E907_DevelopmentGuide-01/

Yuzuki大佬的V85x E907 小核開發與使用：https://www.gloomyghost.com/live/20230215.aspx

1.配置E907環境

E907_RTOS BSP包：https://github.com/YuzukiHD/Yuzukilizard/tree/master/Software/BSP/e907_rtos

E907編譯工具鏈： https://github.com/YuzukiHD/Yuzukilizard/releases/download/Compiler.0.0.1/riscv64-elf-x86_64-20201104.tar.gz

感謝Yuzuki大佬的V851S的倉庫提供的E907_RTOS源碼，這里我將E907開發包放在百度網盤中，方便大家獲取。鏈接為：

鏈接：https://pan.baidu.com/s/1TX742vfEde9bMLd9IrwwqA?pwd=sp6a
提取碼：sp6a

您可以在百度網盤的V853資料光盤中09_E907開發包中獲取到e907_rtos.tar.gz

1.1 編譯E907源碼

將下載完成的E907開發包放在任意目錄下，假設放在/home/book/workspaces目錄下

book@100ask:~/workspaces$ ls
e907_rtos.tar.gz   

解壓e907源碼壓縮包，輸入tar -xzvf e907_rtos.tar.gz ，例如：

book@100ask:~/workspaces$ tar -xzvf e907_rtos.tar.gz 
e907_rtos/
e907_rtos/README.md
e907_rtos/rtos/
e907_rtos/rtos/LICENSE
e907_rtos/rtos/toolchain/
e907_rtos/rtos/toolchain/riscv64-elf-x86_64-20201104/
e907_rtos/rtos/toolchain/riscv64-elf-x86_64-20201104/libexec/
e907_rtos/rtos/toolchain/riscv64-elf-x86_64-20201104/libexec/gcc/
...

解壓完成后，進入e907源碼目錄

book@100ask:~/workspaces$ cd e907_rtos/
book@100ask:~/workspaces/e907_rtos$ ls
README.md  rtos  rtos-hal

進入rtos/source/目錄下

book@100ask:~/workspaces/e907_rtos$ cd rtos/source/
book@100ask:~/workspaces/e907_rtos/rtos/source$ ls
disfunc.sh  ekernel   envsetup.sh  Kbuild   Kconfig.melis     Makefile      modules.order  platform.txt  scripts
drivers     emodules  include      Kconfig  Kconfig.platform  melis-env.sh  out            projects      tools

配置編譯環境變量，輸入source melis-env.sh

book@100ask:~/workspaces/e907_rtos/rtos/source$ source melis-env.sh

輸入lunch選中對應的開發板

book@100ask:~/workspaces/e907_rtos/rtos/source$ lunch

You're building on Linux 100ask 5.4.0-148-generic #165~18.04.1-Ubuntu SMP Thu Apr 20 01:14:06 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

Lunch menu... pick a combo:
The supported board:
    1. v851-e907-lizard
    2. v851-e907-lizard-tinymaix
    3. v853-e907-100ask
    4. v853-e907-100ask-tinymaix
What is your choice? 

此時輸入3，并按回車。選擇v853-e907-100ask方案，選擇完成后會如下所示

book@100ask:~/workspaces/e907_rtos/rtos/source$ lunch

You're building on Linux 100ask 5.4.0-148-generic #165~18.04.1-Ubuntu SMP Thu Apr 20 01:14:06 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

Lunch menu... pick a combo:
The supported board:
    1. v851-e907-lizard
    2. v851-e907-lizard-tinymaix
    3. v853-e907-100ask
    4. v853-e907-100ask-tinymaix
What is your choice? 3
You have select v853-e907-100ask 
============================================
Project Based On Platform sun20iw3p1 v853-e907-100ask
============================================

此時即可進行編譯，輸入make

book@100ask:~/workspaces/e907_rtos/rtos/source$ make
scripts/kconfig/conf  --silentoldconfig Kconfig
  CHK     include/config/kernel.release
  CHK     include/generated/uapi/melis/version.h
fatal: not a git repository (or any parent up to mount point /)
Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).
fatal: not a git repository (or any parent up to mount point /)
Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).
fatal: not a git repository (or any parent up to mount point /)
Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).
fatal: not a git repository (or any parent up to mount point /)
Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).
  UPD     include/generated/uapi/melis/version.h
  CHK     include/generated/utsrelease.h
  CC      sysconfig.fex
  CC      ekernel/arch/common/common.o
  LD      ekernel/arch/common/built-in.o
  AS      ekernel/arch/riscv/sunxi/blobdata.o
  LD      ekernel/arch/riscv/sunxi/built-in.o
  LD      ekernel/arch/riscv/built-in.o
  LD      ekernel/arch/built-in.o
  LD      ekernel/built-in.o
  LD [M]  ekernel/melis30.o
/home/book/workspaces/e907_rtos/rtos/source/../toolchain/riscv64-elf-x86_64-20201104//bin/riscv64-unknown-elf-ld: ekernel/melis30.o: section .dram_seg.stack lma 0x43c3a2b8 adjusted to 0x43c3a34c
  OBJCOPY ekernel/melis30.bin
  RENAME  ekernel/melis30.o ----> ekernel/melis30.elf
/home/book/workspaces/e907_rtos/rtos/source/../toolchain/riscv64-elf-x86_64-20201104//bin/riscv64-unknown-elf-strip: ekernel/stW7SdkR: section .dram_seg.stack lma 0x43c3a2b8 adjusted to 0x43c3a34c

   text    data     bss     dec     hex filename
 221280   17132   25488  263900   406dc ekernel/melis30.elf

  pack    melis

#### make completed successfully (11 seconds) ####

編譯完成后會在當前目錄的ekernel/下生成一個melis30.elf文件，該文件即可用于啟動小核。

1.2 E907配置項

? E907開發包的配置與Tina SDK的配置類似，在e907_rtos/rtos/source目錄下，執行make menuconfig

例如：

book@100ask:~/workspaces/e907_rtos/rtos/source$ make menuconfig

執行完成后會進入如下界面：

2.加載E907小核

2.1 Tina配置

2.1.1 設備樹配置

? 在Tina根目錄下，進入設備樹目錄

book@100ask:~/workspaces/tina-v853-open$ cd device/config/chips/v853/configs/100ask/

編輯設備樹

book@100ask:~/workspaces/tina-v853-open/device/config/chips/v853/configs/100ask$ vi board.dts 

在設備樹文件中找到E907相關的設備樹節點，設備樹默認設置為：

reserved-memory {
                e907_dram: riscv_memserve {
                        reg = <0x0 0x48000000 0x0 0x00400000>;
                        no-map;
                };

                vdev0buffer: vdev0buffer@47000000 {
                        /* 256k reserved for shared mem pool */
                        compatible = "shared-dma-pool";
                        reg = <0x0 0x47000000 0x0 0x40000>;
                        no-map;
                };

                vdev0vring0: vdev0vring0@47040000 {
                        reg = <0x0 0x47040000 0x0 0x20000>;
                        no-map;
                };

                vdev0vring1: vdev0vring1@47060000 {
                        reg = <0x0 0x47060000 0x0 0x20000>;
                        no-map;
                };
        };

        e907_rproc: e907_rproc@0 {
                compatible = "allwinner,sun8iw21p1-e907-rproc";
                clock-frequency = <600000000>;
                memory-region = <&e907_dram>, <&vdev0buffer>,
                                                <&vdev0vring0>, <&vdev0vring1>;

                mboxes = <&msgbox 0>;
                mbox-names = "mbox-chan";
                iommus = <&mmu_aw 5 1>;

                memory-mappings =
                /* DA            len         PA */
                        /* DDR for e907  */
                        < 0x48000000 0x00400000 0x48000000 >;
                core-name = "sun8iw21p1-e907";
                firmware-name = "melis-elf";
                status = "okay";
        };

        rpbuf_controller0: rpbuf_controller@0 {
                compatible = "allwinner,rpbuf-controller";
                remoteproc = <&e907_rproc>;
                ctrl_id = <0>;  /* index of /dev/rpbuf_ctrl */
                iommus = <&mmu_aw 5 1>;
                status = "okay";
        };

        rpbuf_sample: rpbuf_sample@0 {
                compatible = "allwinner,rpbuf-sample";
                rpbuf = <&rpbuf_controller0>;
                status = "okay";
        };

由于我們需要使用uart3打印E907小核的打印信息，為防止內核搶占uart3，所以需要禁用uart3節點

&uart3 {
        pinctrl-names = "default", "sleep";
        pinctrl-0 = <&uart3_pins_active>;
        pinctrl-1 = <&uart3_pins_sleep>;
        uart-supply = ;
        status = "okay";
};

修改設備樹復用

uart3_pins_active: uart3@0 {
                allwinner,pins = "PH0", "PH1";
                allwinner,function = "uart3";
                allwinner,muxsel = <5>;
                allwinner,drive = <1>;
                allwinner,pull = <1>;
        };

        uart3_pins_sleep: uart3@1 {
                allwinner,pins = "PH0", "PH1";
                allwinner,function = "gpio_in";
                allwinner,muxsel = <0>;
        };

2.1.2 內核配置

在Tina根目錄下，執行make kernel_menuconfig，例如：

book@100ask:~/workspaces/tina-v853-open$ make kernel_menuconfig

1.使能硬件支持

進入內核配置界面后，進入Device Drivers 目錄，選中Mailbox Hardware Support，如下圖所示

選中后進入Mailbox Hardware Support目錄中，選中sunxi Mailbox和sunxi rv32 standby driver，選中完成后如下圖所示：

2.使能RPMsg驅動

進入如下目錄中

→ Device Drivers 
	→ Rpmsg drivers

選中如下配置

<*> allwinnertech rpmsg driver for v853-e907
<*> allwinnertech rpmsg hearbeat driver
<*> sunxi rpmsg ctrl driver
<*> Virtio RPMSG bus driver 

選中完成后如下圖所示：

3.使能共享內存驅動

? 進入如下目錄中

→ Device Drivers 
	→ Remoteproc drivers 

選中如下配置

<*> SUNXI remote processor support  --->

如下圖所示：

修改完成后，保存內核配置并退出。

2.1.3 編譯新鏡像

在Tina根目錄下，輸入make編譯剛剛選中的內核驅動，編譯完成后，輸入pack，打包生成新鏡像。例如：

book@100ask:~/workspaces/tina-v853-open$ make
...
book@100ask:~/workspaces/tina-v853-open$ pack
...

生成新鏡像后，將生成的v853_linux_100ask_uart0.img文件拷貝到Windows主機端。

2.2 E907配置

2.2.1 修改E907鏈接腳本

? 進入目錄e907_rtos/rtos/source/projects/v853-e907-100ask中，找到kernel.lds文件，該文件保存有E907小核的鏈接信息。

book@100ask:~/workspaces/e907_rtos/rtos/source/projects/v853-e907-100ask$ ls
configs  data  epos.img  kernel.lds  src  version

修改kernel.lds，找到MEMORY節點，修改起始地址為0x48000000，長度為0x00400000。此參數需要和Tina設備樹中的E907內存參數一致，所以可修改MEMORY節點參數為：

MEMORY
{
   /*DRAM_KERNEL: 4M */
   DRAM_SEG_KRN (rwx) : ORIGIN = 0x48000000, LENGTH = 0x00400000
}

兩者對比圖如下：

這里使用的0x48000000是假設V853擁有128M的內存，可設置十六進制為為0x48000000；長度為4M，十六進制為0x00400000

2.2.2 修改E907配置

進入e907_rtos/rtos/source/projects/v853-e907-100ask/configs目錄下，修改defconfig文件，例如：

book@100ask:~/workspaces/e907_rtos/rtos/source/projects/v853-e907-100ask$ cd configs/
book@100ask:~/workspaces/e907_rtos/rtos/source/projects/v853-e907-100ask/configs$ ls
defconfig  sys_config.fex

修改下面三個參數為：

CONFIG_DRAM_PHYBASE=0x48000000
CONFIG_DRAM_VIRTBASE=0x48000000
CONFIG_DRAM_SIZE=0x0400000

如下圖所示：

2.2.3 使用uart3輸出信息

1.修改引腳復用

配置引腳復用文件，進入e907_rtos/rtos/source/projects/v853-e907-100ask/configs目錄下

修改sys_config.fex文件，通過查詢數據手冊，查看引腳復用功能，我們使用PH0和PH1作為uart3功能

修改uart3節點為：

[uart3]
uart_tx         = port:PH00<5><1>
uart_rx         = port:PH01<5><1>

2.修改配置

在e907_rtos/rtos/source目錄下輸入make menuconfig，進入E907配置界面

進入如下目錄，選中[*] Support Serial Driver

 → Kernel Setup 
 	→ Drivers Setup 
 		→ Melis Source Support
 			[*] Support Serial Driver

進入如下目錄，選中[*] enable sysconfig，啟用讀取解析 sys_config.fex 功能

 → Kernel Setup 
 	→ Drivers Setup 
 		→ SoC HAL Drivers 
 			→ Common Option 
 				[*] enable sysconfig

進入如下目錄中，啟用uart驅動，并使用uart3。

 → Kernel Setup 
 	→ Drivers Setup 
 		→ SoC HAL Drivers 
 			→ UART Devices
 				[*] enable uart driver 
 				[*]   support uart3 device
 				(3)   cli uart port number 

進入如下目錄，啟用sys_config.fex 解析器

 → Kernel Setup 
 	→ Subsystem support 
 		→ devicetree support 
 			[*] support traditional fex configuration method parser. 

保存并退出E907配置。

2.2.4 編譯生成新鏡像

在workspaces/e907_rtos/rtos/source目錄下，輸入make

book@100ask:~/workspaces/e907_rtos/rtos/source$ make
  CHK     include/config/kernel.release
  CHK     include/generated/uapi/melis/version.h
fatal: not a git repository (or any parent up to mount point /)
Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).
fatal: not a git repository (or any parent up to mount point /)
Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).
fatal: not a git repository (or any parent up to mount point /)
Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).
fatal: not a git repository (or any parent up to mount point /)
Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).
  UPD     include/generated/uapi/melis/version.h
  CHK     include/generated/utsrelease.h
  CC      sysconfig.fex
  CC      ekernel/arch/common/common.o
  LD      ekernel/arch/common/built-in.o
  AS      ekernel/arch/riscv/sunxi/blobdata.o
  LD      ekernel/arch/riscv/sunxi/built-in.o
  LD      ekernel/arch/riscv/built-in.o
  LD      ekernel/arch/built-in.o
  LD      ekernel/built-in.o
  LD [M]  ekernel/melis30.o
/home/book/workspaces/e907_rtos/rtos/source/../toolchain/riscv64-elf-x86_64-20201104//bin/riscv64-unknown-elf-ld: ekernel/melis30.o: section .dram_seg.stack lma 0x4803a2b8 adjusted to 0x4803a34c
  OBJCOPY ekernel/melis30.bin
  RENAME  ekernel/melis30.o ----> ekernel/melis30.elf
/home/book/workspaces/e907_rtos/rtos/source/../toolchain/riscv64-elf-x86_64-20201104//bin/riscv64-unknown-elf-strip: ekernel/stWPSq13: section .dram_seg.stack lma 0x4803a2b8 adjusted to 0x4803a34c

   text    data     bss     dec     hex filename
 221280   17132   25488  263900   406dc ekernel/melis30.elf

  pack    melis

#### make completed successfully (7 seconds) ####

編譯完成后會在ekernel目錄下生成的melis30.elf。

2.3 檢查開發板硬件

? 經過測試發現在100ASK_V853-PRO開發板上的R36電阻會導致uart3波特率過高，所以需要檢查開發板上的R36電阻是否存在，如果存在需要手動去掉該電阻。下圖為存在R36電阻的位置情況，紅框內即為R36電阻

如果電阻存在需要手動去除，下圖為去除R36電阻的示意圖

去除R36電阻后，即可正常訪問uart3串口。

2.4 開發板內使能E907

使用全志燒寫工具AllwinnertechPhoeniSuit更新Tina新鏡像，詳情請參考https://forums.100ask.net/t/topic/2882

更新完成后，打開串口終端進入開發板控制臺，將melis30.elf拷貝到/lib/firmware目錄下。

假設我使用ADB功能將文件拷貝到開發板的root/目錄下

root@TinaLinux:~# cd /root/
root@TinaLinux:~# ls
melis30.elf

將root目錄下的melis30.elf拷貝到/lib/firmware目錄下

root@TinaLinux:~# cp melis30.elf /lib/firmware/
root@TinaLinux:~# ls /lib/firmware/
boot_xr829.bin   fw_xr829.bin     melis30.elf      sdd_xr829.bin
etf_xr829.bin    fw_xr829_bt.bin  regulatory.db

拷貝完成后，可以在/lib/firmware目錄下，看到小核固件。

2.4.1 連接開發板的uart3

? 此時需要使用USB轉串口模塊，連接我們上面設置的uart3。我們需要找到開發板上的PH0、PH1、GND，分別連接到USB轉串口模塊的RXD、TXD、GND。100ASK_V853-PRO開發板已經將PH0、PH1、GND引出來，位置圖圖下所示

具體的引腳可查看開發板背面的絲印，確認引腳位置。

通過背面的絲印可以知道PH0、PH1、GND的位置，如下圖所示，PH0、PH1、GND，分別連接到USB轉串口模塊的RX、TX、GND。

連接完成后將USB轉串口模塊插入windows主機端后，使用串口軟件打開uart3串口界面，波特率為115200。

在Tina Linux開發板串口終端輸入

root@TinaLinux:~# echo melis30.elf > /sys/kernel/debug/remoteproc/remoteproc0/firmware 

將melis30.elf固件放在硬件節點firmware 下，啟動E907固件

root@TinaLinux:~# echo start > /sys/kernel/debug/remoteproc/remoteproc0/state
[ 3926.510018]  remoteproc0: powering up e907_rproc
[ 3926.515440]  remoteproc0: failed to parser head (melis30.elf) ret=-2
[ 3926.522674]  remoteproc0: failed to read boot_package item
[ 3926.528930]  remoteproc0: request_firmware failed from boot_package: -14
[ 3926.537528] virtio_rpmsg_bus virtio0: rpmsg host is online
[ 3926.543964]  remoteproc0: registered virtio0 (type 7)
[ 3926.550538]  remoteproc0: remote processor e907_rproc is now up
root@TinaLinux:~# [ 3926.560537] virtio_rpmsg_bus virtio0: creating channel rpbuf-service addr 0x400
[ 3926.569199] virtio_rpmsg_bus virtio0: creating channel sunxi,rpmsg_heartbeat addr 0x401
[ 3926.578725] virtio_rpmsg_bus virtio0: creating channel sunxi,notify addr 0x402
[ 3926.587194] virtio_rpmsg_bus virtio0: creating channel sunxi,rpmsg_ctrl addr 0x403

使能后可以在另一個串口界面看到如下打印信息

|commitid: 
|halgitid: 
|timever : Thu, 04 May 2023 04:22:23 -0400

scheduler startup
msh >Start Rpmsg Hearbeat Timer
rpmsg ctrldev: Start Running...

按下回車即可進入終端界面。

輸入ps即可看見小核進程信息

msh >ps
thread                           pri  status      sp     stack size max used left tick  error
-------------------------------- ---  ------- ---------- ----------  ------  ---------- ---
tshell                            21  ready   0x000003e8 0x00004000    19%   0x00000008 000
ctrldev                            6  suspend 0x00000148 0x00001000    08%   0x0000000a 000
rpmsg_srm                          8  suspend 0x000000f8 0x00000800    22%   0x0000000a 000
vring-ipi                         15  suspend 0x00000118 0x00002000    03%   0x0000000a 000
rpbuf_init                         8  suspend 0x000000e8 0x00001000    12%   0x0000000a 000
standby                            1  suspend 0x00000128 0x00001000    07%   0x0000000a 000
tidle                             31  ready   0x00000178 0x00002000    04%   0x0000001e 000
timer                              8  suspend 0x000000d8 0x00000200    73%   0x0000000a 000

3.雙核通信

3.1 E907小核創建通訊節點

在E907小核串口終端建立兩個通訊節點用于監聽數據，輸入eptdev_bind test 2

msh >eptdev_bind test 2

查看監聽節點，輸入rpmsg_list_listen

msh >rpmsg_list_listen
name             listen  alive
test             2  0
console                  100  0

3.2 大核創建通訊節點

在Tina LInux下也創建兩個通訊監聽節點，輸入以下兩個命令

echo test > /sys/class/rpmsg/rpmsg_ctrl0/open
echo test > /sys/class/rpmsg/rpmsg_ctrl0/open

輸入后，如下所示：

root@TinaLinux:~# echo test > /sys/class/rpmsg/rpmsg_ctrl0/open
[ 5060.227158] virtio_rpmsg_bus virtio0: creating channel sunxi,rpmsg_client addr 0x404
s/rpmsg/rpmsg_ctrl0/openroot@TinaLinux:~# echo test > /sys/class/rpmsg/rpmsg_ctrl0/open
[ 5061.464758] virtio_rpmsg_bus virtio0: creating channel sunxi,rpmsg_client addr 0x405

在大核TIna Linux中也創建了兩個監聽節點，輸入ls /dev/rpmsg*查看節點信息

root@TinaLinux:~# ls /dev/rpmsg*
/dev/rpmsg0       /dev/rpmsg1       /dev/rpmsg_ctrl0

創建完成后，可以在E907小核終端中查看自動輸出的信息。

msh >ctrldev: Rx 44 Bytes
client: Rx 8 Bytes
rpmsg0: binding
send 0x13131411 to rpmsg0
create rpmsg0 client success
ctrldev: Rx 44 Bytes
client: Rx 8 Bytes
rpmsg1: binding
send 0x13131411 to rpmsg1
create rpmsg1 client success

3.3 大核傳輸至E907小核

在Tina LInux下輸入

echo "hello 100ASK_V853-PRO" > /dev/rpmsg0
echo "hello Tina Linux" > /dev/rpmsg1

將Linux Message 0信息通過創建的監聽節點傳輸到E907小核，例如：

root@TinaLinux:~# echo "hello 100ASK_V853-PRO" > /dev/rpmsg0
root@TinaLinux:~# echo "hello Tina Linux" > /dev/rpmsg1

輸入后，打開E907串口終端可以發現，大核傳輸過來的信息。

rpmsg0: Rx 22 Bytes
Data:hello 100ASK_V853-PRO

rpmsg1: Rx 17 Bytes
Data:hello Tina Linux

3.4 E907小核傳輸至大核

? 在小核端需要使用命令 eptdev_send 用法 eptdev_send ，這里的id號從0開始，我們設置有兩個通信節點，所以id號分別為0和1。

? 在小核的串口終端輸入以下命令：

eptdev_send 0 "hello E907"
eptdev_send 1 "hello E907"

例如：

msh >eptdev_send 0 "hello E907"
will send hello E907 to rpmsg0
msh >eptdev_send 1 "hello E907"
will send hello E907 to rpmsg1

輸入完成后，小核會將信息分別傳入rpmsg0和rpmsg1兩個通訊節點?？梢栽诖蠛薚ina Linux端輸入

cat /dev/rpmsg0
cat /dev/rpmsg1

可查看從E907小核傳輸過來的信息。例如:

root@TinaLinux:~# cat /dev/rpmsg0
hello E907
^C
root@TinaLinux:~# cat /dev/rpmsg1
hello E907
^C

按下Crtl+C結束監聽前持續監聽該節點。

? 您可以在小核端多次傳輸信息到該節點，該節點支持持續接受小核傳輸的信息，例如：

在E907小核，多次傳輸信息到監聽節點rpmsg0

msh >eptdev_send 0 "hello E907 "
will send hello E907  to rpmsg0
msh >eptdev_send 0 "hello E907 "
will send hello E907  to rpmsg0
msh >eptdev_send 0 "hello E907 "
will send hello E907  to rpmsg0
msh >eptdev_send 0 "hello E907 "
will send hello E907  to rpmsg0
msh >eptdev_send 0 "hello E907 "
will send hello E907  to rpmsg0
msh >eptdev_send 0 "hello E907 "
will send hello E907  to rpmsg0
msh >eptdev_send 0 "hello E907 "
will send hello E907  to rpmsg0

在大核端則會一直接收到小核傳輸過來的信息

root@TinaLinux:~# cat /dev/rpmsg0
hello E907 hello E907 hello E907 hello E907 hello E907 hello E907 hello E907 

3.5 關閉通訊

? 在大核Tina Linux端，操作節點即可，輸入以下命令，echo 給到rpmsg的控制關閉節點即可

echo 0 > /sys/class/rpmsg/rpmsg_ctrl0/close
echo 1 > /sys/class/rpmsg/rpmsg_ctrl0/close

例如：

root@TinaLinux:~# echo 0 > /sys/class/rpmsg/rpmsg_ctrl0/close
[ 6783.156899] virtio_rpmsg_bus virtio0: destroying channel sunxi,rpmsg_client addr 0x404
root@TinaLinux:~# echo 1 > /sys/class/rpmsg/rpmsg_ctrl0/close
root@TinaLinux:~# [ 6784.224740] virtio_rpmsg_bus virtio0: destroying channel sunxi,rpmsg_client addr 0x405

? 此時E907小核端也會自動關閉通信節點，自動輸出以下信息

send 0x13131411 to rpmsg0
rpmsg0: unbinding
ctrldev: Rx 44 Bytes
send 0x13131411 to rpmsg1
rpmsg1: unbinding