PiKVM - Open and inexpensive DIYIP-KVM on Raspberry Pi

开源项目：https://github.com/pikvm

目的：在 rk3568上实现 pikvm所有功能，本篇主要实现 rk3568 usbGadget （hid，ums）

【资料图】

硬件：

开发板既要当USB OTG口既要当键盘，又要当鼠标使用。则要生成两个hid：，一个键盘hidg0，一个鼠标hidg1。

1. 功能实现

1.1 kernel 配置

在rockchip_linux_defconfig中添加

CONFIG_USB_CONFIGFS_F_HID = yCONFIG_USB_CONFIGFS_MASS_STORAGE=y

./build.sh 编译kernel

./build.sh kernel

确认kernel/drivers/usb/gadget/function/f_hid.c被编译 f_hid.o

烧录固件boot.img 切换到loader模式

1.2 使能HID配置

进入系统后执行

echo usb_hid_en > /tmp/.usb_config & /etc/init.d/S50usbdevice restart

USB功能配置成功会有如下log，表明进入USB Ready:

[ 5662.081549] android_work: sent uevent USB_STATE=CONNECTED[ 5662.085903] configfs-gadget gadget: high-speed config #1: b[ 5662.086881] android_work: sent uevent USB_STATE=CONFIGURED

查看 ls -l /dev/hid*

如果需要添加两个hid，分别做keyboard，mouse

diff --git a/external/rkscript/S50usbdevice b/external/rkscript/S50usbdeviceindex 1162f296f..0ad102150 100644--- a/external/rkscript/S50usbdevice+++ b/external/rkscript/S50usbdevice@@ -64,6 +64,7 @@ function_init()    mkdir ${USB_FUNCTIONS_DIR}/mass_storage.0    mkdir ${USB_FUNCTIONS_DIR}/uvc.gs6    mkdir ${USB_FUNCTIONS_DIR}/hid.usb0+   mkdir ${USB_FUNCTIONS_DIR}/hid.usb1 } configfs_init()@@ -342,11 +343,19 @@ bind_functions()    test $RNDIS_EN = on && syslink_function rndis.gs0    if [ $HID_EN = on ]; then+       # Keyboard        echo 1 > /sys/kernel/config/usb_gadget/rockchip/functions/hid.usb0/protocol        echo 1 > /sys/kernel/config/usb_gadget/rockchip/functions/hid.usb0/subclass        echo 8 > /sys/kernel/config/usb_gadget/rockchip/functions/hid.usb0/report_length        echo -ne x05x01x09x06xa1x01x05x07x19xe0x29xe7x15x00x25x01x75x01x95x08x81x02x95x01x75x08x81x03x95x05x75x01x05x08x19x01x29x05x91x02x95x01x75x03x91x03x95x06x75x08x15x00x25x65x05x07x19x00x29x65x81x00xc0 > /sys/kernel/config/usb_gadget/rockchip/functions/hid.usb0/report_desc        syslink_function hid.usb0+       +       # Mouse +       echo 2 > /sys/kernel/config/usb_gadget/rockchip/functions/hid.usb1/protocol+       echo 1 > /sys/kernel/config/usb_gadget/rockchip/functions/hid.usb1/subclass+       echo 3 > /sys/kernel/config/usb_gadget/rockchip/functions/hid.usb1/report_length+       echo -ne x05x01x09x02xa1x01x09x01xa1x00x05x09x19x01x29x03x15x00x25x01x95x03x75x01x81x02x95x01x75x05x81x03x05x01x09x30x09x31x15x81x25x7fx75x08x95x02x81x06xc0xc0 > /sys/kernel/config/usb_gadget/rockchip/functions/hid.usb1/report_desc+       syslink_function hid.usb1    fi    if [ $UMS_EN = on ];then

改完后需要删除 buildroot/output/rockchip_rk3568，重新编译。

验证功能的话，直接改 buildroot/output/rockchip_rk3568/target/etc/init.d/S50usbdevice

buildroot/output/rockchip_rk3568/target/etc/init.d/.usb_config

usb_adb_enusb_hid_enusb_ums_enums_block=/dev/block/by-name/userdataums_block_auto_mount=on

./build.sh rootfs 烧录即可看到

2. 测试功能

github仓库：https://github.com/aagallag/hid_gadget_test

The HID Gadget driver provides emulation of USB Human InterfaceDevices (HID). The basicHID handling is done in the kernel,and HID reports canbe sent/received through I/O on the/dev/hidgX character devices.

复制hid_gadget_test.c 到sdk，执行

rk3568-sdk/prebuilts/gcc/linux-x86/aarch64/gcc-linaro-6.3.1-2017.05-x86_64_aarch64-linux-gnu/bin/aarch64-linux-gnu-gcc hid_gadget_test.c -o hid_gadget_test -static

生成 hid_gadget_test 使用adb push 到开发板

即可开始测试，输入 g i s t r --left-shift 按下回车将发送数据

3. 开发板介绍

3.1 基本参数

3.2 实物图

3.3 结构图