RT-Thread/rt-thread: https://github.com/RT-Thread/rt-thread.git @ e16591ced199abffe37ae17477a399ed306c8fb4

tükrözi: https://github-proxy.rt-thread.io/RT-Thread/rt-thread.git

Ihavedone 0fdf20cf58 添加虚拟串口接收缓存的 ENV 配置项，可手动配置接收缓存大小，默认为128字节		6 éve
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class	0fdf20cf58 添加虚拟串口接收缓存的 ENV 配置项，可手动配置接收缓存大小，默认为128字节	6 éve
core	cde81a296d [usbd] Fixed an error where change the interface did not call handler.\|修正了改变接口不调用回调的问题	6 éve
SConscript	98b1956937 [usbd] Add usb audio class.	6 éve