OpenWrt NanoPi R2S

Thanks for the contribution of all "OpenWrt NanoPi R2S" crews. Here is my "Non-Official" Translation of the "OpenWrt NanoPi R2S" Announcement.

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From last July till now, we all work together to conquer issues one after another.

Now, we have completed the optimizations for those devices.

# For NanoPI R1S H5:
- we backported lot patches from Kernal Mainline to improve the functions for CPU Dynamic Frequency Adjusting and SOC Temperature Reading.

# For NanoPi R2S:
- we introduced Rockchip DDRLoader to fix the Low Memory Frequency issue (to improve the overall performance);
- backported the patches from Kernal Mailinglisting to fix the soft reboot issue of Rockchip 3288 / 3328 / 3399 series;
- bringed in the USB3 driver from Rockchip BSP kernel to fix the stability issue of USB-Converted Ethernet Port;
- took and tuned the overclock patch from Armbian to improve the performance.

# For NanoPi R4S:
- we introduced the driver of on-chip hardware random number generator to improve some software's performance;
- introduced the U-boot target from FriendltElec to solve the same U-boot cannot be used in models using different memory types;
- refered and re-wrote the overclock patch for rk3399 to improve the performance of NanaPi4 series devices.

For ARMv8 devices (except Broadcom-based):
- we introduce the mbedTLS ARMv8-CE crypto extension to improve AES performace (about 4 to 10 times);
- modules which using this crypto library (such as Shadowsocks) will get huge performance improvement.

We do follow the Open Source License, source code is fully open, WYSIWYG.

The source code is licensed under GPL-3.0-or-later. Please obey the rules when redistributing.

Thanks for the friends from NanoPi R2S / R4S Club, and all crews from Project ImmortalWrt.

Special thanks to some "generous" vendors, the developer now is worth 13 RMB (compare to 7 RMB earlier). Developers are better valued again...

Last, we wish that FriendlyElec and Rockchip can improve their support in the future
(compare to GL. iNet who is voluntary offering the source code;
R1S (which using sunxi SoC) is much less hassle than the Rockchip models.)
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