boards/arm64: add RK3588S and Orange Pi 5 Pro support

[emomaxd]

Summary

Add initial NuttX support for the Rockchip RK3588S and Orange Pi 5 Pro.

The port boots through U-Boot, enters NuttX at EL2, switches to EL1 and reaches NSH. It includes the ARM64 boot path, GICv3 setup, the ARM generic timer, a UART2 console with polling transmit, PSCI reset, NSH and OSTest configurations, and board documentation.

The initial MMU setup uses identity mappings, as existing ARM64 ports such as BCM2711 do. Only the required UART2, GIC and DRAM regions are mapped.

The RAM mapping is intentionally limited to a 512 MiB window starting at 0x02080000. This is not a hardware limit. It is a conservative range inside the first DRAM bank reported by U-Boot on the tested 4 GiB board and stays below the U-Boot runtime and FDT locations observed during testing. Reading the firmware-provided memory and reserved-memory ranges from the DTB can be added separately.

DRAM training, UART2 clock and pin setup, and boot media access remain firmware responsibilities. The initial port does not parse the DTB or include peripheral drivers or SMP support.

Impact

This adds a new ARM64 SoC and board. Existing configurations are unchanged.

Testing

Tested on a 4 GiB Orange Pi 5 Pro with an AArch64 bare-metal toolchain.

• Built orangepi-5-pro:nsh with Make and CMake/Ninja, and booted nuttx.bin with U-Boot booti
• Verified UART2 transmit and receive at 1500000 baud
• Reached NSH and checked uname, procfs and memory information
• Verified the ARM generic timer with sleep 5 and /proc/uptime
• Verified PSCI reset with reboot
• Built and ran orangepi-5-pro:ostest; it completed with status 0
• Ran calib_udelay; it reported CONFIG_BOARD_LOOPSPERMSEC=116422 with R-squared 1.0000
• Built the documentation with Sphinx warnings treated as errors
• Ran git diff --check

NSH boot

OSTest

Board

[github-actions]

MemBrowse Memory Report

No memory changes detected for:

• arduino-mega2560
• esp32-devkitc
• hifive1-revb
• mirtoo
• qemu-armv8a
• qemu-intel64
• rx65n-rsk2mb
• s698pm-dkit
• stm32-nucleo-f103rb

[linguini1]

Awesome!

Can you change the commit message topics more in line with:

• boards/arm64/rk3588s:
• docs/boards/orangepi:
  To get more granular for our release notes?

[linguini1]

Exciting port!

[emomaxd]

Thanks! I'm working on docs currently.

[emomaxd]

Thanks for the feedback!

I've updated the docs following the template at board.rst.

Specifically:

• Added a local board image (orangepi-5-pro.png) and scaled it down.
• Included the ./tools/configure.sh commands.
• Added key features, buttons, LEDs, and pin mappings.
• Restructured the RK3588 index to match the BCM2711 page.
• Cleaned up and clarified the U-Boot booting/relocation instructions.

Also reworded the commit topics to boards/arm64/rk3588s: and docs/boards/orangepi: as requested. Pushed the changes, let me know what you think!

@linguini1 @xiaoxiang781216