boards/arm/ht32f491x3: Add support for the HT32F49163 Starter Kit board

[FelipeMdeO]

Summary

This PR improves the existing HT32F491x3 ESK32 board support.

Changes included:

• enable board bring-up for esk32:nsh
• mount /bin and /proc
• enable hello, ostest, dumpstack, and leds in esk32:nsh
• add HT32F491x3 internal GPIO helpers
• add ESK32 user LED support and register /dev/userleds
• add ESK32 board documentation

Impact

• Is new feature added? Yes
• Impact on user: esk32:nsh now provides /bin, /proc, /dev/userleds, and useful built-in apps
• Impact on build: No global build changes
• Impact on hardware: Yes, ARM/HT32F491x3 ESK32 board support
• Impact on documentation: Yes
• Impact on security: No

Testing

• ./tools/configure.sh -l esk32:nsh
• make -j
• make -C Documentation html

Hardware tested on HT32F49163 Starter Kit:

• NSH boot on USART1
• /bin and /proc mounted
• /dev/userleds registered
• hello, ostest, dumpstack, and leds executed successfully
• LED2, LED3, and LED4 toggled correctly

[FelipeMdeO]

Hello @acassis , @linguini1 , @xiaoxiang781216 , can you give me some tips before open PR officially, please?

[lupyuen]

@FelipeMdeO Can you Rebase with Master Branch to trigger the CI Build? We just fixed the CI Build. Thanks :-)

[acassis]

@FelipeMdeO nice work, please divide this PR in three commits: arch support, board support, documentation

[FelipeMdeO]

@lupyuen , can you review this PR also, please?

[xiaoxiang781216]

please fix:

====================================================================================
Configuration/Tool: esk32/nsh,CONFIG_ARM_TOOLCHAIN_GNU_EABI
2026-03-25 02:01:58
------------------------------------------------------------------------------------
  Cleaning...
  Configuring...
  Disabling CONFIG_ARM_TOOLCHAIN_GNU_EABI
  Enabling CONFIG_ARM_TOOLCHAIN_GNU_EABI
  Building NuttX...
  [1/1] Normalize esk32/nsh
4,7c4,6
< # You can use "make menuconfig" to make any modifications to the installed
< # .config file.
< # You can then do "make savedefconfig" to generate a new defconfig file that
< # includes your modifications.
---
> # You can use "make menuconfig" to make any modifications to the installed .config file.
> # You can then do "make savedefconfig" to generate a new defconfig file that includes your
> # modifications.
13,14d11
< # CONFIG_NSH_DISABLE_IFCONFIG is not set
< # CONFIG_NSH_DISABLE_PS is not set
25d21
< CONFIG_EXAMPLES_LEDS=y
26a23
> CONFIG_EXAMPLES_LEDS=y
30d26
< CONFIG_HT32F491X3_PCLK2_FREQUENCY=150000000
32d27
< CONFIG_HT32F491X3_USART1_SERIALDRIVER=y
50a46
> CONFIG_TASK_NAME_SIZE=0
54,59d49
< CONFIG_TASK_NAME_SIZE=0
< CONFIG_USERLED=y
< CONFIG_USERLED_LOWER=y
< CONFIG_USART1_BAUD=115200
< CONFIG_USART1_BITS=8
< CONFIG_USART1_PARITY=0
62a53,54
> CONFIG_USERLED=y
> CONFIG_USERLED_LOWER=y
Saving the new configuration file
HEAD detached at pull/18573/merge
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
	modified:   boards/arm/ht32f491x3/esk32/configs/nsh/defconfig
```
by ./tools/refresh.sh --silent esk32/nsh @FelipeMdeO 

[simbit18]

Hi @FelipeMdeO I think we need to change the title

boards/arm/ht32f491x3: Add support for the HT32F49163 Starter Kit board

https://www.bestmodulescorp.com/en/esk32-31402.html?srsltid=AfmBOoqVKM-qHVVYK9N7h2s0Mgthe3-KJbZConuKTtdMiuU-q2g0dxVN

This is a new board

[FelipeMdeO]

please fix:

====================================================================================
Configuration/Tool: esk32/nsh,CONFIG_ARM_TOOLCHAIN_GNU_EABI
2026-03-25 02:01:58
------------------------------------------------------------------------------------
  Cleaning...
  Configuring...
  Disabling CONFIG_ARM_TOOLCHAIN_GNU_EABI
  Enabling CONFIG_ARM_TOOLCHAIN_GNU_EABI
  Building NuttX...
  [1/1] Normalize esk32/nsh
4,7c4,6
< # You can use "make menuconfig" to make any modifications to the installed
< # .config file.
< # You can then do "make savedefconfig" to generate a new defconfig file that
< # includes your modifications.
---
> # You can use "make menuconfig" to make any modifications to the installed .config file.
> # You can then do "make savedefconfig" to generate a new defconfig file that includes your
> # modifications.
13,14d11
< # CONFIG_NSH_DISABLE_IFCONFIG is not set
< # CONFIG_NSH_DISABLE_PS is not set
25d21
< CONFIG_EXAMPLES_LEDS=y
26a23
> CONFIG_EXAMPLES_LEDS=y
30d26
< CONFIG_HT32F491X3_PCLK2_FREQUENCY=150000000
32d27
< CONFIG_HT32F491X3_USART1_SERIALDRIVER=y
50a46
> CONFIG_TASK_NAME_SIZE=0
54,59d49
< CONFIG_TASK_NAME_SIZE=0
< CONFIG_USERLED=y
< CONFIG_USERLED_LOWER=y
< CONFIG_USART1_BAUD=115200
< CONFIG_USART1_BITS=8
< CONFIG_USART1_PARITY=0
62a53,54
> CONFIG_USERLED=y
> CONFIG_USERLED_LOWER=y
Saving the new configuration file
HEAD detached at pull/18573/merge
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
	modified:   boards/arm/ht32f491x3/esk32/configs/nsh/defconfig

by ./tools/refresh.sh --silent esk32/nsh @FelipeMdeO

done