Open-CMSIS-Pack · ReinhardKeil · Dec 12, 2025 · Dec 10, 2025 · Dec 10, 2025 · Dec 10, 2025
diff --git a/docs/JLink-Debugger.md b/docs/JLink-Debugger.md
@@ -0,0 +1,72 @@
+# Segger J-Link Debugger
+
+!!! Note
+    - This section contains preliminary information and is work-in-progress.
+
+The CMSIS-Toolbox organizes for debuggers projects and configuration options.
+This chapter explains the usage of the [Segger J-Link GDB Server](https://kb.segger.com/J-Link_GDB_Server) in combination with the CMSIS-Toolbox.
+
+- [Extended Options](#extended-options) explains additional configuration features that are required in specific use-cases.
+
+Other manual sections describe how to configure debuggers:
+
+- [Run and Debug Configuration](build-overview.md#run-and-debug-configuration) explains overall structure and how projects and images are configured.
+- [Debugger Configuration - J-Link Server](YML-Input-Format.md#j-link-server) contains details about the options that are specific to J-Link.
+
+## Extended Options
+
+The section [Debugger Configuration - J-Link Server](YML-Input-Format.md#j-link-server) contains the J-Link configuration for typical systems.
+
+### `connect:`
+
+Configures the behavior for connecting J-Link to the hardware target for interactive debug.
+
+`connect:`                                                |             | Description
+:---------------------------------------------------------|-------------|:------------------------------------
+&nbsp;&nbsp;&nbsp; `mode:`                                |**Required** | Selects the connect mode: `attach`, `halt` (default).
+
+Connect Mode  | Description
+:-------------|:--------------------------------------
+`attach`      | Do not change state of the core(s). No reset is executed.
+`halt`        | Halt core(s) after connect.
+
+### `reset:`
+
+Configures the reset behavior for each core when a reset is requested during interactive debug.
+
+`reset:`                                                  |             | Description
+:---------------------------------------------------------|-------------|:------------------------------------
+`- pname:`                                                |  Optional   | Identifies the processor (not requried for single core system).
+&nbsp;&nbsp;&nbsp; `type:`                                |**Required** | Selects the reset type: `hardware`, `system` (default), `core`.
+
+Reset Types   | Description
+:-------------|:--------------------------------------
+`hardware`    | Use the J-Link [`reset pin`](https://kb.segger.com/J-Link_Reset_Strategies#Type_2:_reset_pin) reset mode.
+`system`      | Use the J-Link [`normal`](https://kb.segger.com/J-Link_Reset_Strategies#Type_0:_normal) reset mode.
+`core`        | Use the J-Link [`core`](https://kb.segger.com/J-Link_Reset_Strategies#Type_1:_core) reset mode.
+
+**Examples:**
+
+```yml
+debugger:
+  name: J-Link Server       # default connect, halt and reset behavior
+```
+
+```yml
+debugger:
+  name: J-Link Server
+  connect: attach           # connect without reset and without CPU state change
+  reset:
+    - type: system          # use system reset
+```
+
+```yml
+debugger:
+  name: J-Link Server
+  connect: halt             # halt CPU after connect
+  reset:
+    - pname: Core0          # for Core0
+      type: hardware        # use hardware reset
+    - pname: Core1          # for Core1
+      type: core            # use core reset
+```
diff --git a/docs/YML-Input-Format.md b/docs/YML-Input-Format.md
@@ -2438,7 +2438,7 @@ Debug Adapter `name:`           | Description
 [`<adapter>@Arm-Debugger`](#arm-debugger) | Debug Adapters that interface via the Arm-Debugger.
 [`Arm-FVP`](#arm-fvp)           | [FVP](https://arm-software.github.io/AVH/main/simulation/html/index.html) simulation models that represent processor sub-systems.
 [`Keil uVision`](#keil-uvision) | [uVision Debugger](http://developer.arm.com/documentation/101407/0543/Debugging) that is integrated in the Keil uVision IDE. 
-[`JLink Server`](#jlink-server) | [Segger J-Link](https://www.segger.com/products/debug-probes/j-link/) debug probes that connect using the JLink Server.
+[`J-Link Server`](#j-link-server) | [Segger J-Link](https://www.segger.com/products/debug-probes/j-link/) debug probes that connect using the J-Link Server.
 
 The [Arm CMSIS Solution](https://marketplace.visualstudio.com/items?itemName=Arm.cmsis-csolution) VS Code extension uses the `debugger:` node to create entries in the files `.vscode/tasks.json` and `.vscode/launch.json` for running and debugging using the specified debug adapter. [`pyOCD`](#pyocd) supports a command-line mode that uses the [`*.cbuild-run.yml`](YML-CBuild-Format.md#run-and-debug-management) file which is created by the CMSIS-Toolbox.
 
@@ -2628,50 +2628,58 @@ debugger:
   name: Keil uVision
 ```
 
-### JLink Server
+### J-Link Server
 
-This section lists options that are specific for the  [Segger J-Link](https://www.segger.com/products/debug-probes/j-link/) debug probes.
+This section lists options that are specific for the [Segger J-Link](https://www.segger.com/products/debug-probes/j-link/) debug probes.
 
-#### `debugger:` for JLink Server
+[Extended options](JLink-Debugger.md#extended-options) are required for rare use cases and further tailor the behaviour of J-Link Server.
+
+#### `debugger:` for J-Link Server
 
 debugger:                         |             | Description
 :---------------------------------|:------------|:-----------------------------------------------
 &nbsp;&nbsp;&nbsp; `name:`        |**Required** | Identifies the debug adapter with `<adapter>@pyOCD`.
 &nbsp;&nbsp;&nbsp; `clock:`       |  Optional   | Debug clock speed in Hz.
 &nbsp;&nbsp;&nbsp; `protocol:`    |  Optional   | Debug portocol (jtag or swd).
-&nbsp;&nbsp;&nbsp; [`telnet:`](#telnet-for-jlink-server) |  Optional   | Telnet service configuration.
-&nbsp;&nbsp;&nbsp; [`trace:`](#trace-for-jlink-server)   |  Optional   | Trace configuration.
+&nbsp;&nbsp;&nbsp; [`telnet:`](#telnet-for-j-link-server) |  Optional   | Telnet service configuration.
+&nbsp;&nbsp;&nbsp; [`trace:`](#trace-for-j-link-server)   |  Optional   | Trace configuration.
+&nbsp;&nbsp;&nbsp; [`connect:`](JLink-Debugger.md#connect) |  Optional   | Extended Option: Connect mode to hardware.
+&nbsp;&nbsp;&nbsp; [`reset:`](JLink-Debugger.md#reset)           |  Optional   | Extended Option: Reset type configuration for various cores.
 
 **Examples:**
 
 ```yml
 debugger:
-  name: JLink Server
+  name: J-Link Server
   clock: 4000                    # 4000 kHz
   protocol: swd
 ```
 
-#### `telnet:` for JLink Server
+#### `telnet:` for J-Link Server
 
 !!! Note
     The `telnet:` feature will be implemented until Dec 2025. This section is only a preview.
 
-J-Link supports a Telnet service that connects to character I/O funtions. Character I/O is supported via Semihosting (or Segger RTT channel 0). Currently only semihosting is configured for the primiary core.
+J-Link supports a Telnet service that connects to character I/O funtions. Character I/O is supported via Semihosting (or Segger RTT channel 0). Currently only semihosting is configured for the primary core.
 
 `telnet:`                                                 |             | Description
 :---------------------------------------------------------|-------------|:------------------------------------
-`- mode:`                                                 |**Required** | Redirect output: `server`, `monitor`.
+`- mode:`                                                 |**Required** | Redirect output: `server`, `console`, `monitor`, `off` (default).
+&nbsp;&nbsp;&nbsp; `pname:`                               |  Optional   | Identifies the processor (not requried for single core system).
+&nbsp;&nbsp;&nbsp; `port:`                                |  Optional   | Set TCP/IP port number of Telnet Server (default: 4444, 4445, ... incremented for each processor).
 
 Telnet Mode   | Description
 :-------------|:--------------------------------------
 `server`      | Serial I/O to Telnet server port
 `console`     | Serial output to console (Debug console in VS Code). 
 `monitor`     | Serial I/O via TCP/IP port to VS Code Serial Monitor.
+`off`         | Serial I/O disabled.
 
 !!! Note
-    - When no `telnet` node is applied Serial I/O is disabled.
+    - The Telnet service is always enabled for the J-Link GDB Server. The mode `off` turns off the data source (semihosting, Segger RTT).
+    - When no `telnet` node is added then Serial I/O to all processors is set to mode `off`.
 
-#### `trace:` for JLink Server
+#### `trace:` for J-Link Server
 
 !!! Note
     The `trace:` feature is Work-In-Progress and will be completed in Q1'26.

diff --git a/docs/build-operation.md b/docs/build-operation.md
@@ -383,7 +383,7 @@ debug-adapters:
       protocol: swd
       clock: 10000000
 
-  - name: "JLink Server"
+  - name: "J-Link Server"
     template: jlink.adapter.json              # template file
     defaults:                                 # default values to use when nowhere specified
       port: 3333                              # default value of first gdbserver port
@@ -515,7 +515,7 @@ debug-adapters:
             range: [1, 100000]
             default: 4444
 
-  - name: "JLink Server"
+  - name: "J-Link Server"
       - section: Debug Interface
         description: Interface configuration for the debug port
         options:

diff --git a/docs/build-overview.md b/docs/build-overview.md
@@ -10,7 +10,7 @@ This chapter outlines the structure of *csolution project files* that contain th
 - [Directory Structure](#directory-structure) describes the overall directory structure of projects.
 - [Linker Script Management](#linker-script-management) defines the  available memory and controls the linker operation.
 - [Generator Support](#generator-support) integrates configuration tools such as STM32CubeMX or MCUXpresso Config.
-- [Run and Debug Configuration](#run-and-debug-configuration) explains how to configure debug adapters such as CMSIS-DAP or JLink.
+- [Run and Debug Configuration](#run-and-debug-configuration) explains how to configure debug adapters such as CMSIS-DAP or J-Link.
 - [West Build System Integration](#west-build-system-integration) allows to manage Zephyr applications in context with a *csolution project*.
 
 ## Overview of Operation
@@ -1009,7 +1009,7 @@ solution:
       target-set:
         - set:
           debugger:
-            name: JLink Server
+            name: J-Link Server
             port: 3333
             protocol: swd
           images: