added RTT example code

.vscode/launch.json

@@ -35,5 +35,19 @@
             "interface": "swd",
             "runToMain": true,
         },
+        {
+            "type": "cortex-debug",
+            "request": "launch",
+            "name": "Debug RTT Log",
+            "servertype": "external",
+            "gdbTarget": "localhost:2331",
+            "cwd": "${workspaceRoot}",
+            "device": "Cortex-M4",
+            "svdFile": "${workspaceFolder}/va416xx/svd/va416xx-base.svd",
+            "preLaunchTask": "rust: cargo build rtt",
+            "executable": "${workspaceFolder}/target/thumbv7em-none-eabihf/debug/examples/rtt-log",
+            "interface": "swd",
+            "runToMain": true,
+        },
     ]
 }

.vscode/tasks.json

@@ -15,6 +15,18 @@
                 "isDefault": true
             }
         },
+        {
+            "label": "rust: cargo build rtt",
+            "type": "shell",
+            "command": "~/.cargo/bin/cargo", // note: full path to the cargo
+            "args": [
+                "build", "-p", "va416xx-hal", "--example", "rtt-log"
+            ],
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            }
+        },
         {
             "label": "rust: cargo build led blinky",
             "type": "shell",

va416xx-hal

@@ -1 +1 @@
-Subproject commit 6eda28c354bd746476674842cc37c255c851d877
+Subproject commit f9b5f99604daa79102e8efefa645989829bfcd51