sample visualize-storage output, doc on dumping storage

README.md

@@ -36,5 +36,86 @@ this would suffice for a working invocation (note: you do not need to compile th
 memory.bin
 ```
 
-In the future we will look into publishing complete packages that include the compiled `_pb2.py` files, so that you
-don't need to provide them yourself.
+(In the future we will look into publishing complete packages that include the compiled `_pb2.py` files, so that you
+don't need to provide them yourself.)
+
+Sample output:
+
+```
+% visualize-storage --proto-files-path=~/proj/GP2040-CE/proto --proto-files-path=~/proj/GP2040-CE/lib/nanopb/generator/proto ~/proj/GP2040-CE/BETTER-fn+4way+SMW+demo-memory.bin
+boardVersion: "v0.7.2"
+gamepadOptions {
+  inputMode: INPUT_MODE_HID
+  dpadMode: DPAD_MODE_DIGITAL
+  socdMode: SOCD_MODE_SECOND_INPUT_PRIORITY
+  invertXAxis: false
+  invertYAxis: false
+  switchTpShareForDs4: true
+  lockHotkeys: false
+}
+hotkeyOptions {
+  hotkeyF1Up {
+    dpadMask: 1
+    action: HOTKEY_SOCD_UP_PRIORITY
+  }
+  hotkeyF1Down {
+    dpadMask: 2
+    action: HOTKEY_SOCD_NEUTRAL
+  }
+  ...[and so on]...
+}
+pinMappings {
+  pinDpadUp: 19
+  pinDpadDown: 18
+  pinDpadLeft: 16
+  pinDpadRight: 17
+  pinButtonB1: 8
+  pinButtonB2: 7
+  pinButtonB3: 12
+  pinButtonB4: 11
+  pinButtonL1: 9
+  pinButtonR1: 10
+  pinButtonL2: 5
+  pinButtonR2: 6
+  pinButtonS1: 15
+  pinButtonS2: 13
+  pinButtonL3: 21
+  pinButtonR3: 22
+  pinButtonA1: 14
+  pinButtonA2: 20
+}
+...[and so on]...
+addonOptions {
+  bootselButtonOptions {
+    enabled: false
+    buttonMap: 0
+  }
+  ...[and so on]...
+  dualDirectionalOptions {
+    enabled: true
+    upPin: 23
+    downPin: 27
+    leftPin: 26
+    rightPin: 24
+    dpadMode: DPAD_MODE_DIGITAL
+    combineMode: 3
+  }
+  ...[and so on]...
+}
+forcedSetupOptions {
+  mode: FORCED_SETUP_MODE_OFF
+}
+```
+
+### Dumping the storage section
+
+The storage section of a GP2040-CE board starts at `0x101FE000`. A current limitation of the **visualize-storage** tool
+is that it can only read the Protobuf serialized data, not the footer that is also used as part of the storage engine.
+As such, currently, the binary is expected to be truncated slightly. This will be improved to read the storage footer in
+the near future, but for now, know your `picotool` invocation will be slightly different.
+
+To dump your board's storage:
+
+```
+% picotool save -r 101FE000 101FFFF4 memory.bin
+```