fl16: Implement BIOS mode

When enabled, overrides whatever keyboard layout and always makes the
keys in the physical location of F2, F10 and F12 send the keycodes for
F2/F10/F12.
BIOS is supposed to enable this right after USB enumeration, so that the
BIOS hot keys always work, even if FN-lock is enabled or the user has
remapped their keyboard.
BIOS mode is exited either by the keyboard resetting or by sending the
disable message.

How to send:

1. Find USB devices with Framework VID 0x32AC
2. Filter by interface number == 0x01 and usage page == 0xFF60
3. Set HID report with the following body:

Enable:  0x00 0x0B 0x05 0x01 0xFE 0xFE ... pad the 32 byte buffer with 0xFE
Disable: 0x00 0x0B 0x05 0x00 0xFE 0xFE ... pad the 32 byte buffer with 0xFE
Where the first byte is the report ID 0x00

TODO:

- [ ] Test on ANSI keyboard
- [x] Test on ISO keyboard
- [ ] Test on JIS keyboard
- [ ] Add method to get current status

Signed-off-by: Daniel Schaefer <dhs@frame.work>

keyboards/framework/factory.c

@@ -15,6 +15,7 @@
 enum factory_commands {
     f_emu_keypress  = 0x01, // Next byte is keycode
     f_serialnum     = 0x04, // Read device serial number
+    f_bios_mode     = 0x05, // Read device serial number
     f_bootloader    = 0xFE,
 };
 
@@ -61,6 +62,12 @@ void handle_factory_command(uint8_t *data) {
             uprintf("Serial number unavailable\n");
 #endif
             break;
+        case f_bios_mode:
+            if (command_data[0] == 0x01)
+                bios_mode = true;
+            else
+                bios_mode = false;
+            break;
         default:
             uprintf("Unknown factory command: %u\n", factory_command_id);
             break;

keyboards/framework/framework.c

@@ -59,9 +59,50 @@ void suspend_wakeup_init_kb(void) {
 #endif
 }
 
+// If in BIOS mode, no matter what the keys have been remapped to, always send them as the F keys
+bool bios_mode = false;
+bool handle_bios_hotkeys(uint16_t keycode, keyrecord_t *record) {
+  // Not in bios mode, no special handling, handle as normal
+  if (!bios_mode)
+    return true;
+
+  if (record->event.key.col == 5 && record->event.key.row == 2) {
+      if (record->event.pressed) {
+        register_code(KC_F2);
+      } else {
+        unregister_code(KC_F2);
+      }
+      return false;
+  }
+
+  if (record->event.key.col == 8 && record->event.key.row == 4) {
+      if (record->event.pressed) {
+        register_code(KC_F10);
+      } else {
+        unregister_code(KC_F10);
+      }
+      return false;
+  }
+
+  if (record->event.key.col == 13 && record->event.key.row == 3) {
+      if (record->event.pressed) {
+        register_code(KC_F12);
+      } else {
+        unregister_code(KC_F12);
+      }
+      return false;
+  }
+
+  return true;
+}
+
 bool process_record_kb(uint16_t keycode, keyrecord_t *record) {
   process_record_user(keycode, record);
 
+  if (!handle_bios_hotkeys(keycode, record)) {
+    return false;
+  }
+
 #ifdef RGB_MATRIX_ENABLE
   uint8_t h;
   uint8_t s;

keyboards/framework/framework.h

@@ -23,6 +23,8 @@ enum framework_keycodes {
   FN_LOCK,
 };
 
+extern bool bios_mode;
+
 #define SLEEP_GPIO GP0
 #define MUX_ENABLE_GPIO GP4
 #define BOOT_DONE_GPIO GP5