bootloader: add OP_HARDWARE api endpoint

This will allow the bbapp to flash different FW versions, depending
on the PCB variants. The initial implementation will respond with a
single byte that identifies the Secure Chip: 0 for ATECC, 1 for Optiga.

py/bitbox02/bitbox02/bitbox02/bootloader.py

@@ -94,6 +94,15 @@ def versions(self) -> typing.Tuple[int, int]:
         firmware_v, signing_pubkeys_v = struct.unpack("<II", response[:8])
         return firmware_v, signing_pubkeys_v
 
+    def hardware(self) -> str:
+        """
+        Returns (Hardware variant).
+        """
+        response = self._query(b"W")
+        if response[:1] == b"\x00":
+            return "ATECC"
+        return "Optiga"
+
     def get_hashes(
         self, display_firmware_hash: bool = False, display_signing_keydata_hash: bool = False
     ) -> typing.Tuple[bytes, bytes]:

py/send_message.py

@@ -1482,6 +1482,10 @@ def _get_versions(self) -> None:
             version = self._device.versions()
             print(f"Firmware version: {version[0]}, Pubkeys version: {version[1]}")
 
+    def _get_hardware(self) -> None:
+        hw = self._device.hardware()
+        print(f"Hardware variant: {hw}")
+
     def _erase(self) -> None:
         self._device.erase()
 
@@ -1506,6 +1510,7 @@ def _menu(self) -> None:
         choices = (
             ("Boot", self._boot),
             ("Print versions", self._get_versions),
+            ("Print hardware variant", self._get_hardware),
             ("Erase firmware", self._erase),
             ("Show firmware hash at startup", self._show_fw_hash),
             ("Don't show firmware hash at startup", self._dont_show_fw_hash),

src/bootloader/bootloader.c

@@ -67,6 +67,8 @@
 #define OP_SCREEN_ROTATE ((uint8_t)'f') /* 0x66 */
 // OP_SET_SHOW_FIRMWARE_HASH - Enable or disable the flag to automatically show the firmware hash.
 #define OP_SET_SHOW_FIRMWARE_HASH ((uint8_t)'H') /* 0x4A */
+// OP_HARDWARE - Return the secure chip variant.
+#define OP_HARDWARE ((uint8_t)'W') /* 0x57 */
 
 // API return codes
 #define OP_STATUS_OK ((uint8_t)0)
@@ -766,6 +768,16 @@ static size_t _api_screen_rotate(uint8_t* output)
     return _report_status(OP_STATUS_OK, output);
 }
 
+static size_t _api_hardware(uint8_t* output)
+{
+    uint8_t type = 0;
+    if (memory_get_securechip_type() == MEMORY_SECURECHIP_TYPE_OPTIGA) {
+        type = 1;
+    }
+    memcpy(output + BOOT_OP_LEN, &type, 1);
+    return BOOT_OP_LEN + 1;
+}
+
 static size_t _api_command(const uint8_t* input, uint8_t* output, const size_t max_out_len)
 {
     memset(output, 0, max_out_len);
@@ -809,6 +821,9 @@ static size_t _api_command(const uint8_t* input, uint8_t* output, const size_t m
     case OP_SCREEN_ROTATE:
         len = _api_screen_rotate(output);
         break;
+    case OP_HARDWARE:
+        len = _api_hardware(output);
+        break;
     default:
         len = _report_status(OP_STATUS_ERR_INVALID_CMD, output);
         _loading_ready = false;