refactor: Optimize unnecessary chip interrogations

esptool/cmds.py

@@ -24,7 +24,7 @@ from .loader import (
     ESPLoader,
     timeout_per_mb,
 )
-from .targets import CHIP_DEFS, CHIP_LIST, ESP8266ROM, ROM_LIST
+from .targets import CHIP_DEFS, CHIP_LIST, ROM_LIST
 from .util import (
     FatalError,
     NotImplementedInROMError,
@@ -93,14 +93,10 @@ def detect_chip(
     detect_port.connect(connect_mode, connect_attempts, detecting=True)
     try:
         print("Detecting chip type...", end="")
-        res = detect_port.check_command(
-            "get security info", ESPLoader.ESP_GET_SECURITY_INFO, b""
-        )
-        # 4b flags, 1b flash_crypt_cnt, 7*1b key_purposes, 4b chip_id
-        res = struct.unpack("<IBBBBBBBBI", res[:16])
-        chip_id = res[9]  # 2/4 status bytes invariant
-
-        for cls in ROM_LIST[3:]:
+        chip_id = detect_port.get_chip_id()
+        for cls in [
+            n for n in ROM_LIST if n.CHIP_NAME not in ("ESP8266", "ESP32", "ESP32S2")
+        ]:
             # cmd not supported on ESP8266 and ESP32 + ESP32-S2 doesn't return chip_id
             if chip_id == cls.IMAGE_CHIP_ID:
                 inst = cls(detect_port._port, baud, trace_enabled=trace_enabled)
@@ -831,7 +827,7 @@ def image_info(args):
                     raise FatalError("Append digest field not 0 or 1")
 
                 chip_id = int.from_bytes(extended_header[4:5], "little")
-                for rom in [n for n in ROM_LIST if n != ESP8266ROM]:
+                for rom in [n for n in ROM_LIST if n.CHIP_NAME != "ESP8266"]:
                     if chip_id == rom.IMAGE_CHIP_ID:
                         args.chip = rom.CHIP_NAME
                         break

esptool/loader.py

@@ -871,10 +871,12 @@ class ESPLoader(object):
         self.flash_begin(0, 0)
         self.flash_finish(reboot)
 
-    def flash_id(self):
+    def flash_id(self, _cache=[]):
         """Read SPI flash manufacturer and device id"""
-        SPIFLASH_RDID = 0x9F
-        return self.run_spiflash_command(SPIFLASH_RDID, b"", 24)
+        if not _cache:
+            SPIFLASH_RDID = 0x9F
+            _cache.append(self.run_spiflash_command(SPIFLASH_RDID, b"", 24))
+        return _cache[0]
 
     def flash_type(self):
         """Read flash type bit field from eFuse. Returns 0, 1, None (not present)"""
@@ -893,13 +895,17 @@ class ESPLoader(object):
         }
 
     @esp32s3_or_newer_function_only
-    def get_chip_id(self):
-        res = self.check_command("get security info", self.ESP_GET_SECURITY_INFO, b"")
-        res = struct.unpack(
-            "<IBBBBBBBBI", res[:16]
-        )  # 4b flags, 1b flash_crypt_cnt, 7*1b key_purposes, 4b chip_id
-        chip_id = res[9]  # 2/4 status bytes invariant
-        return chip_id
+    def get_chip_id(self, _cache=[]):
+        if not _cache:
+            res = self.check_command(
+                "get security info", self.ESP_GET_SECURITY_INFO, b""
+            )
+            res = struct.unpack(
+                "<IBBBBBBBBI", res[:16]
+            )  # 4b flags, 1b flash_crypt_cnt, 7*1b key_purposes, 4b chip_id
+            chip_id = res[9]  # 2/4 status bytes invariant
+            _cache.append(chip_id)
+        return _cache[0]
 
     @classmethod
     def parse_flash_size_arg(cls, arg):

esptool/targets/esp32.py

@@ -153,13 +153,10 @@ class ESP32ROM(ESPLoader):
             return 0xF
 
     def get_encrypted_download_disabled(self):
-        if (
+        return (
             self.read_reg(self.EFUSE_DIS_DOWNLOAD_MANUAL_ENCRYPT_REG)
             & self.EFUSE_DIS_DOWNLOAD_MANUAL_ENCRYPT
-        ):
-            return True
-        else:
-            return False
+        )
 
     def get_flash_encryption_enabled(self):
         flash_crypt_cnt = (