esp32/boards: Add new board variant for esp32c2 devices with 2MiB flash.

Factors out the space-saving config options from `sdkconfig.d2wd` to a new
`sdkconfig.flash_2MiB` file, and uses that in the new C2 FLASH_2M variant.

Signed-off-by: Florent <[email protected]>

Author: fdlamotte

ports/esp32/boards/ESP32_GENERIC/mpconfigvariant_D2WD.cmake

@@ -1,5 +1,6 @@
 set(SDKCONFIG_DEFAULTS
     ${SDKCONFIG_DEFAULTS}
+    boards/sdkconfig.flash_2MiB
     boards/ESP32_GENERIC/sdkconfig.d2wd
 )
 

ports/esp32/boards/ESP32_GENERIC/sdkconfig.d2wd

@@ -1,17 +1,3 @@
-# Optimise using -Os to reduce size
-CONFIG_COMPILER_OPTIMIZATION_SIZE=y
-CONFIG_COMPILER_OPTIMIZATION_PERF=n
-CONFIG_COMPILER_OPTIMIZATION_CHECKS_SILENT=y
-
-# Change maximum log level to error, to reduce firmware size.
-CONFIG_LOG_MAXIMUM_LEVEL_ERROR=y
-CONFIG_LOG_MAXIMUM_LEVEL_INFO=n
-
-# Disable SPI Ethernet driver to reduce firmware size.
-CONFIG_ETH_USE_SPI_ETHERNET=n
-
+# Setting specific to d2wd
 CONFIG_ESPTOOLPY_FLASHMODE_DIO=y
 CONFIG_ESPTOOLPY_FLASHFREQ_40M=y
-CONFIG_ESPTOOLPY_FLASHSIZE_2MB=y
-CONFIG_PARTITION_TABLE_CUSTOM=y
-CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="partitions-2MiB.csv"

ports/esp32/boards/ESP32_GENERIC_C2/board.json

@@ -18,5 +18,8 @@
     "product": "ESP32-C2",
     "thumbnail": "",
     "url": "https://www.espressif.com/en/products/modules",
+    "variants": {
+        "FLASH_2M": "2MiB flash"
+    },
     "vendor": "Espressif"
 }

ports/esp32/boards/ESP32_GENERIC_C2/board.md

@@ -1,3 +1,5 @@
 The following files are firmware images that should work on most ESP32-C2-based
 boards with at least 4MiB of flash and 26MHz crystal frequency. This includes
 ESP8684-WROOM and ESP8684-MINI modules.
+
+If your board has only 2MiB of flash, you should try the FLASH\_2M variant

ports/esp32/boards/ESP32_GENERIC_C2/mpconfigboard.h

@@ -1,7 +1,12 @@
 // This configuration is for a generic ESP32C2 board with 4MiB (or more) of flash.
 
+#ifndef MICROPY_HW_BOARD_NAME
 #define MICROPY_HW_BOARD_NAME               "ESP32C2 module"
+#endif
+
+#ifndef MICROPY_HW_MCU_NAME
 #define MICROPY_HW_MCU_NAME                 "ESP32C2"
+#endif
 
 #define MICROPY_HW_ENABLE_SDCARD            (0)
 #define MICROPY_PY_MACHINE_I2S              (0)

ports/esp32/boards/ESP32_GENERIC_C2/mpconfigvariant_FLASH_2M.cmake

@@ -0,0 +1,10 @@
+set(SDKCONFIG_DEFAULTS
+    ${SDKCONFIG_DEFAULTS}
+    boards/sdkconfig.flash_2MiB
+)
+
+list(APPEND MICROPY_DEF_BOARD
+    MICROPY_HW_BOARD_NAME="Generic ESP32-C2 module with 2MiB Flash"
+    MICROPY_OPT_COMPUTED_GOTO=0
+    MICROPY_PY_NETWORK_LAN=0
+)

ports/esp32/boards/sdkconfig.flash_2MiB

@@ -0,0 +1,17 @@
+# Set flash size to 2MiB.
+CONFIG_ESPTOOLPY_FLASHSIZE_4MB=n
+CONFIG_ESPTOOLPY_FLASHSIZE_2MB=y
+CONFIG_PARTITION_TABLE_CUSTOM=y
+CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="partitions-2MiB.csv"
+
+# Disable SPI Ethernet driver to reduce firmware size.
+CONFIG_ETH_USE_SPI_ETHERNET=n
+
+# Optimise using -Os to reduce size.
+CONFIG_COMPILER_OPTIMIZATION_SIZE=y
+CONFIG_COMPILER_OPTIMIZATION_PERF=n
+CONFIG_COMPILER_OPTIMIZATION_CHECKS_SILENT=y
+
+# Change maximum log level to error, to reduce firmware size.
+CONFIG_LOG_MAXIMUM_LEVEL_ERROR=y
+CONFIG_LOG_MAXIMUM_LEVEL_INFO=n