Changing the Partition Table

R2P2-ESP32 uses a custom partition table, set via sdkconfig.defaults:

CONFIG_PARTITION_TABLE_CUSTOM=y
CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="partitions.csv"

partitions.csv at the project root defines it:

# Name,   Type, SubType, Offset,  Size,    Flags
nvs,      data, nvs,     0x9000,  0x6000,
phy_init, data, phy,     0xf000,  0x1000,
factory,  app,  factory, 0x10000, 2M,
storage,  data, littlefs,       , 1M,

factory — the app partition (2 MB), where your built firmware goes.
storage — a 1 MB LittleFS partition built from the storage/ directory at build time (see File Transfer).
nvs / phy_init — small ESP-IDF system partitions (non-volatile storage, PHY calibration data).

sdkconfig.defaults also sets CONFIG_ESPTOOLPY_FLASHSIZE_4MB=y, so the table above (0x10000 + 2M + 1M ≈ 3.06 MB, comfortably under 4 MB) is sized for a 4 MB flash chip.

Changing it

Edit partitions.csv directly — for example, to grow factory for a larger app, or resize storage for more on-device file space. Keep the total within your chip’s actual flash size, and note that any offset left blank (like storage’s here) is auto-computed to follow the previous partition, so you may need to fill in explicit offsets if you reorder entries. See Espressif’s partition table docs for the full format.

Important: the storage partition’s location and size are also hardcoded on the PicoRuby side, in components/picoruby-esp32/picoruby/mrbgems/picoruby-littlefs/ports/esp32/flash_hal.c — they don’t follow partitions.csv automatically:
#if !defined(LFS_FLASH_TARGET_OFFSET)
  #define LFS_FLASH_TARGET_OFFSET  0x00210000
#endif

#define LFS_FLASH_BLOCK_SIZE   4096  /* == SPI_FLASH_SEC_SIZE */
#define LFS_FLASH_BLOCK_COUNT  256   /* 1 MB */
If changing partitions.csv moves storage to a different offset (e.g. because you grew factory, or reordered entries), update LFS_FLASH_TARGET_OFFSET here to match. If you resize storage itself, update LFS_FLASH_BLOCK_COUNT too (block_count × 4096 bytes). Mismatch either one and littlefs reads/writes the wrong flash region.

After changing it, a full rebuild and reflash is needed — and if you resize storage, treat it like a fresh device (see the flashing note in File Transfer).