Version 2 Partition Table

This version introduces significant improvements over v1 by adding an assets partition to support network-loadable content and optimizing partition layouts for different flash sizes.

Key Changes from v1

Major Improvements

1. Added Assets Partition: New assets partition for network-loadable content
2. Replaced Model Partition: The old model partition (960KB) is replaced with a larger assets partition
3. Optimized App Partitions: Reduced application partition sizes to accommodate assets
4. Enhanced Flexibility: Support for dynamic content updates without reflashing

Assets Partition Features

The assets partition stores:

• Wake word models: Customizable wake word models that can be loaded from the network
• Theme files: Complete theming system including:
  • Fonts (text and icon fonts)
  • Audio effects and sound files
  • Background images and UI elements
  • Custom emoji packs
  • Language configuration files
• Dynamic Content: All content can be updated over-the-air via HTTP downloads

Partition Layout Comparison

v1 Layout (16MB)

• nvs: 16KB (non-volatile storage)
• otadata: 8KB (OTA data)
• phy_init: 4KB (PHY initialization data)
• model: 960KB (model storage - fixed content)
• ota_0: 6MB (application partition 0)
• ota_1: 6MB (application partition 1)

v2 Layout (16MB)

• nvs: 16KB (non-volatile storage)
• otadata: 8KB (OTA data)
• phy_init: 4KB (PHY initialization data)
• ota_0: 4MB (application partition 0)
• ota_1: 4MB (application partition 1)
• assets: 8MB (network-loadable assets)

Available Configurations

8MB Flash Devices (8m.csv)

• nvs: 16KB
• otadata: 8KB
• phy_init: 4KB
• ota_0: 3MB
• ota_1: 3MB
• assets: 2MB

16MB Flash Devices (16m.csv) - Standard

• nvs: 16KB
• otadata: 8KB
• phy_init: 4KB
• ota_0: 4MB
• ota_1: 4MB
• assets: 8MB

16MB Flash Devices (16m_c3.csv) - ESP32-C3 Optimized

• nvs: 16KB
• otadata: 8KB
• phy_init: 4KB
• ota_0: 4MB
• ota_1: 4MB
• assets: 4MB (4000K - limited by available mmap pages)

32MB Flash Devices (32m.csv)

• nvsfactory: 200KB
• nvs: 840KB
• otadata: 8KB
• phy_init: 4KB
• ota_0: 4MB
• ota_1: 4MB
• assets: 16MB

Benefits

1. Dynamic Content Management: Users can download and update wake word models, themes, and other assets without reflashing the device
2. Reduced App Size: Application partitions are optimized, allowing more space for dynamic content
3. Enhanced Customization: Support for custom themes, wake words, and language packs enhances user experience
4. Network Flexibility: Assets can be updated independently of the main application firmware
5. Better Resource Utilization: Efficient use of flash memory with configurable asset storage
6. OTA Asset Updates: Assets can be updated over-the-air via HTTP downloads

Technical Details

• Partition Type: Assets partition uses spiffs subtype for SPIFFS filesystem compatibility
• Memory Mapping: Assets are memory-mapped for efficient access during runtime
• Checksum Validation: Built-in integrity checking ensures asset data validity
• Progressive Download: Assets can be downloaded progressively with progress tracking
• Fallback Support: Graceful fallback to default assets if network updates fail

Migration from v1

When upgrading from v1 to v2:

1. Backup Important Data: Ensure any important data in the old model partition is backed up
2. Flash New Partition Table: Use the appropriate v2 partition table for your flash size
3. Download Assets: The device will automatically download required assets on first boot
4. Verify Functionality: Ensure all features work correctly with the new partition layout

Usage Notes

• The assets partition size varies by configuration to optimize for different flash sizes
• ESP32-C3 devices use a smaller assets partition (4MB) due to limited available mmap pages in the system
• 32MB devices get the largest assets partition (16MB) for maximum content storage
• All partition tables maintain proper alignment for optimal flash performance