ESP-IDF Adv. - Assign. 4.1

To perform OTA, we need a partition table with at least two partitions.

Assignment steps

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In this first assignment, we will:

1. Check the current partition table loaded in your module
2. Change it to a different default partition table
3. Check the new partition table

Check the current partiton table

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To check the current partition table you need to

1. Read the flash and dump the partition table in a .bin file
2. Convert the .bin file to a readable format

Read the flash

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To read the flash we can use esptool.py:

esptool.py -p <YOUR-PORT> read_flash 0x8000 0x1000 partition_table.bin

where <YOUR-PORT> is the same port you use to flash the device (e.g. /dev/tty.usbmodem1131101 or COM25).

This creates a partition_table.bin file.

Convert the partition table

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To convert it to a readable format, we can use gen_esp32part.py.

python $IDF_PATH/components/partition_table/gen_esp32part.py partition_table.bin

You should get this output:

Parsing binary partition input...
Verifying table...
# ESP-IDF Partition Table
# Name, Type, SubType, Offset, Size, Flags
nvs,data,nvs,0x9000,24K,
phy_init,data,phy,0xf000,4K,
factory,app,factory,0x10000,1M,
coredump,data,coredump,0x110000,64K,

Change partition table

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Now we change the partition table, using the most appropriate default option selectable via menuconfig.

• Open menuconfig: > ESP-IDF: SDK Configuration Editor (menuconfig)
  → Partition Table → Factory app, two OTA definitions

Since we’re now using two OTAs, the default flash configuration of 2MB is not enough, so we need to change it too

• Open menuconfig: > ESP-IDF: SDK Configuration Editor (menuconfig)
  → Serial Flasher Config → Flash Size → 4MB

Check the new partition table

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Let’s do the same steps as before

• esptool.py -p <YOUR-PORT> read_flash 0x8000 0x1000 partition_table.bin
• python $IDF_PATH/components/partition_table/gen_esp32part.py partition_table.bin

And you’ll get

Parsing binary partition input...
Verifying table...
# ESP-IDF Partition Table
# Name, Type, SubType, Offset, Size, Flags
nvs,data,nvs,0x9000,16K,
otadata,data,ota,0xd000,8K,
phy_init,data,phy,0xf000,4K,
factory,app,factory,0x10000,1M,
ota_0,app,ota_0,0x110000,1M,
ota_1,app,ota_1,0x210000,1M,

Conclusion

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In this assignment you changed the partition table from Single factory app, no ota to the default Factory app, two ota definitions. Both of these partition table scheme are provided as default values from ESP-IDF. In the next assignment you will create a custom partition table.

Next step: assignment 4.2