nvs: speed improvement and erase APIs NVS initialization speed issue raised in https://ezredmine.espressif.com/issues/6881 has been addressed for single core mode through optimization of `spi_flash_*` routines. This MR addresses same issue for dual core mode. - An index table is added at Page level, it allows doing fast search of item index based on key name and namespace. This heavily reduces the number of flash reads. - Write operations are batched when writing/erasing long variable-length values (str and blob). This gives a 33% reduction in the number of writes for a 64-byte value, 50% reduction for a 96-byte value. - Add optional (configurable via menuconfig) perfomance counters for spi_flash APIs With these changes, total init time for NVS goes down from 2 seconds to 140 ms. Additional RAM usage is 128-640 bytes per page, depending on content. Typical RAM usage for current use case (storing wifi configuration parameters) is 256 bytes. This change also exposes APIs to erase single key or the whole namespaces, needed for https://ezredmine.espressif.com/issues/6769. See merge request !105 |
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components | ||
docs | ||
examples/04_ble_adv | ||
make | ||
tools | ||
.gitignore | ||
.gitlab-ci.yml | ||
.gitmodules | ||
add_path.sh | ||
Kconfig | ||
LICENSE | ||
README.md |
Using Espressif IoT Development Framework with the ESP32
Prerequisites
Configuring your project
make menuconfig
Compiling your project
make all
... will compile app, bootloader and generate a partition table based on the config.
Flashing your project
When make all
finishes, it will print a command line to use esptool.py to flash the chip. However you can also do this from make by running:
make flash
This will flash the entire project (app, bootloader and partition table) to a new chip. The settings for serial port flashing can be configured with make menuconfig
.
You don't need to run make all
before running make flash
, make flash
will automatically rebuild anything which needs it.
Compiling & Flashing Just the App
After the initial flash, you may just want to build and flash just your app, not the bootloader and partition table:
make app
- build just the app.make app-flash
- flash just the app.
make app-flash
will automatically rebuild the app if it needs it.
(There's no downside to reflashing the bootloader and partition table each time, if they haven't changed.)
The Partition Table
Once you've compiled your project, the "build" directory will contain a binary file with a name like "my_app.bin". This is an ESP32 image binary that can be loaded by the bootloader.
A single ESP32's flash can contain multiple apps, as well as many different kinds of data (calibration data, filesystems, parameter storage, etc). For this reason a partition table is flashed to offset 0x4000 in the flash.
Each entry in the partition table has a name (label), type (app, data, or something else), subtype and the offset in flash where the partition is loaded.
The simplest way to use the partition table is to make menuconfig
and choose one of the simple predefined partition tables:
- "Single factory app, no OTA"
- "Factory app, two OTA definitions"
In both cases the factory app is flashed at offset 0x10000. If you make partition_table
then it will print a summary of the partition table.
For more details about partition tables and how to create custom variations, view the docs/partition_tables.rst
file.
Resources
-
The docs directory of the esp-idf repository contains esp-idf documentation.
-
The esp32.com forum is a place to ask questions and find community resources.
-
Check the Issues section on github if you find a bug or have a feature request. Please check existing Issues before opening a new one.