789ce684c9
Before: The cache won't be disabled when XIP on psram. But during flash erasing/programming, read data will be courrupt. When XIP in psram is enabled, the image is not mapped to the cache so usually there will be no flash access. The only way to read from flash is via the driver or use mmap. The driver has protection during erasing, while th mmap region not. Now: Mmap APIs provide a flag to make mmap->unmap region mutually exclusive to flash erase/programming when XIP from psram. SPI Flash write APIs will benefit from this. When the flag is used, no concurrent access to mapped region will happen while writing; otherwise the cache will be disable to avoid data corruption. Most ESP-IDF APIs calls mmap with this flag. As for users calling mmap-like APIs directly, they can choose whether to enable this by a flag. Closes https://github.com/espressif/esp-idf/issues/14897
| Supported Targets | ESP32 | ESP32-C2 | ESP32-C3 | ESP32-C5 | ESP32-C6 | ESP32-C61 | ESP32-H2 | ESP32-H21 | ESP32-H4 | ESP32-S2 | ESP32-S3 | ESP32-S31 |
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RAM loadable app Example
Starts a FreeRTOS task to print "Hello World". The segments of this application are fully linked and run in internal RAM.
(See the README.md file in the upper level 'examples' directory for more information about examples.)
How to use example
Hardware Required
This example should be able to run on any commonly available ESP32 development board.
Configure the project
idf.py menuconfig
This step is optional, the default settings in sdkconfig.defaults are already set to enable the ram_loadable app feature.
CONFIG_APP_BUILD_TYPE_RAM is enable by default so that all programs and data are linked into internal RAM. For more information about CONFIG_APP_BUILD_TYPE_RAM you can refer to the description in menuconfig.
(Enabling APP_BUILD_TYPE_PURE_RAM_APP option IDF will not compile the spi_flash related code into bin, which will save a lot of internal ram space. For esp32 target, limited by its RAM layout, the available RAM space for the app is too small to accommodate this example without this option enabled, so this option is selected by default for esp32 target.)
Build and Load to RAM
Build the project and load it to the chip's internal RAM, then run monitor tool to view serial output:
idf.py set-target {target name}
idf.py build
esptool -p PORT --no-stub load-ram build/ram_loadable_app.bin
idf.py -p PORT monitor --no-reset
(Replace PORT with the name of the serial port to use.)
(To exit the serial monitor, type Ctrl-].)
(For ram_loadable_app, after the chip is reset, it will start from flash by default, so the program will be executed directly after loading to ram. This is the reason why we use --no-reset. Besides, manually opening idf.py monitor will lose part of the log at startup because the serial port cannot be opened in time, so it is recommended to use a separate serial converter to monitor the output of the UART TX pin)
See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.