Using `sectoins.ld.in` instead of a static `sections.ld`, from which the actual used `sections.ld` is generated with the C preprocessor, allows to use the configuration in `sdkconfig.h` as well as Kconfig to use a custom section layout.
Using the vendor `memory.ld.in` instead of a static `memory.ld`, from which the actual used `memory.ld` is generated with the C preprocessor, allows to use the configuration in `sdkconfig.h` as well as Kconfig to use a custom memory layout. For example, it is no longer necessary to maintain different `memory.ld` files for the ESP32 BLE module, since the memory layout is now defined from the values of the configuration.
Add the linker script for ESP32-S3 and modify the ESP32-C3 linker scripts to be compatible with them. The goal is to use a section list of objects that is common for all ESP32x SoCs in future.
The IRAM is much faster, while the IROM is much slower and can only be accessed via a cache, which is also sometimes disabled, e.g. by the WiFi module or when writing to the flash. Therefore, time-critical code as well as code that has to work even when the cache is disabled must be placed in the IRAM.
During the write access to the SPI flash, the IROM cache is not available and only code from the IRAM can be executed. Therefore, the code of file system implementations which access the SPI flash must reside in IRAM.
ESP32 nodes can crash during SPI Flash write operations if required parts of the code are not in the IRAM but in the cached SPI Flash memory, which is disabled during the SPI Flash write operations. Therefore, the code of the SPIFFS package and the VFS module are now stored in the IRAM.
