The Simple Boot feature for Espressif chips is a method of booting
that doesn't depend on a 2nd stage bootloader. Its not the
intention to replace a 2nd stage bootloader such as MCUboot and
ESP-IDF bootloader, but to have a minimal and straight-forward way
of booting, and also simplify the building.
This commit also removes deprecated code and makes this bootloader
configuration as default for esp32 targets and removes the need
for running 'make bootloader' command for it.
Signed-off-by: Almir Okato <almir.okato@espressif.com>
This commit provides an interface to register ISRs that run from
IRAM and keeps track of the non-IRAM interrupts. It enables, for
instance, to avoid disabling all the interrupts during a SPI flash
operation: IRAM-enabled ISRs are, then, able to run during these
operations.
It also makes the code look more similar to the ESP32-S3 SPI flash
implementation by creating a common `esp32_spiflash_init` that is
responsible to create the SPI flash operation tasks. The function
intended to initialize the SPI flash partions was, then, renamed to
`board_spiflash_init`.
