This function may be called from a UART IRQ, which may interrupt the system
when it is erasing/reading/writing flash. In such a case all code
executing from the IRQ must be in iRAM (because the SPI flash is busy), so
put mp_keyboard_interrupt in iRAM so ctrl-C can be caught during flash
access.
This patch also takes get_fattime out of iRAM and puts it in iROM to make
space for mp_keyboard_interrupt. There's no real need to have get_fattime
in iRAM because it calls other functions in iROM.
Fixes issue #3897.
This patch takes the software SPI implementation from extmod/machine_spi.c
and moves it to a dedicated file in drivers/bus/softspi.c. This allows the
SPI driver to be used independently of the uPy runtime, making it a more
general component.
Recent vendor SDKs ship libs with code in .text section, which previously
was going into .irom0.text. Adjust the linker script to route these
sections back to iROM (follows upstream change).
This is to keep the top-level directory clean, to make it clear what is
core and what is a port, and to allow the repository to grow with new ports
in a sustainable way.