A board can now define the following to fully customise the extended block
device interface provided by the storage sub-system:
- MICROPY_HW_BDEV_BLOCKSIZE_EXT
- MICROPY_HW_BDEV_READBLOCKS_EXT
- MICROPY_HW_BDEV_WRITEBLOCKS_EXT
- MICROPY_HW_BDEV_ERASEBLOCKS_EXT
Signed-off-by: Damien George <damien@micropython.org>
The pyb.Flash() class can now be used to construct objects which reference
sections of the flash storage, starting at a certain offset and going for a
certain length. Such objects also support the extended block protocol.
The signature for the constructor is: pyb.Flash(start=-1, len=-1).
This new series of MCUs is similar to the L4 series with an additional
Cortex-M0 coprocessor. The firmware for the wireless stack must be managed
separately and MicroPython does not currently interface to it. Supported
features so far include: RTC, UART, USB, internal flash filesystem.
Includes:
- Support for CAN3.
- Support for UART9 and UART10.
- stm32f413xg.ld and stm32f413xh.ld linker scripts.
- stm32f413_af.csv alternate function mapping.
- startup_stm32f413xx.s because F413 has different interrupt vector table.
- Memory configuration with: 240K filesystem, 240K heap, 16K stack.
This part is functionally similar to STM32F767xx (they share a datasheet)
so support is generally comparable. When adding board support the
stm32f767_af.csv and stm32f767.ld should be used.
The flash-IRQ handler is used to flush the storage cache, ie write
outstanding block data from RAM to flash. This is triggered by a timeout,
or by a direct call to flush all storage caches.
Prior to this commit, a timeout could trigger the cache flushing to occur
during the execution of a read/write to external SPI flash storage. In
such a case the storage subsystem would break down.
SPI storage transfers are already protected against USB IRQs, so by
changing the priority of the flash IRQ to that of the USB IRQ (what is
done in this commit) the SPI transfers can be protected against any
timeouts triggering a cache flush (the cache flush would be postponed until
after the transfer finished, but note that in the case of SPI writes the
timeout is rescheduled after the transfer finishes).
The handling of internal flash sync'ing needs to be changed to directly
call flash_bdev_irq_handler() sync may be called with the IRQ priority
already raised (eg when called from a USB MSC IRQ handler).
The code was dereferencing 0x800 and loading a value from there, trying to
use a literal value (not address) defined in the linker script
(_ram_fs_cache_block_size) which was 0x800.
Explicitly writing out the implementation of sys_tick_has_passed makes
these bdev files independent of systick.c and more reusable as a general
component. It also reduces the code size slightly.
The irq.h header is added to spibdev.c because it uses declarations in that
file (irq.h is usually included implicitly via mphalport.h but not always).
This config variable controls whether to support storage on the internal
flash of the MCU. It is enabled by default and should be explicitly
disabled by boards that don't want internal flash storage.
It makes it cleaner, and simpler to support multiple different block
devices. It also allows to easily extend a given block device with new
ioctl operations.
Prior to this patch, storage.c was a combination of code that handled
either internal flash or external SPI flash and exposed one of them as a
block device for the local storage. It was also exposed to the USB MSC.
This patch splits out the flash and SPI code to separate files, which each
provide a general block-device interface (at the C level). Then storage.c
just picks one of them to use as the local storage medium. The aim of this
factoring is to allow to add new block devices in the future and allow for
easier configurability.
Damien George