circuitpython/docs/library/pyb.Flash.rst
Jim Mussared c737cde947 docs: Replace ufoo with foo in all docs.
Anywhere a module is mentioned, use its "non-u" name for consistency.

The "import module" vs "import umodule" is something of a FAQ, and this
commit intends to help clear that up.  As a first approximation MicroPython
is Python, and so imports should work the same as Python and use the same
name, to a first approximation.  The u-version of a module is a detail that
can be learned later on, when the user wants to understand more and have
finer control over importing.

Existing Python code should just work, as much as it is possible to do that
within the constraints of embedded systems, and the MicroPython
documentation should match the idiomatic way to write Python code.

With universal weak links for modules (via MICROPY_MODULE_WEAK_LINKS) users
can consistently use "import foo" across all ports (with the exception of
the minimal ports).  And the ability to override/extend via "foo.py"
continues to work well.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
2021-08-13 22:53:29 +10:00

54 lines
1.8 KiB
ReStructuredText

.. currentmodule:: pyb
.. _pyb.Flash:
class Flash -- access to built-in flash storage
===============================================
The Flash class allows direct access to the primary flash device on the pyboard.
In most cases, to store persistent data on the device, you'll want to use a
higher-level abstraction, for example the filesystem via Python's standard file
API, but this interface is useful to :ref:`customise the filesystem
configuration <filesystem>` or implement a low-level storage system for your
application.
Constructors
------------
.. class:: pyb.Flash()
Create and return a block device that represents the flash device presented
to the USB mass storage interface.
It includes a virtual partition table at the start, and the actual flash
starts at block ``0x100``.
This constructor is deprecated and will be removed in a future version of MicroPython.
.. class:: pyb.Flash(*, start=-1, len=-1)
:noindex:
Create and return a block device that accesses the flash at the specified offset. The length defaults to the remaining size of the device.
The *start* and *len* offsets are in bytes, and must be a multiple of the block size (typically 512 for internal flash).
Methods
-------
.. method:: Flash.readblocks(block_num, buf)
Flash.readblocks(block_num, buf, offset)
.. method:: Flash.writeblocks(block_num, buf)
Flash.writeblocks(block_num, buf, offset)
.. method:: Flash.ioctl(cmd, arg)
These methods implement the simple and :ref:`extended
<block-device-interface>` block protocol defined by
:class:`os.AbstractBlockDev`.
Hardware Note
-------------
On boards with external spiflash (e.g. Pyboard D), the MicroPython firmware will
be configured to use that as the primary flash storage. On all other boards, the
internal flash inside the :term:`MCU` will be used.