This implements OO interface based on existing fsusermount code and with
minimal changes to it, to serve as a proof of concept of OO interface.
Examle of usage:
bdev = RAMFS(48)
uos.VfsFat.mkfs(bdev)
vfs = uos.VfsFat(bdev, "/ramdisk")
f = vfs.open("foo", "w")
f.write("hello!")
f.close()
This patch adds support to fsusermount for multiple block devices
(instead of just one). The maximum allowed is fixed at compile time by
the size of the fs_user_mount array accessed via MP_STATE_PORT, which
in turn is set by MICROPY_FATFS_VOLUMES.
With this patch, stmhal (which is still tightly coupled to fsusermount)
is also modified to support mounting multiple devices And the flash and
SD card are now just two block devices that are mounted at start up if
they exist (and they have special native code to make them more
efficient).
The new block protocol is:
- readblocks(self, n, buf)
- writeblocks(self, n, buf)
- ioctl(self, cmd, arg)
The new ioctl method handles the old sync and count methods, as well as
a new "get sector size" method.
The old protocol is still supported, and used if the device doesn't have
the ioctl method.
Per the previously discussed plan. mount() still stays backward-compatible,
and new mkfs() is rought and takes more args than needed. But is a step
in a forward direction.
