Configurable with MICROPY_PY_BUILTINS_SLICE_ATTRS.  Disabled by default.

There is an issue sending 1 byte on the SPI bus using DMA, but it only
occurs when the transmit is done for the first time after initialising
the SPI and DMA peripherals.  All other cases (sending 2 or more bytes,
doing send_recv, doing recv first) work okay.  We sidestep this issue by
using polling (not DMA) for all 1 byte transfers.  This is fine because
a 1 byte transfer can't be interrupted and doesn't need the benefits of
DMA (and using polling for this case is more efficient).

Resolves #1456.

Use this to set the global optimisation value when executing the main
script (and all scripts it imports).

Fetch the current usb mode and return a string representation when
pyb.usb_mode() is called with no args. The possible string values are interned
as qstr's. None will be returned if an incorrect mode is set.

This needs to land afte #1407 lands, since #1407 is where
the CMSIS_MCU was defined.

This causes unnecessary constants to no longer be generated.
Some constants (like UART_BRR) are different between the F4 and F7

This file should be kept up to date with list of hal commits.

The DFU bootloader on the ST32F7 chip changes the clocksource
for various possible boot sources (UART1, UART3, I2C1-3).
This commit resets those clock sources back to their cold
reset values.

USB serial is now working for F7.

Internal file storage is now working for F7.  The flash is laid out a bit
differently to the F4 - 4 x 32K, 1 x 128K with the rest 256K, so the
internal storage is 96K.

Added more pind definitions for STM32F7DISC board.  Made USART1 be the
default HWUART repl.  The STLINK usb connector also looks like a USB
serial port which is attached to USART1 on the STM32F7DISC.

Thanks to Dave Hylands for the patch.

Thanks to Dave Hylands for the patch.

Thanks to Dave Hylands for the patch.

Capability is #if'd off by default.

Thanks to Dave Hylands for the patch.

Extracted GPIO clock enable logic into mp_hal_gpio_clock_enable
and called from anyplace which might need to use GPIO functions
on ports other than A-D.

Thanks to Dave Hylands for the patch.

Thanks to Dave Hylands for the patch.

All files were converted to linux line endings.
All trailing whitespace was removed using:
for f in f7/inc/* f7/src/*; do sed --in-place 's/[[:space:]]\+$//' $f; done
All non-ascii chars in comments were replaced with ascii equivalents or
removed.

Should fix issue #1393.

In particular this fixes a bug where pyb.sync (and os.sync) fail because
they try to sync the user mounted device even if it's not mounted.

Disabled by default.  Adds 108 bytes to Thumb2 arch when enabled.

This allows a user-specified Timer for the triggering of the ADC read,
mirroring the new behaviour of DAC.write_timed.

Addresses issue #1129.

This allows the DAC to use a user-specified Timer for the triggering
(instead of the default Timer(6)), while still supporting original
behaviour.

Addresses issues #1129 and #1388.

This prevented pin_find_af* functions from being able to find some
of the alternate functions in the pin struct