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.
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.
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.
Tom Soulanille
Damien George
Tony Abboud
Bob Clough
tobbad
Dave Hylands
blmorris