This is a start to make a more consistent machine.RTC class across ports.
The stm32 pyb.RTC class at least has the datetime() method which behaves
the same as esp8266 and esp32, and with this patch the ntptime.py script
now works with stm32.
If both FS and HS USB peripherals are enabled for a board then the active
one used for the REPL will now be auto-detected, by checking to see if both
the DP and DM lines are actively pulled low. By default the code falls
back to use MICROPY_HW_USB_MAIN_DEV if nothing can be detected.
When going out of memory-mapped mode to do a control transfer to the QSPI
flash, the MPU settings must be changed to forbid access to the memory
mapped region. And any ongoing transfer (eg memory mapped continuous read)
must be aborted.
The Cortex-M7 CPU will do speculative loads from any memory location that
is not explicitly forbidden. This includes the QSPI memory-mapped region
starting at 0x90000000 and with size 256MiB. Speculative loads to this
QSPI region may 1) interfere with the QSPI peripheral registers (eg the
address register) if the QSPI is not in memory-mapped mode; 2) attempt to
access data outside the configured size of the QSPI flash when it is in
memory-mapped mode. Both of these scenarios will lead to issues with the
QSPI peripheral (eg Cortex bus lock up in scenario 2).
To prevent such speculative loads from interfering with the peripheral the
MPU is configured in this commit to restrict access to the QSPI mapped
region: when not memory mapped the entire region is forbidden; when memory
mapped only accesses to the valid flash size are permitted.
Commit 9e68eec8ea introduced a regression
where the PID of the USB device would be 0xffff if the default value was
used. This commit fixes that by using a signed int type.
Entering a bootloader (ST system bootloader, or custom mboot) from software
by directly branching to it is not reliable, and the reliability of it
working can depend on the peripherals that were enabled by the application
code. It's also not possible to branch to a bootloader if the WDT is
enabled (unless the bootloader has specific provisions to feed the WDT).
This patch changes the way a bootloader is entered from software by first
doing a complete system reset, then branching to the desired bootloader
early on in the start-up process. The top two words of RAM (of the stack)
are reserved to store flags indicating that the bootloader should be
entered after a reset.
Previously the end of the heap was the start (lowest address) of the stack.
With the changes in this commit these addresses are now independent,
allowing a board to place the heap and stack in separate locations.
With this the user can select multiple logical units to expose over USB MSC
at once, eg: pyb.usb_mode('VCP+MSC', msc=(pyb.Flash(), pyb.SDCard())). The
default behaviour is the original behaviour of just one unit at a time.
Eventually these responses could be filled in by a function to make their
contents dynamic, depending on the attached logical units. But for now
they are fixed, and this patch fixes the MODE SENSE(6) responses so it is
the correct length with the correct header.
SCSI can support multiple logical units over the one interface (in this
case over USBD MSC) and here the MSC code is reworked to support this
feature. At this point only one LU is used and the behaviour is mostly
unchanged from before, except the INQUIRY result is different (it will
report "Flash" for both flash and SD card).
To use it a board should define MICROPY_PY_USSL=1 and MICROPY_SSL_MBEDTLS=1
at the Makefile level. With the provided configuration it adds about 64k
to the build.
