correct calculation of advanced timers
add support for linker script configuration in mcu config script
use linker script configuration for H750 and H730
add single OTG_HS support on H730 via OTG2
make sure complimentary channels get advanced timers
complemntary timers do not require advanced mode
allow custom clockspeeds of 550Mhz
correct debug pins on H730
support custom clockrate of 520Mhz on H730
correct H730 USB end point pins
restructure linker script for STM32H730
allow chibios_hwdef.py to set advanced timer on L431
don't define RAMFUNC on STM32H730
clock tree for STM32H730
create non-cacheable memory area for SDMMC DMA
don't look for RAM_MAP in bootloader with external flash
convert RCOutput to new virtual timer interface
cope with SDC vs SDMMC
use new SPIv3 driver. Correct clocks for SDMMCv2.
add STM32L431 support
port ChibiOS config to version 8
support SPIv3 driver model v2 on H7
use currcore in debug options
use new mmc API
disable speed optimizations in the bootloader to save a little flash
upgrade to halconf v8.4
relax constraints on QSP/flash clock.
add support for disabling QSPI reset in main firmware
this zeros-watchdog was caused by a SPI DMA error on STM32F405:
https://discuss.ardupilot.org/t/crash-with-4-2-0-beta-and-4-3-0-daily-bdshot/83297
we had incorrectly left these internal errors enabled when asserts
were not enabled. That led to a osalSysHalt()
without these we get an spi_fail internal error, caught by the
SPIDevice code