- Created new `bluepill-128kib` as 128KiB version of the `bluepill`
- Created new `blackpill-128kib` as 128KiB version of the `blackpill`
- Updated `openocd.cfg` to allow flashing 128KiB of ROM
- Boards using stm32f103xx use the same custom config for xtimer
which relies on the same underlying hardware timers that hang
when sleeping for <20us so spin when approaching that limit.
- Indicated that the hardware reset signal is used to reset the device and that
OpenOCD will that connect under reset
- Added troubleshooting for flashing using hardware reset
- Removed previous troubleshooting for flashing, as this issue is no longer
present since OpenOCD connects under reset
The STM32F103C8 secretly comes with 128KiB flash instead of 64KiB. Still, only
64KiB of it are tested and guaranteed to work. However, most of the times the
whole 128KiB flash works just fine. In the BluePill documentation this fact is
already documented and by using
$ make BOARD=bluepill CPU_MODEL=stm32f103cb
the whole 128 KiB can be used by RIOT. When using this hack routinely, it easier
to use environment variables instead. But allowing to overwrite CPU_MODEL via
environment variables seems to be a bad thing, as it is easy to forget to clear
that environment variable when changing the BOARD variable.
This commit introduces the new STM32F103C8_FLASH_HACK variable, which unlocks
the 128KiB FLASH when set to "1". The BluePill documentation has been updated
accordingly.
