SWD flashing using ST Link v2

Problem:

dpavlin@blue:/blue-zfs/STM32/FST-01/gnuk/tool$ ./stlinkv2.py -s
ST-Link/V2 version info: 2 17 4
Change ST-Link/V2 mode 0002 -> 0001
CORE: 0de01477, CHIP_ID: 00000000
Flash ROM read protection: off
Option bytes: 00000000
Core does not halt, try API V2 halt.
ValueError('Status of core is not halt.', 128)

after several re-runs:

dpavlin@blue:/blue-zfs/STM32/FST-01/gnuk/tool$ ./stlinkv2.py -s
ST-Link/V2 version info: 2 17 4
Change ST-Link/V2 mode 0002 -> 0001
CORE: 1ba01477, CHIP_ID: a0036410
Flash ROM read protection: off
Option bytes: a0036410
Core does not halt, try API V2 halt.
ValueError('Status of core is not halt.', 128)

after a bit of fiddling with cables (it's always cables, right?)

dpavlin@blue:/blue-zfs/STM32/FST-01/gnuk$ sudo ./tool/stlinkv2.py -s
ST-Link/V2 version info: 2 17 4
Change ST-Link/V2 mode 0002 -> 0001
CORE: 1ba01477, CHIP_ID: 20036410
Flash ROM read protection: ON
Option bytes: 03fffffe
The MCU is now stopped.
SUCCESS

dpavlin@blue:/blue-zfs/STM32/FST-01/gnuk$ sudo ./tool/stlinkv2.py -u
ST-Link/V2 version info: 2 17 4
Change ST-Link/V2 mode 0002 -> 0001
Status is 0081
CORE: 1ba01477, CHIP_ID: 20036410
Flash ROM read protection: ON
Option bytes: 03fffffe
Flash ROM read protection disabled.  Reset the board, now.
SUCCESS

# plugin, plugout st-link/v2

dpavlin@blue:/blue-zfs/STM32/FST-01/gnuk$ sudo ./tool/stlinkv2.py -s
ST-Link/V2 version info: 2 17 4
Change ST-Link/V2 mode 0100 -> 0001
CORE: 1ba01477, CHIP_ID: 20036410
Flash ROM read protection: off
Option bytes: ffff5aa5
Flash ROM blank check: True
SUCCESS

dpavlin@blue:/blue-zfs/STM32/FST-01/gnuk$ sudo ./tool/stlinkv2.py -b ../binaries/gnuk/gnuk.bin 
ST-Link/V2 version info: 2 17 4
Change ST-Link/V2 mode 0001 -> 0001
CORE: 1ba01477, CHIP_ID: 20036410
Flash ROM read protection: off
Option bytes: ffff5aa5
Flash ROM blank check: True
SPI Flash ROM ID: bf254a
WRITE
VERIFY
PROTECT
Flash ROM read protection enabled.  Reset the board to enable protection.
SUCCESS

# power cycle

dpavlin@blue:/blue-zfs/STM32/FST-01/gnuk$ sudo ./tool/stlinkv2.py -s
ST-Link/V2 version info: 2 17 4
Change ST-Link/V2 mode 0100 -> 0001
CORE: 1ba01477, CHIP_ID: 20036410
Flash ROM read protection: ON
Option bytes: 03fffffe
The MCU is now stopped.
SUCCESS