raspberry pi 4 nrf52840 adafruit bootloader speed 500

> reset halt; flash write_image /home/pi/openocd-config/bootloader.hex
target halted due to debug-request, current mode: Thread
xPSR: 0x01000000 pc: 0x00000a80 msp: 0x20000400
nRF52840-xxAA(build code: D0) 1024kB Flash, 256kB RAM
Flash protection of this nRF device is not supported
Padding image section 0 at 0x00000b00 with 1280 bytes
Flash write discontinued at 0x00025de8, next section at 0x000f4000
SWD DPIDR 0x2ba01477
Failed to write memory at 0x20000ef8
Failed to write to nrf5 flash
error writing to flash at address 0x00000000 at offset 0x00000000

> reset halt; flash write_image /home/pi/openocd-config/bootloader.hex
target halted due to debug-request, current mode: Thread
xPSR: 0x01000000 pc: 0x00000a80 msp: 0x20000400
Padding image section 0 at 0x00000b00 with 1280 bytes
Flash write discontinued at 0x00025de8, next section at 0x000f4000
SWD DPIDR 0x2ba01477
Failed to write memory at 0x20000000
JTAG failure 7
SWD DPIDR 0x2ba01477
Failed to write to nrf5 flash
error writing to flash at address 0x00000000 at offset 0x00000000

> reset halt; flash write_image /home/pi/openocd-config/bootloader.hex
target halted due to debug-request, current mode: Thread
xPSR: 0x01000000 pc: 0x00000a80 msp: 0x20000400
Padding image section 0 at 0x00000b00 with 1280 bytes
Flash write discontinued at 0x00025de8, next section at 0x000f4000
SWD DPIDR 0x2ba01477
Failed to write memory at 0x20000f60
JTAG failure 7
SWD DPIDR 0x2ba01477
Failed to write to nrf5 flash
error writing to flash at address 0x00000000 at offset 0x00000000