NIIBE Yutaka gniibe at
Thu May 10 22:41:48 CEST 2018

Tom Li <tomli at> wrote:
> Thanks for your great work! There is little extra time for me in these
> days so I temporaryly stopped the project I mentioned earlier in this
> year, but will continue soon. 

No problem.  Thanks.  Just like your effort, it took some time for me to
figure out the difference of peripherals (USB, ADC, and Flash ROM), but
it was manageable.

Only a single real problem to be fixed is... a tool like OpenOCD.  To
unlock the protection, GD32F103 requires writing 0x5aa5, but for some
reason, "stm32f1x unlock 0" didn't work for me.  I manually did
following to unlock the device:

    mww 0x40022004 0x45670123
    mww 0x40022004 0xcdef89ab
    mww 0x40022008 0x45670123
    mww 0x40022008 0xcdef89ab
    mdw 0x40022010
    mdh 0x1ffff800 8
    mww 0x40022010 0x0210
    mwh 0x1ffff800 0x5aa5
    mdw 0x4002200c

I will read how OpenOCD does for unlock.  Probably, it's identification
of the device.

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