DFU (Device Firmware Upgrade) consideration

2012-01-17

There is an opinion that a device like FST-01 should have DFU which allows users (developers) to update its firmware.

Yes, some boards (STBee and STBee Mini, for example) have DfuSe (DFU with STmicroelectronics' extension) installed, which eases developments. Developers are not required to have JTAG/SWD debuggers but can just send firmware with a software tool.

I think that real developer has JTAG/SWD debugger. And I know some bug (or feature) of DfuSe implementation. Thus, I use FST-01 with SWD debugger and don't install any type of DFU.

When you use the device for Gnuk (or similar application), firmware update by DFU might nullify the goodness or the purpose of Gnuk. So, you should be really carefull when you install Gnuk to some board with DFU feature.

The assumption of Gnuk

When user put his keys to Gnuk Token, user expects none is able to read out his keys from the device.

We can lock flash ROM of STM32F103 so that we prohibit access by JTAG/SWD debugger, and Gnuk Token should use this method.

Given the situation that Gnuk doesn't have severe bug to disclose user's key, Gnuk Token could be considered safe with flash ROM lock.

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GnuPG settings for GNOME 3

2011-11-22

In the article GnuPG settings, I wrote how I disable GNOME-keyrings for SSH.

It was for GNOME 2. The old days was good, we just disabled GNOME-keyrings interference to SSH and customizing our desktop was easy for GNU and UNIX users.

GNOME keyrings in GNOME 3

It seems that it is more integrated into the desktop. It is difficult to kill it. It would be possible to kill it simply, but then, I can't use, say, wi-fi access (which needs to access "secrets") any more.

We can't use GNOME configuration tool to disable interference by GNOME keyrings any more. It seems that desktop should not have customization these days.

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Flying Stone Tiny 01 implementation

2011-11-10

Finally, we finished the design of FST-01.

Components of FST-01

  • STM32F103TB
  • SPI Flash memory (32Mbit)
  • USB Terminator
  • LDO Regulator (3.3V)
  • 12MHz XTAL
  • LED
  • SWD Port of GND/SWDIO/SWDCLK
  • Extension port of VDD/GND/Port0/Port1
  • USB plug A
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0.5mm pitch QFN DIY Soldering for FST-01

2011-09-28

For the second experimental version of FST-01, I use STM32F103TB, 36-pin QFN chip.

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0.5mm pitch QFP Hand Soldering for FST-01

2011-09-28

For the first experimental version of FST-01, I use STM32F103CB, 48-pin TQFP chip.

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