hackaday.ioThe Process | Details | Hackaday.io<p>Voltage glitching, also called fault injection, is the process of dumping the energy on a microcontroller's power rail very briefly - Just enough to cause a glitch, where it skips an instruction, rather than causing a brown-out-induced reset.<br></p>
<p>I first learned about the technique in connection with the <a href="https://www.newae.com/chipwhisperer" target="_blank" rel="noopener">Chip Whisperer</a>, which is an FPGA-based board with all the bells and whistles. It's quite expensive, and like any other situation where you add an FPGA, very complicated. Naturally, that has elevated it to a level above what mere mortals can perform in the limited free time we have.</p>
<p>After knowing about this, and having it in the back of my mind for several years, I finally have a good use-case that can justify spending some time on this. I have a pile of generic STM8-based devices, and while I have written some of my own alternative firmware, I'd love to be able to dump the original flash to revert them back to factory code.</p>
<figure><img data-src="https://cdn.hackaday.io/images/4877191641833506552.png" class="lazy"></figure>
<p>The function of the device doesn't matter, that's not the point of this exercise.</p>
<p>Some quick searching for options leads to <a href="https://itooktheredpill.irgendwo.org/2020/stm8-readout-protection/" target="_blank" rel="noopener">this</a> recent write-up, which is sparse on details, but serves as excellent
has somehow slid farther off his cracker. 
