When you have ever needed to repair a contemporary desktop motherboard, you may need seen that the BIOS (UEFI) SPI flash is 1.8V – which suggests you’ll be able to not use a Raspberry Pi or a CH341 adapter immediately, and also you’d want to make use of a 1.8V stage shifter of some kind. Now, a few of us can await a 1.8V stage shifter adapter from an internet retailer of your selecting, however [treble] acquired a “BIOS flash failed” motherboard from Fb Market, and determined to make it work instantly.
She tells us a narrative about reviving the motherboard, and there’s one factor she exhibits that’s fascinating specifically – a quite simple strategy to stage shift 3.3V indicators from a serprog-flashed Pi Pico all the way down to the 1.8V that the flash chip required, one thing you might be assured to have the ability to construct out of the elements in your elements bin, solely requiring 9 resistors and an NPN transistor. In the event you ever have to reflash BIOS on a contemporary motherboard, take observe. As for 1.8V rail, she ended up tapping the 1.8V energy pin of the SPI chip the motherboard itself to energy the chip whereas programming it.
In the long run, after swapping the 2 BIOS chips locations and fixing a damaged hint mishap, the motherboard booted, and works splendidly to at the present time, a much-needed improve to [treble]’s toolkit that permits her to do RISC-V cross-compiling with ease these days. This isn’t the primary time we see folks reflash fashionable boards with 1.8V chips – if you wish to study extra, try this extremely detailed writeup! Must do some additional debugging? Use your Pico as a POST card!
