Stefan Tauner wrote: > i am currently designing a small and cheap platform to recover from > coreboot and other failures easily.
Yay more flashers. > right now my plan is the following: > an avr atmegaXXu2 is connected via usb and implements the serprog > protocol Please do not! Make good use of USB and design a protocol that actually takes advantage of relevant USB features, instead of pretending that USB is a serial port, which is really lame. At a very minimum translate the serprog protocol to native USB. USB is a packet bus. Making it behave like a dumb stream of bytes is almost never a good idea. Also, make a simple HAL for the AVR, so that your C firmware can be re-used with other processors. I'll make it run on LPC1342/43. > easy interfacing with today's spi flashes SPI access should also be part of the HAL of course. > without any level shifting. Yes, is a good feature. > fixed 3.3V ldo voltage regulator (ld1117). LD? LM? Anyway, that's an 800mA regulator, quite overkill for this application where not even 100mA is required. A smaller one should be cheaper. > - vias for a single row 8pin header to allow attaching probes/test clips > (e.g. http://www.pomonaelectronics.com/images/large/6109.jpg) to hook > up in-situ flashes. May want to consider how the test clip is connected to board. The cables on my clips go to a DIP-style connector that plugs into an 8-pin socket. > parts for this excluding the pcb would be in the 10-25$ range. > depending on how many pcbs i/we would produce the whole thing would > cost probably about 40$. not THAT cheap, but quite better than > the dediprog stuff :) That LPC1343 I mentioned is available on a board from Olimex which is ready made, easy to order at least in Europe, has SPI and power supply on a convenient box header (UEXT) and a small experiment area. http://olimex.com/dev/lpc-p1343.html It's 13 EUR + shipping and VAT. > it would also be more convenient and open than the FT2232SPI Did I mention how I really think USB serial chips are stupid, and FTDI in particular because they have ridiculous prices. > i am not sure about what to do with soic16 chips. I also don't think they are very common. > drop support for them altogether and let the user hook them up with clips? Certainly an option. > i was also thinking about an offline mode which uses an SD-card or > another flash to store/load an image for the target flash. SD is not worth the effort. SD cards are very incompatible and it takes a lot of work to implement a well-functioning card reader. And the filesystems are buggy as well. A second flash chip could be handy for offline mode - but what is supplying the power? //Peter -- coreboot mailing list: coreboot@coreboot.org http://www.coreboot.org/mailman/listinfo/coreboot