>>>>> "Alberto" == Alberto Bursi <alberto.bu...@outlook.it> writes:
Alberto> On 06/04/2017 02:54 PM, QWeRKUS qwErkus wrote: >> Thank you for your reply. JTAG seems even trickier than serial. So >> far all my attempts to scan for a valid JTAG chain end up with: >> >> Error: JTAG scan chain interrogation failed: all zeroes >> >> There a just too many variables to check for a newbie like myself, so >> I guess I'll go with the spi programmer. Turns out this is another >> thing the pi can do (via flashrom) so no need for new hardware. Are >> you sure you need to desolder the chip though ? Shouldn't this be >> working with a 8 pin SOIC clamp and and external 3.3V power source (I >> have an old ATX PSU doing the job) ? >> >> Alberto> It should, but in some cases it does not (depends from how the Alberto> board was designed) and in those situations you need to Alberto> desolder the chip. I got most of these "cases where it does not Alberto> work" in PC and laptop boards though. If the CPU is trying to access the SPI bus at the same time, it can be problematic. On a TP Link WDR3600 board, I had to figure out how to hold the CPU in reset. You might be able to do that from the JTAG nSRST pin. Make sure it's connected. On the WDR3600 board, there was a shunt resistor missing. http://www.jtagtest.com/pinouts/ejtag Tie nSRST to ground with a jumper wire or similar, attach your SOIC clip, and run flashrom. -- Russell Senior, President russ...@personaltelco.net _______________________________________________ Lede-dev mailing list Lede-dev@lists.infradead.org http://lists.infradead.org/mailman/listinfo/lede-dev