Hi Mathias, > i think it's a initializing problem of the cpu and not a communication > problem. The TAPID is correct received from STLINK but all memory read > fails. > > Is the problem is gone if you press the on-board reset button? > Is your firmware always crash? If so try to hold the reset button and > reconnect.
I think now we are getting somewhere! Thanks a lot for your hint. I did some test and these are the results: - my firmware on stm32f4, openocd, "reset_config srst_only", started with "reset" or "reset halt" -> read errors - my firmware on stm32f4, openocd, "reset_config srst_only srst_nogate", started with "reset" or "reset halt" -> read errors - my firmware on stm32f4, openocd, "reset_config srst_only", started with "reset" or "reset halt", hardware reset button helt down during start of openocd, then released after openocd is initialized -> working - my firmware on stm32f4, stlink utility on windows -> working - default demo firmware on stm32f4, openocd, "reset_config srst_only", started with "reset" or "reset halt" -> working So I conclude there are two problems at play: - the firmware on the stm32f4 has to "play well" with swd. Maybe some kind of initialisation is needed that I'm missing. - there is some special initialisation procedure to make it work even with "non-behaving" firmware on the mcu. The utility from stm does it correctly, but current openocd (=git head + patches from gerrit) not. "reset_config srst_only srst_nogate" is not enough. Maybe there are timing restrictions in the initialisation or reset procedure we have to adhere? When I speak of "my firmware" this is not written by me, but the NuttX RTOS (http://nuttx.sourceforge.net/) with it's nsh example compiled for the f4 discovery. The firmware does not crash but work as expected. It is offering a small shell on USART2. Kind regards, Gerd ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ OpenOCD-devel mailing list OpenOCD-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openocd-devel
