Re: [OpenOCD-user] KL26 flash erase

[Patrick S. <pat...@ne...>]

> Hi,
> 
> Please avoid top-posting.
> 
> On Thu, Aug 28, 2014 at 04:06:39PM +0000, Patrick Stewart wrote:
> > After this has happened the chip flash becomes protected, and get
> > stuck in a fast reset loop that prevents openocd from talking to it.
> 
> Hm, with KL25 mdm command to unlock a protected part works 100%
> reliably, I know this firsthand. It would be rather cool to get it working for the
> other kinetis parts as well.
> 
> > I've been using a j-link debugger (not with openocd) to get it out of
> > that state. I've been trying it with lots of minor variations in
> > settings, and it actually worked once and I got a fully working debug
> > session. However it wouldn't work again with the same settings, so I
> > think there might be some kind of race/timing issue.
> 
> So what about my suggestion to nullify the default gdb-flash-erase-start
> event?
> 
> --
> Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
> mailto:fer...@gm...

I got this working in the end with your suggestion to override gdb-flash-erase-start, and fixed the mass_erase by adding in a 'reset halt' which prevents the watchdog reset loop. ApoIogies for not replying earlier, and thanks for your help.
For anyone who's having similar problems, here's my configs:
kinetis-unsecure.cfg:
    interface ftdi
    ftdi_device_desc "SWD SPI Debug Interface"
    ftdi_vid_pid 0x0403 0x7988
    ftdi_channel 1
    ftdi_layout_init 0x0000 0x000b
    ftdi_layout_signal nSRST -data 0x0010 -oe 0x0010
    ftdi_layout_signal SWD_EN -data 0
    ftdi_layout_signal SWDIO_OE -data 0

    transport select swd
    set CHIPNAME MKL26Z256VMP4
    set _CHIPNAME $CHIPNAME
    set _ENDIAN little
    set _WORKAREASIZE 0x1000
    set _CPUTAPID 0x0bc11477
    swd newdap $_CHIPNAME cpu -irlen 4 -expected-id $_CPUTAPID
    set _TARGETNAME $_CHIPNAME.cpu
    target create $_TARGETNAME cortex_m -endian $_ENDIAN -chain-position $_CHIPNAME.cpu

    $_TARGETNAME configure -event examine-end {
        kinetis mdm mass_erase
    }

    $_TARGETNAME configure -work-area-phys 0x20000000 -work-area-size $_WORKAREASIZE -work-area-backup 0
    set _FLASHNAME $_CHIPNAME.flash
    flash bank $_FLASHNAME kinetis 0x00000000 0x40000 0 4 $_TARGETNAME
    adapter_khz 1000
    reset_config srst_only srst_open_drain srst_nogate connect_assert_srst
    cortex_m reset_config sysresetreq

    init
    reset halt
    shutdown

devboard.cfg:
    interface ftdi
    ftdi_device_desc "SWD SPI Debug Interface"
    ftdi_vid_pid 0x0403 0x7988
    ftdi_channel 1
    ftdi_layout_init 0x0000 0x000b
    ftdi_layout_signal nSRST -data 0x0010 -oe 0x0010
    ftdi_layout_signal SWD_EN -data 0
    ftdi_layout_signal SWDIO_OE -data 0

    transport select swd
    set CHIPNAME MKL26Z256VMP4
    set _CHIPNAME $CHIPNAME
    set _ENDIAN little
    set _WORKAREASIZE 0x1000
    set _CPUTAPID 0x0bc11477
    swd newdap $_CHIPNAME cpu -irlen 4 -expected-id $_CPUTAPID
    set _TARGETNAME $_CHIPNAME.cpu
    target create $_TARGETNAME cortex_m -endian $_ENDIAN -chain-position $_CHIPNAME.cpu

    $_TARGETNAME configure -event examine-end {
        kinetis mdm check_security
    }
    $_TARGETNAME configure -event gdb-attach {
       echo "Halting target"
       reset halt
    }
    $_TARGETNAME configure -event gdb-flash-erase-start {
       halt
    }

    $_TARGETNAME configure -work-area-phys 0x20000000 -work-area-size $_WORKAREASIZE -work-area-backup 0
    set _FLASHNAME $_CHIPNAME.flash
    flash bank $_FLASHNAME kinetis 0x00000000 0x40000 0 4 $_TARGETNAME
    adapter_khz 1000
    reset_config srst_only srst_open_drain srst_nogate connect_assert_srst
    cortex_m reset_config sysresetreq

    init
    reset halt