[OpenOCD-user] Freescale Kinetis bulk erase / security

[David B. <da...@we...>]

Hi,

I am trying to use OpenOCD (version 0.8.0, currently on Windows but also
testing on Linux) for programming Kinetis K10 devices.  I am using an
Luminary Micros ICDI debugger using interface/ftdi/luminary-icdi.cfg.

I also have access to CodeWarrior and a PE Micro USB device, which I
have used during development - but I want to move to OpenOCD and gdb on
Linux for development, and also use OpenOCD for programming (because we
have several ICDI debugger boards).


With an unsecured Kinetis, I can access it, erase the flash, and program
the device.  But if the Kinetis is secured (as indicated by a particular
value at address 0x40c in flash), then I cannot get any access - most of
the JTAG debugging functionality is disabled.


To be able to re-enable the device, I have to be able to issue a bulk
erase command.  This can be done using the ARM Debug Access Port (DAP)
which is still active.  The MDM-AP is accessible as Debug Access Port 1,
with these registers available:

0x0100_0000 = Status
0x0100_0004 = Control
0x0100_00fc = ID (read only, always reads 0x001c0000)

With the device secured, and most debug features disabled, I can still write

	dap apsel 1

to select access port 1.  The reply I get is:

	ap 1 selected, identification register 0x001c0000

So far, so good.

To issue a "bulk erase" command, all I need to do is set the Control
register to 0x00000001.  (I'd also like to be able to read the Status
register.)


But now I am stuck - I can find no way to access these other DAP
registers.  I am hoping that there is some OpenOCD command that I
haven't noticed, or perhaps some way to use the low-level JTAG commands
for this purpose (I don't know the details of how JTAG works).

I would prefer not to have to change the source code for OpenOCD, though
I suspect that will be necessary at some point to make the process more
user-friendly or even automatic.  The main reason for this is that I
need to be able to run the end result on a Windows machine - and while I
am quite happy editing and rebuilding OpenOCD on Linux, I don't have a
appropriate compiler tools configured for Windows builds.


Any help here would be much appreciated.


David