[U-Boot] More problems booting an i.MX6 from NOR flash

[Carolyn Smith]

Thanks to Dirk for your previous advice. We had a pullup on one of the
reserved BOOT_CFG pins that caused problems accessing NOR flash.

Now I can put code in the NOR flash. If the code is incorrect in some way
(not sure how yet), I end up with a board that I can't get control of with
the BDI. I get

- TARGET: processing reset request
- TARGET: BDI executes scan chain init string
- TARGET: Bypass check 0x00000001 => 0x00000004
- TARGET: JTAG exists check passed
- Core#0: ID code is 0x4BA00477
- Core#0: DP-CSW  is 0xF0000000
- Core#0: DBG-AP  at 0x82150000
- Core#0: DIDR    is 0x3513702A
- TARGET: Reset sequence passed
- TARGET: resetting target passed
- TARGET: processing target startup ....
# TARGET: core #0 startup failed
# TARGET: timeout while waiting for debug mode
# TARGET: processing target startup failed
# TARGET: timeout while waiting for debug mode
I've tried different STARTUP modes, adding WAKEUP delays, different RESET
modes all of which don't help.

Any suggestions?

Thanks,
Carolyn