usage:
	openocd -f cmds/from/file.cfg -c "command inline"

default -f path: /usr/share/openocd/scripts/

starts gdb automatically, gdb_port for setting port, default 3333. use gdb for cpu debugging
can interactively enter commands, telnet_port, default 4444

===

select interface (jtag dongle):

	-f interface/ifname.cfg eg. buspirate

select cpu:

	-f target/targetname.cfg eg. zynq_7000

select devboard (jtag+cpu+...):

	-f board/boardname.cfg eg. stm32f0discovery

see /usr/share/openocd/scripts/ for existing ones

===

general commands:

	help <name> : get help for a command

	exit : close telnet session, leave openocd running

	shutdown : stop openocd

adapter config:

	adapter driver <name> : select adapter driver (cf. interfaces/*.cfg)

	transport select <transport> : select phsyical debug itf (jtag, swd, ...)

	adapter speed <khz> : select jtag/swd/.. speed

debugging:

	init : need to run this before running commands that interact with the device, and after setting up all interfaces/targets/...!

	scan_chain : scan which jtag devices are available

	reg [<name>]: get/set registers

	halt : halt target for debugging

	resume [<addr>]: resume cpu, optionally at addr

	step [<addr>]: step 1 insn, opt. at addr

	reset : hard reset

	m[dw][bhwd] : memory Display/Write, byte/halfword/word/doubleword (8..64 bit)

	dump_image <file> <addr> <size> : dump memory to file

	load_image <file> [<addr>] [<size>] : write file to memory

	virt2phys : addr xlat if mmu enabled

flash commands:

	flash banks : list flash existing on platform

	flash info <bankno> : print info (size, prot, sectors, etc) of flash bank

	flash read_bank <bankno> <filename> [<addr> [<len>]] : dump flash to file

	program <filename> [preverify|verify|reset|exit|<addr>] : program flash

	flash erase_sector <bankno> <startsec> <endsec>|last | erase_address <addr> <len>: erases flash (mmapped). see flash banks/info output

	flash erase_check <bankno> : check if flash is erased

	note: flash drivers can have extra options, w/ lock/protect/... stuff
	not covered: erasing flash

nand commands:

	nand list : like flash banks

	nand probe <num> : needs to be done before commands below

	nand info <num> : show info

	nand dump <num> <file> <off> <len> : dump nand to file

	nand write <num> <file> <off> : write image to nand

	nand erase <num> [<off> <len>] : erase nand

	nand check_bad_blocks <num> : check bad blocks on device

putting it together:

	"i want to load my program into ram & debug it with gdb":

	openocd -f board/mydevboard.cfg -c init -c "load_image myfirmware.elf" -c "reset halt"
		# gdbserver now running on port 3333, halted at reset vector
		# or put this in a script file & then do -f ./thescript.cfg

	"but its not a devboard":

	openocd -f interface/probe.cfg -f target/mymcu.cfg -c init \
		-c "load_image myfirmware.elf" -c "reset halt"
		# gdbserver now running on port 3333, halted at reset vector

	"tell me what this device is":

	openocd -f interface/probe.cfg -c "transport select jtag" -c "adapter speed khz" \
		-c init -c scan_chain -c shutdown
	openocd -f interface/probe.cfg -c "transport select jtag" -c "adapter speed khz" \
		-f target/themcu.fg -c init -c "flash banks" -c "flash info 0" -c shutdown

	"i want to dump the flash in this mcu i found":

	openocd -f interface/probe.cfg  -f target/themcu.fg \
		-c init -c "flash read_bank 0 flashdump.bin" -c shutdown