sw_openocd/src/target/startup.tcl

#########

# This reset logic may be overridden by board/target/... scripts as needed
# to provide a reset that, if possible, is close to a power-up reset.
#
# Exit requirements include:  (a) JTAG must be working, (b) the scan
# chain was validated with "jtag arp_init" (or equivalent), (c) nothing
# stays in reset.  No TAP-specific scans were performed.  It's OK if
# some targets haven't been reset yet; they may need TAP-specific scans.
#
# The "mode" values include:  halt, init, run (from "reset" command);
# startup (at OpenOCD server startup, when JTAG may not yet work); and
# potentially more (for reset types like cold, warm, etc)
proc init_reset { mode } {
	jtag arp_init-reset
}


global in_process_reset
set in_process_reset 0

# Catch reset recursion
proc ocd_process_reset { MODE } {
	global in_process_reset
	if {$in_process_reset} {
		set in_process_reset 0
		return -code error "'reset' can not be invoked recursively"
	}

	set in_process_reset 1
	set success [expr [catch {ocd_process_reset_inner $MODE} result]==0]
	set in_process_reset 0

	if {$success} {
		return $result
	} else {
		return -code error $result
	}
}

proc ocd_process_reset_inner { MODE } {
	set targets [target names]

	# If this target must be halted...
	set halt -1
	if { 0 == [string compare $MODE halt] } {
		set halt 1
	}
	if { 0 == [string compare $MODE init] } {
		set halt 1;
	}
	if { 0 == [string compare $MODE run ] } {
		set halt 0;
	}
	if { $halt < 0 } {
		return -error "Invalid mode: $MODE, must be one of: halt, init, or run";
	}

	# Target event handlers *might* change which TAPs are enabled
	# or disabled, so we fire all of them.  But don't issue any
	# target "arp_*" commands, which may issue JTAG transactions,
	# unless we know the underlying TAP is active.
	#
	# NOTE:  ARP == "Advanced Reset Process" ... "advanced" is
	# relative to a previous restrictive scheme

	foreach t $targets {
		# New event script.
		$t invoke-event reset-start
	}

	# Use TRST or TMS/TCK operations to reset all the tap controllers.
	# TAP reset events get reported; they might enable some taps.
	init_reset $MODE

	# Examine all targets on enabled taps.
	foreach t $targets {
		if {[jtag tapisenabled [$t cget -chain-position]]} {
			$t arp_examine
		}
	}

	# Assert SRST, and report the pre/post events.
	# Note:  no target sees SRST before "pre" or after "post".
	foreach t $targets {
		$t invoke-event reset-assert-pre
	}
	foreach t $targets {
		# C code needs to know if we expect to 'halt'
		if {[jtag tapisenabled [$t cget -chain-position]]} {
			$t arp_reset assert $halt
		}
	}
	foreach t $targets {
		$t invoke-event reset-assert-post
	}

	# Now de-assert SRST, and report the pre/post events.
	# Note:  no target sees !SRST before "pre" or after "post".
	foreach t $targets {
		$t invoke-event reset-deassert-pre
	}
	foreach t $targets {
		# Again, de-assert code needs to know if we 'halt'
		if {[jtag tapisenabled [$t cget -chain-position]]} {
			$t arp_reset deassert $halt
		}
	}
	foreach t $targets {
		$t invoke-event reset-deassert-post
	}

	# Pass 1 - Now wait for any halt (requested as part of reset
	# assert/deassert) to happen.  Ideally it takes effect without
	# first executing any instructions.
	if { $halt } {
		foreach t $targets {
			if {[jtag tapisenabled [$t cget -chain-position]] == 0} {
				continue
			}

			# Wait upto 1 second for target to halt.  Why 1sec? Cause
			# the JTAG tap reset signal might be hooked to a slow
			# resistor/capacitor circuit - and it might take a while
			# to charge

			# Catch, but ignore any errors.
			catch { $t arp_waitstate halted 1000 }

			# Did we succeed?
			set s [$t curstate]

			if { 0 != [string compare $s "halted" ] } {
				return -error [format "TARGET: %s - Not halted" $t]
			}
		}
	}

	#Pass 2 - if needed "init"
	if { 0 == [string compare init $MODE] } {
		foreach t $targets {
			if {[jtag tapisenabled [$t cget -chain-position]] == 0} {
				continue
			}

			set err [catch "$t arp_waitstate halted 5000"]
			# Did it halt?
			if { $err == 0 } {
				$t invoke-event reset-init
			}
		}
	}

	foreach t $targets {
		$t invoke-event reset-end
	}
}

#########

# Temporary migration aid.  May be removed starting in January 2011.
proc armv4_5 params {
	echo "DEPRECATED! use 'arm $params' not 'armv4_5 $params'"
	arm $params
}