diff options
Diffstat (limited to 'src/target/startup.tcl')
-rw-r--r-- | src/target/startup.tcl | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/src/target/startup.tcl b/src/target/startup.tcl new file mode 100644 index 00000000..d480f335 --- /dev/null +++ b/src/target/startup.tcl @@ -0,0 +1,165 @@ +######### + +# 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 +} |