tcl/target: add rescue mode to RP2040 config

[openocd.git] / tcl / target / rp2040.cfg

diff --git a/tcl/target/rp2040.cfg b/tcl/target/rp2040.cfg
index 0593e03bad273a9f1cd6229e855d03c53b5e4ed1..de76b4e29c33a8e8e0a79dd7792f8e1c2e1b8131 100644 (file)
--- a/tcl/target/rp2040.cfg
+++ b/tcl/target/rp2040.cfg
@@ -26,6 +26,13 @@ if { [info exists CPUTAPID] } {
        set _CPUTAPID 0x01002927
 }
 
+# Set to '1' to start rescue mode
+if { [info exists RESCUE] } {
+       set _RESCUE $RESCUE
+} else {
+       set _RESCUE 0
+}
+
 # Set to '0' or '1' for single core configuration, 'SMP' for -rtos hwthread
 # handling of both cores, anything else for isolated debugging of both cores
 if { [info exists USE_CORE] } {
@@ -37,6 +44,29 @@ set _BOTH_CORES [expr { $_USE_CORE != 0 && $_USE_CORE != 1 }]
 
 swj_newdap $_CHIPNAME cpu -expected-id $_CPUTAPID
 
+# The rescue debug port uses the DP CTRL/STAT bit DBGPWRUPREQ to reset the
+# PSM (power on state machine) of the RP2040 with a flag set in the
+# VREG_AND_POR_CHIP_RESET register. Once the reset is released
+# (by clearing the DBGPWRUPREQ flag), the bootrom will run, see this flag,
+# and halt. Allowing the user to load some fresh code, rather than loading
+# the potentially broken code stored in flash
+if { $_RESCUE } {
+       dap create $_CHIPNAME.rescue_dap -chain-position $_CHIPNAME.cpu -dp-id $_CPUTAPID -instance-id 0xf -ignore-syspwrupack
+       init
+
+       # Clear DBGPWRUPREQ
+       $_CHIPNAME.rescue_dap dpreg 0x4 0x00000000
+
+       # Verifying CTRL/STAT is 0
+       set _CTRLSTAT [$_CHIPNAME.rescue_dap dpreg 0x4]
+       if {[expr {$_CTRLSTAT & 0xf0000000}]} {
+               echo "Rescue failed, DP CTRL/STAT readback $_CTRLSTAT"
+       } else {
+               echo "Now restart OpenOCD without RESCUE flag and load code to RP2040"
+       }
+       shutdown
+}
+
 # core 0
 if { $_USE_CORE != 1 } {
        dap create $_CHIPNAME.dap0 -chain-position $_CHIPNAME.cpu -dp-id $_CPUTAPID -instance-id 0