Make core 0 the default for TCL commands

Signed-off-by: Luke Wren <[email protected]>

tcl/target/rp2040.cfg

@@ -39,6 +39,12 @@ set _FLASHBASE 0x10000000
 # name driver base, size in bytes, chip_width, bus_width, target used to access
 flash bank $_FLASHNAME rp2040_flash $_FLASHBASE $_FLASHSIZE 1 32 $_TARGETNAME_0
 
+# Openocd associates a flash bank with a target (in our case a core) and
+# running `openocd -c "program foo.elf"` just grabs the last selected core
+# from the TCL context. Select `core0` by default so that flash probe
+# succeeds. Note gdb understands there are 2 cores -- this is only for TCL.
+targets rp2040.core0
+
 # srst is not fitted so use SYSRESETREQ to perform a soft reset
 reset_config srst_nogate