scripts: runners: nrf: Honor the --erase flag for external memory

Both backends supported as runners for nRF ICs, nrfjprog and nrfutil,
support erasing external memory as part of the programming operation.
Before this patch, and when the firmware was detected to be partially or
fully placed in external flash by inspecting the .hex address range, the
runner would instruct the backend tool to fully erase the external
flash (but the nrfjprog runner would ignore that, always erasing only
the sectors required). Instead, correctly default to erasing only the
sectors that are required to program the new firmware image in both tools,
and erase it completely only when the --erase flag is provided by the user.

Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>

Author: carlescufi

doc/releases/migration-guide-4.1.rst

@@ -54,6 +54,13 @@ Boards
   instead of pin reset when flashing with ``west flash``. If you want to keep
   using pin reset on the nRF52 family of ICs you can use ``west flash --pinreset``.
 
+* Erasing the external memory when programming a new firmware image with ``west
+  flash`` on the nRF52 and nRF53 series now always correctly honors the
+  ``--erase`` flag (and its absence) both when using the ``nrfjprog`` and
+  ``nrfutil`` backends.  Prior to this release, the ``nrjfprog`` backend would
+  always erase only the sectors of the external flash used by the new firmware,
+  and the ``nrfutil`` one would always erase the whole external flash.
+
 Devicetree
 **********
 

scripts/west_commands/runners/nrf_common.py

@@ -411,7 +411,7 @@ def program_hex(self):
         if self.family in xip_ranges:
             xip_start, xip_end = xip_ranges[self.family]
             if self.hex_refers_region(xip_start, xip_end):
-                ext_mem_erase_opt = 'ERASE_ALL'
+                ext_mem_erase_opt = erase_arg
 
         self.op_program(self.hex_, erase_arg, ext_mem_erase_opt, defer=True, core=core)
         self.flush(force=False)

scripts/west_commands/runners/nrfjprog.py

@@ -91,8 +91,11 @@ def do_exec_op(self, op, force=False):
                 raise RuntimeError(f'Invalid erase mode: {erase}')
 
             if opts.get('ext_mem_erase_mode'):
-                # In the future there might be multiple QSPI erase modes
-                cmd.append('--qspisectorerase')
+                if opts['ext_mem_erase_mode'] == 'ERASE_RANGES_TOUCHED_BY_FIRMWARE':
+                    cmd.append('--qspisectorerase')
+                elif opts['ext_mem_erase_mode'] == 'ERASE_ALL':
+                    cmd.append('--qspichiperase')
+
             if opts.get('verify'):
                 # In the future there might be multiple verify modes
                 cmd.append('--verify')