From fdac725d8c0393f04731b8fa50089733627da2fa Mon Sep 17 00:00:00 2001
From: Marian Buschsieweke <marian.buschsieweke@ml-pa.com>
Date: Tue, 5 Nov 2024 13:21:16 +0100
Subject: [PATCH] makefiles/serial: better MOST_RECENT_PORT=1 for CDC ACM

- Allow specifying an alternative board filter for the bootloader TTY,
  as this will present different vendor, model, and serial than RIOT's
  USB implementation.
- Allow specifying the serial. This is useful when multiple CDC ACM
  devices are present.
---
 boards/wemos-zero/Makefile.include | 10 +--------
 makefiles/tools/serial.inc.mk      | 34 +++++++++++++++++++++---------
 2 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/boards/wemos-zero/Makefile.include b/boards/wemos-zero/Makefile.include
index 5e5b9a8673..a28a208e1e 100644
--- a/boards/wemos-zero/Makefile.include
+++ b/boards/wemos-zero/Makefile.include
@@ -5,12 +5,4 @@ include $(RIOTBOARD)/common/arduino-zero/Makefile.include
 # Depending on whether the board is running RIOT or the bootloader, it has
 # registers using a different vendor and model. We try to detect either.
 TTY_BOARD_FILTER := --model $(BOARD) --vendor 'RIOT-os\.org'
-PROG_TTY_BOARD_FILTER := --vendor 'Arduino LLC' --model 'Arduino Zero'
-TTY_SELECT_CMD := $(RIOTTOOLS)/usb-serial/ttys.py \
-                  --most-recent \
-                  --format path serial \
-                  $(TTY_BOARD_FILTER) || \
-                  $(RIOTTOOLS)/usb-serial/ttys.py \
-                  --most-recent \
-                  --format path serial \
-                  $(PROG_TTY_BOARD_FILTER_CLONE)
+PROG_TTY_BOARD_FILTER := --vendor 'Arduino LLC' --model '(Arduino|Genuino) Zero'
diff --git a/makefiles/tools/serial.inc.mk b/makefiles/tools/serial.inc.mk
index 93a135429d..1332bd5f17 100644
--- a/makefiles/tools/serial.inc.mk
+++ b/makefiles/tools/serial.inc.mk
@@ -1,15 +1,29 @@
 # Select the most recently attached tty interface
 ifeq (1,$(MOST_RECENT_PORT))
-  ifneq (,$(filter stdio_cdc_acm,$(USEMODULE)))
-    TTY_SELECT_CMD ?= $(RIOTTOOLS)/usb-serial/ttys.py \
-                      --most-recent \
-                      --format path serial \
-                      --model '$(BOARD)' --vendor 'RIOT-os\.org'
-  else
-    TTY_SELECT_CMD ?= $(RIOTTOOLS)/usb-serial/ttys.py \
-                      --most-recent \
-                      --format path serial \
-                      $(TTY_BOARD_FILTER)
+  ifeq (,$(TTY_SELECT_CMD))
+    ifneq (,$(filter stdio_cdc_acm,$(USEMODULE)))
+      TTY_SELECT_CMD := $(RIOTTOOLS)/usb-serial/ttys.py \
+                        --most-recent \
+                        --format path serial \
+                        --model '$(BOARD)' --vendor 'RIOT-os\.org'
+      # Allow matching board by RIOT serial
+      ifneq (,$(SERIAL))
+        TTY_SELECT_CMD += --serial "$(SERIAL)"
+      endif
+      # Allow matching the bootloader TTY as well, if not running RIOT but
+      # but the bootloader
+      ifneq (,$(PROG_TTY_BOARD_FILTER))
+        TTY_SELECT_CMD += || $(RIOTTOOLS)/usb-serial/ttys.py \
+                             --most-recent \
+                             --format path serial \
+                             $(PROG_TTY_BOARD_FILTER)
+      endif
+    else
+      TTY_SELECT_CMD := $(RIOTTOOLS)/usb-serial/ttys.py \
+                        --most-recent \
+                        --format path serial \
+                        $(TTY_BOARD_FILTER)
+    endif
   endif
   TTY_DETECTED := $(shell $(TTY_SELECT_CMD) || echo 'no-tty-detected no-serial-detected')
   PORT_DETECTED := $(firstword $(TTY_DETECTED))