diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 31a94891..7097ef48 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -5,6 +5,11 @@ on:
     branches: ['**']
   pull_request:
 
+permissions:
+  contents: read
+  pull-requests: write
+  issues: write
+
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -13,18 +18,33 @@ jobs:
 
     steps:
       - uses: actions/checkout@v6
+        with:
+          path: branch
+
+      - uses: actions/checkout@v6
+        with:
+          path: main
+          ref: main
 
       - name: Install dependencies
         run: |
           apt update
           apt install make gcc sdcc xxd python-is-python3 libjson-c-dev zlib1g-dev -y
       - name: Run the host-side unit tests
-        run: make -C test
+        run: cd branch && make -C test
       - name: Check that every machine definition can be compiled
-        run: make machine_check
+        run: cd branch && make machine_check
       - name: Make project (4x2/RTL8372)
-        run: make CI=1 MACHINE="KP_9000_6XHML_X2"
+        run: cd branch && make CI=1 MACHINE="KP_9000_6XHML_X2" && cp output/KP_9000_6XHML_X2/rtlplayground.map /tmp/branch.map
       - name: Make project (8x1/RTL8373)
-        run: make CI=1 MACHINE="KP_9000_9XHML_X_V3_1"
+        run: cd branch && make CI=1 MACHINE="KP_9000_9XHML_X_V3_1"
       - name: Make project with the health instrumentation
-        run: make clean && make CI=1 MACHINE="KP_9000_6XHML_X2" HEALTH=1
+        run: cd branch && make clean && make CI=1 MACHINE="KP_9000_6XHML_X2" HEALTH=1
+      - name: Make main
+        run: cd main && make CI=1 MACHINE="KP_9000_6XHML_X2" && cp output/KP_9000_6XHML_X2/rtlplayground.map /tmp/main.map
+      - name: Calculate bank growth
+        run: |
+          sed -rn 's/^([XCD]SEG|(BANK[0-9])).*=\s+([0-9]+)\. bytes.*$/MAIN_\1=\3/p' /tmp/main.map | sort -u >> "$GITHUB_ENV"
+          sed -rn 's/^([XCD]SEG|(BANK[0-9])).*=\s+([0-9]+)\. bytes.*$/BRANCH_\1=\3/p' /tmp/branch.map | sort -u >> "$GITHUB_ENV"
+          du -sb main/output/KP_9000_6XHML_X2/html_min | awk '{print "MAIN_WEB="$1}' >> "$GITHUB_ENV"
+          du -sb branch/output/KP_9000_6XHML_X2/html_min | awk '{print "BRANCH_WEB="$1}' >>"$GITHUB_ENV"
diff --git a/.gitignore b/.gitignore
index 11f5c4ed..9f544835 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,7 @@
 .gitignore
 .idea/
 output/
+output-main/
 html_data.c
 html_data.h
 version.h
@@ -12,3 +13,4 @@ build/
 # host-test stand-ins for the two generated headers
 !test/stub/html_data.h
 !test/stub/version.h
+.vscode
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8f019c10..879a6682 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -29,6 +29,9 @@
   - Accept firmware uploads regardless of the file part's MIME type, including
     `application/macbinary` sent by Chrome on macOS for `.bin` files.
 
+- Health
+  - `HEALTH=1` builds no longer write past the phase timing arrays at the LLDP checkpoint, which
+    corrupted the `link` slow counter and the DHCP client state. #658
 - Config
   - A startup configuration line longer than the command buffer no longer stops the replay:
     the offending line is skipped and the following lines are still applied.
diff --git a/Makefile b/Makefile
index c95f12af..5754ee08 100644
--- a/Makefile
+++ b/Makefile
@@ -15,11 +15,10 @@ SUBDIRS := tools
 SUBDIRSCLEAN=$(addsuffix clean,$(SUBDIRS))
 
 # $MACHINE selects machine/$(MACHINE).c as the board definition and is passed
-# on as -DMACHINE_$(MACHINE), which the rest of the firmware tests with
-# #if defined(MACHINE_...), and as -DMACHINE_NAME, which machine.h uses to
-# include machine/$(MACHINE).h. Both take the same value, so they cannot drift.
+# on as -DMACHINE_NAME, which machine.h uses to include machine/$(MACHINE).h.
+# Board selection itself needs no MACHINE_* symbol for #if chains, so the
+# definition is all the compiler has to know.
 ifneq ($(MACHINE),)
-	CC_FLAGS += -DMACHINE_$(MACHINE)
 	CC_FLAGS += -DMACHINE_NAME=$(MACHINE)
 endif
 # Health instrumentation and the "health" console command: HEALTH=1 gmake ...
@@ -34,7 +33,16 @@ endif
 # The board definition being built: one file per MACHINE_* symbol in machine.h.
 MACHINE_SRC = machine/$(MACHINE).c
 
-BUILDDIR = output/$(MACHINE)
+MACHINE_INIT_DEFAULT := machine/default_machine_init.c
+MACHINE_INIT_SRC := $(wildcard machine/$(MACHINE)_init.c)
+ifeq ($(MACHINE_INIT_SRC),)
+	MACHINE_INIT_SRC := $(MACHINE_INIT_DEFAULT)
+endif
+
+ifndef BUILDDIR
+	BUILDDIR = output/$(MACHINE)
+endif
+
 VERSION_HEADER := version.h
 
 GIT_VERSION := $(shell git rev-parse --short HEAD)
@@ -61,6 +69,9 @@ endif
 # is built, including the tools/ subdirectory.
 all: create_build_dir $(VERSION_HEADER) $(MACHINE_SRC) $(SUBDIRS) $(BUILDDIR)/rtlplayground-$(FILENAME_EXTENSION).bin
 
+bank_size:
+	tools/bank_occupancy.sh "$(MACHINE)"
+
 create_build_dir:
 	mkdir -p "$(BUILDDIR)"
 	mkdir -p "$(BUILDDIR)/uip"
@@ -81,7 +92,7 @@ $(MACHINE_SRC):
 # invalid $MACHINE value
 SRCS = \
 	$(MACHINE_SRC) \
-	machine_init.c \
+	$(MACHINE_INIT_SRC) \
 	cmd_editor.c \
 	cmd_parser.c \
 	dhcp.c \
@@ -133,7 +144,7 @@ HTML := $(shell find html -name '*.js' -or -name '*.html' -or -name '*.svg' -or
 # Minified copy of the web UI sources, used as the fileadder input.
 # The raw html/ sources stay untouched for development; the minified
 # copy is a build artifact under output/.
-HTML_MIN := output/html_min
+HTML_MIN := $(BUILDDIR)/html_min
 .PHONY: html_min
 html_min: $(HTML)
 	rm -rf $(HTML_MIN)
@@ -141,7 +152,7 @@ html_min: $(HTML)
 	@for f in $(HTML); do python3 tools/minify.py $$f $(HTML_MIN)/$$(basename $$f) || exit 1; done
 
 html_data.c html_data.h &: $(HTML) | tools html_min
-	tools/output/fileadder -a $(HTML_LOCATION) -s $(IMAGESIZE) -b BANK1 -z -d $(HTML_MIN) -p html_data
+	tools/$(BUILDDIR)/fileadder -a $(HTML_LOCATION) -s $(IMAGESIZE) -b BANK1 -z -d $(HTML_MIN) -p html_data
 
 $(VERSION_HEADER): FORCE
 	@printf '%s\n' "#ifndef VERSION_H" "#define VERSION_H" \
@@ -155,7 +166,7 @@ $(VERSION_HEADER): FORCE
 httpd: html_data.h
 
 $(SUBDIRS):
-	$(MAKE) -C $@
+	$(MAKE) -C $@ BUILDDIR=$(BUILDDIR)
 
 clean: $(SUBDIRSCLEAN)
 	-rm -f html_data.c html_data.h $(VERSION_HEADER)
@@ -193,31 +204,35 @@ $(BUILDDIR)/rtlplayground.img: $(BUILDDIR)/rtlplayground.ihx
 
 $(BUILDDIR)/rtlplayground-$(FILENAME_EXTENSION).bin: $(BUILDDIR)/rtlplayground.img | tools
 	if [ -e $@ ]; then rm $@; fi
-	tools/output/imagebuilder -i $^ $@
-	tools/output/fileadder -a $(DEFAULT_CONFIG_LOCATION) -s $(IMAGESIZE) -d config.txt $@
-	tools/output/fileadder -a $(CONFIG_LOCATION) -s $(IMAGESIZE) -d config.txt $@
-	tools/output/fileadder -a $(HTML_LOCATION) -s $(IMAGESIZE) -z -d $(HTML_MIN) -b BANK1 $@
-	tools/output/crc_calculator -u $@
-	ln -sf $(MACHINE)/rtlplayground-$(FILENAME_EXTENSION).bin output/rtlplayground.bin
+	tools/$(BUILDDIR)/imagebuilder -i $^ $@
+	tools/$(BUILDDIR)/fileadder -a $(DEFAULT_CONFIG_LOCATION) -s $(IMAGESIZE) -d config.txt $@
+	tools/$(BUILDDIR)/fileadder -a $(CONFIG_LOCATION) -s $(IMAGESIZE) -d config.txt $@
+	tools/$(BUILDDIR)/fileadder -a $(HTML_LOCATION) -s $(IMAGESIZE) -z -d $(HTML_MIN) -b BANK1 $@
+	tools/$(BUILDDIR)/crc_calculator -u $@
+	ln -sf $(MACHINE)/rtlplayground-$(FILENAME_EXTENSION).bin $(BUILDDIR)/../rtlplayground.bin
 
 .PHONY: clean distclean all $(SUBDIRS) $(SUBDIRSCLEAN) create_build_dir
 
 # Every machine/ definition is compiled, so a machine added to machine/ is
-# covered without registering it anywhere. The machine-specific defines are
+# covered without registering it anywhere. The _init.c files are excluded here:
+# they are the boot hooks, compiled separately below (the board's own if it
+# exists, otherwise default_machine_init.c). The machine-specific defines are
 # filtered out of $(CC_FLAGS) and supplied per iteration instead, so this also
 # works as "make machine_check MACHINE=...".
-MACHINE_DEFS := $(sort $(patsubst machine/%.c,%,$(wildcard machine/*.c)))
+MACHINE_DEFS := $(sort $(patsubst machine/%.c,%,$(filter-out machine/%_init.c,$(wildcard machine/*.c))))
 MACHINE_LESS_CC_FLAGS = $(filter-out -DMACHINE_%,$(CC_FLAGS))
 
-.PHONY:
+.PHONY: machine_check
 machine_check:
 	@mkdir -p $(BUILDDIR)/tmp
 	@set -eo pipefail; \
 	for MACHINE in $(MACHINE_DEFS); \
 	do \
 	echo "Checking $${MACHINE}"; \
-	$(CC) $(MACHINE_LESS_CC_FLAGS) -DMACHINE_$${MACHINE} -DMACHINE_NAME=$${MACHINE} -MMD -o $(BUILDDIR)/tmp/machine_check -c machine/$${MACHINE}.c; \
-	$(CC) $(MACHINE_LESS_CC_FLAGS) -DMACHINE_$${MACHINE} -DMACHINE_NAME=$${MACHINE} -MMD -o $(BUILDDIR)/tmp/machine_check -c machine_init.c; \
+	$(CC) $(MACHINE_LESS_CC_FLAGS) -DMACHINE_NAME=$${MACHINE} -MMD -o $(BUILDDIR)/tmp/machine_check -c machine/$${MACHINE}.c; \
+	INIT=machine/$${MACHINE}_init.c; \
+	if [ ! -e $$INIT ] && [ ! -L $$INIT ]; then INIT=$(MACHINE_INIT_DEFAULT); fi; \
+	$(CC) $(MACHINE_LESS_CC_FLAGS) -DMACHINE_NAME=$${MACHINE} -MMD -o $(BUILDDIR)/tmp/machine_check -c $$INIT; \
 	done
 	@rm -rf $(BUILDDIR)/tmp
 
diff --git a/cmd_parser.c b/cmd_parser.c
index afc7831a..f7b1f5cb 100644
--- a/cmd_parser.c
+++ b/cmd_parser.c
@@ -266,7 +266,7 @@ uint8_t cmd_parse_port(uint8_t idx) {
 		return 0;
 
 	port = machine.phys_to_log_port[port];
-	if (port < machine.min_port || port > machine.max_port)
+	if (!MACHINE_PORT_VALID(port))
 		return 0;
 
 	atoi_results_u8 = port;
@@ -743,7 +743,7 @@ void parse_isolate(void)
     }
 
 	if (cmd_compare(2, "off")) {
-		for (uint8_t i = machine.min_port; i <= machine.max_port; i++)
+		for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++)
 			members |= ((uint16_t)1) << i;
 		members |= PMASK_CPU; // CPU-port
 		port_isolate(port_configured, members);
@@ -797,7 +797,7 @@ void parse_ingress(void)
 		if (!cmd_is_space_or_nul(idx))
 			goto err;
 		// Setting mode for all ports at once
-		for (log_port = machine.min_port; log_port <= machine.max_port; log_port++) {
+		for (log_port = MACHINE_MIN_PORT; log_port <= MACHINE_MAX_PORT; log_port++) {
 			if (!port_ingress_filter(log_port, mode)) {
 				cmd_error("cannot set the ingress filter for port "); print_phys_port(log_port); write_char('\n');
 				return;
@@ -1019,7 +1019,7 @@ void parse_mtu(void)
 	uint8_t p;
 
 	if (cmd_compare(1, "show")) {
-		for (p = machine.min_port; p <= machine.max_port; p++) {
+		for (p = MACHINE_MIN_PORT; p <= MACHINE_MAX_PORT; p++) {
 			reg_read_m(RTL8373_REG_MAC_L2_PORT_MAX_LEN + ((uint16_t) p << 8));
 			uint16_t mtu = SFR_DATA_U16 & 0x3fff;
 			print_string("Port "); print_phys_port(p);
@@ -2329,6 +2329,7 @@ void health_show(void) __banked
 	ph_line("tx  ", HEALTH_PH_TX);
 	ph_line("stp ", HEALTH_PH_STP);
 	ph_line("cmd ", HEALTH_PH_CMD);
+	ph_line("lldp", HEALTH_PH_LLDP);
 
 	/* Stack: current depth plus how much of the painted area is untouched */
 	print_string("sp ");
diff --git a/cmd_parser.h b/cmd_parser.h
index 2359eb16..e6a073ab 100644
--- a/cmd_parser.h
+++ b/cmd_parser.h
@@ -19,8 +19,8 @@ extern __xdata uint8_t err_status;
 #define HEALTH_PH_TX	3
 #define HEALTH_PH_STP	4
 #define HEALTH_PH_CMD	5
-#define HEALTH_PHASES	6
-#define HEALTH_LLDP     7
+#define HEALTH_PH_LLDP	6
+#define HEALTH_PHASES	(HEALTH_PH_LLDP + 1)	/* last id + 1: sizes the arrays in cmd_parser.c */
 
 extern __xdata uint16_t health_rx_frames;
 #define health_rx_frame()	health_rx_frames++
diff --git a/doc/adding-a-device.md b/doc/adding-a-device.md
index 312f318f..7e2aa150 100644
--- a/doc/adding-a-device.md
+++ b/doc/adding-a-device.md
@@ -15,6 +15,7 @@ make MACHINE=<NAME>
 |------|---------|
 | `machine/<NAME>.c` | the `struct machine machine` board definition |
 | `machine/<NAME>.h` | `MACHINE_MODEL` (the model string shown in the UI and the CLI) and `MACHINE_CHIPSET` (`RTL8372` or `RTL8373`) |
+| `machine/<NAME>_init.c` | optional `machine_custom_init()` boot hook, for registers the machine definition cannot express |
 | `doc/devices/<name>.md` + `doc/supported_devices.md` | (only if the board is verified and you want to support it publicly) user-facing documentation |
 
 `<NAME>` is the machine symbol without its `MACHINE_` prefix, so `MACHINE` is
@@ -37,8 +38,8 @@ existing files as the template:
 ```
 
 `MACHINE_CHIPSET` is `RTL8373` or `RTL8372`; a build without it will fail. It selects the default
-logical port range: `min_port` is `0` for RTL8373 and `3` for RTL8372, while `max_port` is `8`,
-the highest logical port index. A board with a different range defines
+logical port range: `MACHINE_MIN_PORT` is `0` for RTL8373 and `3` for RTL8372, while
+`MACHINE_MAX_PORT` is `8`, the highest logical port index. A board with a different range defines
 `MACHINE_MIN_PORT` and/or `MACHINE_MAX_PORT` in its header to override the
 defaults.
 
@@ -93,16 +94,16 @@ __code const struct machine machine = {
 };
 ```
 
-`MACHINE_COMMON_SETTING` (from `machine_defs.h`) initializes `machine_name`,
-`isRTL8373`, `min_port` and `max_port` from the header's `MACHINE_MODEL` and
-`MACHINE_CHIPSET`. Keep it as the first initializer and list the
-board-specific fields after it.
+`MACHINE_COMMON_SETTING` (from `machine_defs.h`) initializes `machine_name` and
+`isRTL8373` from the header's `MACHINE_MODEL` and `MACHINE_CHIPSET`. The logical
+port range comes from `MACHINE_MIN_PORT` and `MACHINE_MAX_PORT` in `machine.h`.
+Keep it as the first initializer and list the board-specific fields after it.
 
 ### Fields
 
 | Field | Meaning |
 |-------|---------|
-| `MACHINE_COMMON_SETTING` | expands to `machine_name` (`MACHINE_MODEL`), `isRTL8373` (`1` for `RTL8373`, `0` for `RTL8372`), `min_port` and `max_port`; all are derived from the header's `MACHINE_CHIPSET` (see Step 1) |
+| `MACHINE_COMMON_SETTING` | expands to `machine_name` (`MACHINE_MODEL`) and `isRTL8373` (`1` for `RTL8373`, `0` for `RTL8372`); both are derived from the header's `MACHINE_CHIPSET` (see Step 1) |
 | `n_sfp` | number of SFP+ cages |
 | `n_10g` | SerDes 10G capability used by the RTL837xN init: `0` none, `1` one, `2` two 10G-capable SerDes |
 | `log_to_phys_port[9]` | logical port (0-based index) → physical front-panel port number |
@@ -147,6 +148,20 @@ and the six `KP_9000_*` revision variants.
 Two files that differ only in whitespace or comments are duplicates and should
 be collapsed this way.
 
+### Optional custom init hook
+
+If the board needs custom initialization, add
+`machine/<NAME>_init.c` defining `machine_custom_init()`. The Makefile picks the
+file up by name and compiles it.
+
+Boards that need the same hook share one file: keep the code in a single
+`machine/<NAME>_init.c` whose `machine/<NAME>.c` is a real file (not a symlink),
+and make the other boards' `_init.c` symlinks to it, for example:
+
+```
+ln -s KP_9000_6XH_X2_init.c machine/MY_BOARD_1_0_init.c
+```
+
 ## Step 3: build and verify
 
 ```
@@ -160,7 +175,7 @@ file, before anything is compiled.
 Then run the checks CI runs:
 
 ```
-make machine_check    # compiles machine/<NAME>.c and machine_init.c for every machine
+make machine_check    # compiles machine/<NAME>.c and its optional _init.c for every machine
 make -C test          # host-side unit tests
 ```
 
diff --git a/doc/health.md b/doc/health.md
index 736d52b7..af6b8a28 100644
--- a/doc/health.md
+++ b/doc/health.md
@@ -14,6 +14,7 @@ rx   max 00 slow 0x0000
 tx   max 00 slow 0x0000
 stp  max 04 slow 0x0001
 cmd  max 02 slow 0x0001
+lldp max 00 slow 0x0000
 sp 80 untouched 62
 tcp st 00 tmr 00 rtx 00 rto 00 len 0x0000 mss 0x05b4
   lport 0x0000 rport 0x0000 rip 0x0000 0x0000
@@ -46,7 +47,7 @@ a flooded CPU port from a stalled loop, which look identical from outside.
 ## Phases
 
 Each line is one section of the main loop: the link poll, SFP handling,
-frame reception, TCP transmission, the STP timers and the command dispatch.
+frame reception, TCP transmission, the STP timers, the LLDP timer and the command dispatch.
 `max` is the worst time that section has taken, in ticks of 5 ms; `slow`
 counts the passes that took two ticks or more. A misbehaving subsystem
 names itself here, which is the difference between knowing that the loop is
diff --git a/httpd/page_impl.c b/httpd/page_impl.c
index 006d2dbe..7f107b7d 100644
--- a/httpd/page_impl.c
+++ b/httpd/page_impl.c
@@ -341,7 +341,7 @@ void send_vlan(uint16_t vlan)
 	}
 	slen += strtox(outbuf + slen, "\",\"pvid\":\"0x");
 	uint16_t pvid_mask = 0;
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		if (port_pvid_get(i) == vlan)
 			pvid_mask |= (1 << i);
 }
@@ -357,7 +357,7 @@ void send_vlan(uint16_t vlan)
 bool send_counters(uint8_t phys_port)
 {
 	uint8_t phys_port_idx = phys_port - 1;
-	if (phys_port_idx > (machine.max_port - machine.min_port))
+	if (phys_port_idx > (MACHINE_MAX_PORT - MACHINE_MIN_PORT))
 		goto err;
 	uint8_t log_port = machine.phys_to_log_port[phys_port_idx];
 
@@ -676,7 +676,7 @@ void send_stp(void)
 	slen += strtox(outbuf + slen, "\",\"ports\":[");
 	reg_read_m(RTL837X_MSTP_STATES);
 	for (i = 0; i < STP_ENTITIES; i++) {
-		if (i < STP_LAG_BASE && (i < machine.min_port || i > machine.max_port))
+		if (i < STP_LAG_BASE && !MACHINE_PORT_VALID(i))
 			continue;
 		if (i < STP_LAG_BASE && stp_ent_of[i] != i)
 			continue;
@@ -761,7 +761,7 @@ void send_lacp(void)
 	}
 	slen -= 1; // remove comma
 	slen += strtox(outbuf + slen, "],\"ports\":[");
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		slen += strtox(outbuf + slen, "{\"p\":");
 		itoa_html(machine.log_to_phys_port[i]);
 		slen += strtox(outbuf + slen, ",\"lag\":");
@@ -793,7 +793,7 @@ void send_lldp(void)
 	bool_to_html(lldp_enabled);
 	slen += strtox(outbuf + slen, ",\"portStatus\":[");
 
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		slen += strtox(outbuf + slen, "{\"portNum\":");
 		itoa_html(machine.log_to_phys_port[i]);
 
@@ -808,7 +808,7 @@ void send_lldp(void)
 		bool_to_html(1 & (lldp_logical_port_status >> i));
 		slen += strtox(outbuf + slen, "}");
 
-		if (i < machine.max_port)
+		if (i < MACHINE_MAX_PORT)
 			char_to_html(',');
 		else
 			char_to_html(']');
@@ -825,7 +825,7 @@ void send_eee(void)
 	uint8_t eee_ablty = sfr_data[3];
 
 	char_to_html('[');
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		slen += strtox(outbuf + slen, "{\"portNum\":");
 		itoa_html(machine.log_to_phys_port[i]);
 
@@ -857,7 +857,7 @@ void send_eee(void)
 			bool_to_html(eee_ablty & (1 << i));
 		}
 		char_to_html('}');
-		if (i < machine.max_port)
+		if (i < MACHINE_MAX_PORT)
 			char_to_html(',');
 		else
 			char_to_html(']');
@@ -870,7 +870,7 @@ void send_bandwidth(void)
 	dbg_string("send_bandwidth called\n");
 	slen = strtox(outbuf, HTTP_RESPONCE_JSON);
 	char_to_html('[');
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		slen += strtox(outbuf + slen, "{\"portNum\":");
 		itoa_html(machine.log_to_phys_port[i]);
 		slen += strtox(outbuf + slen, ",\"iLimited\":");
@@ -900,7 +900,7 @@ void send_bandwidth(void)
 		byte_to_html(sfr_data[3]);
 		char_to_html('"');
 		char_to_html('}');
-		if (i < machine.max_port)
+		if (i < MACHINE_MAX_PORT)
 			char_to_html(',');
 		else
 			char_to_html(']');
@@ -914,7 +914,7 @@ void send_storm(void)
 
 	slen = strtox(outbuf, HTTP_RESPONCE_JSON);
 	char_to_html('[');
-	for (i = machine.min_port; i <= machine.max_port; i++) {
+	for (i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		slen += strtox(outbuf + slen, "{\"portNum\":");
 		itoa_html(machine.log_to_phys_port[i]);
 		slen += strtox(outbuf + slen, ",\"en\":\"");
@@ -934,7 +934,7 @@ void send_storm(void)
 		}
 		char_to_html('"');
 		char_to_html('}');
-		if (i < machine.max_port)
+		if (i < MACHINE_MAX_PORT)
 			char_to_html(',');
 		else
 			char_to_html(']');
@@ -949,7 +949,7 @@ void send_isolation(void)
 	dbg_string("send_isolation called\n");
 	slen = strtox(outbuf, HTTP_RESPONCE_JSON);
 	char_to_html('[');
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		slen += strtox(outbuf + slen, "{\"portNum\":");
 		itoa_html(machine.log_to_phys_port[i]);
 		slen += strtox(outbuf + slen, ",\"allow\":\"");
@@ -958,7 +958,7 @@ void send_isolation(void)
 		byte_to_html(allow & 0xff);
 		char_to_html('"');
 		char_to_html('}');
-		if (i < machine.max_port)
+		if (i < MACHINE_MAX_PORT)
 			char_to_html(',');
 	}
 	char_to_html(']');
@@ -970,7 +970,7 @@ void send_mtu(void)
 	dbg_string("send_mtu called\n");
 	slen = strtox(outbuf, HTTP_RESPONCE_JSON);
 	char_to_html('[');
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		slen += strtox(outbuf + slen, "{\"portNum\":");
 		itoa_html(machine.log_to_phys_port[i]);
 		slen += strtox(outbuf + slen, ",\"mtu\":\"0x");
@@ -980,7 +980,7 @@ void send_mtu(void)
 		byte_to_html(mtu & 0xff);
 		char_to_html('"');
 		char_to_html('}');
-		if (i < machine.max_port)
+		if (i < MACHINE_MAX_PORT)
 			char_to_html(',');
 		else
 			char_to_html(']');
@@ -994,7 +994,7 @@ void send_status(void)
 	dbg_string("sending status\n");
 	char_to_html('[');
 
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		slen += strtox(outbuf + slen, "{\"portNum\":");
 		itoa_html(machine.log_to_phys_port[i]);
 		slen += strtox(outbuf + slen, ",\"logPort\":");
@@ -1115,7 +1115,7 @@ void send_status(void)
 		slen += strtox(outbuf + slen, "\",\"macs\":\"0x");
 		reg_to_html(RTL837X_L2_LRN_PORT_CONSTRT_CNT + (i << 2));
 		slen += strtox(outbuf + slen, "\"}");
-		if (i < machine.max_port)
+		if (i < MACHINE_MAX_PORT)
 			char_to_html(',');
 		else
 			char_to_html(']');
diff --git a/machine.h b/machine.h
index 70d75e8b..78dfd77a 100644
--- a/machine.h
+++ b/machine.h
@@ -42,6 +42,9 @@
 #endif
 #endif
 
+#define MACHINE_PORT_VALID(p) \
+	((uint8_t)((p) - MACHINE_MIN_PORT) <= (MACHINE_MAX_PORT - MACHINE_MIN_PORT))
+
 // auto derive SOC_FAMILY
 #define RTL836X 6
 #define RTL837X 7
@@ -81,10 +84,6 @@ struct sfp_port
 struct machine {
 	char machine_name[30];
 	uint8_t isRTL8373;
-	// Lowest logical port number
-	uint8_t min_port;
-	// Highest logical port number
-	uint8_t max_port;
 	uint8_t n_sfp;
 	uint8_t n_10g;
 	uint8_t log_to_phys_port[9];
diff --git a/machine/2G5F4_10G2_V1_01.c b/machine/2G5F4_10G2_V1_01.c
index e4a78ad1..caca361d 100644
--- a/machine/2G5F4_10G2_V1_01.c
+++ b/machine/2G5F4_10G2_V1_01.c
@@ -41,8 +41,8 @@ __code const struct machine machine = {
 	 * at 2.5G only) and LED-ID2 carries the SFP single LED. The "solid"
 	 * conditions (LINK/speed) barely drive the LEDs here and ACT is what
 	 * actually lights them, which is why the white LED used to glow faintly at
-	 * non-2.5G speeds; the fix for that is LED_GLB_IO_EN bit 6, set in
-	 * machine_init.c. */
+	 * non-2.5G speeds; the fix for that is LED_GLB_IO_EN bit 6, set in the
+	 * shared machine_custom_init() hook (machine/2G5F4_10G2_V1_01_init.c). */
 	.led_sets = { { LEDS_2G5 | LEDS_1G | LEDS_100M | LEDS_10M | LEDS_LINK | LEDS_ACT | LEDS_10G,
 			LEDS_2G5 | LEDS_LINK | LEDS_10G,
 			LEDS_1G | LEDS_LINK,
diff --git a/machine/2G5F4_10G2_V1_01_init.c b/machine/2G5F4_10G2_V1_01_init.c
new file mode 120000
index 00000000..37370e2a
--- /dev/null
+++ b/machine/2G5F4_10G2_V1_01_init.c
@@ -0,0 +1 @@
+KP_9000_6XH_X2_init.c
\ No newline at end of file
diff --git a/machine/FG_4GT_2SX_V2_0_init.c b/machine/FG_4GT_2SX_V2_0_init.c
new file mode 100644
index 00000000..c9b9ddab
--- /dev/null
+++ b/machine/FG_4GT_2SX_V2_0_init.c
@@ -0,0 +1,6 @@
+#include "machine_init_defs.h"
+
+void machine_custom_init(void) __banked
+{
+	REG_SET(RTL837X_REG_LED_GLB_IO_EN, 0x7624155b);
+}
diff --git a/machine/FNS1200P_init.c b/machine/FNS1200P_init.c
new file mode 120000
index 00000000..37370e2a
--- /dev/null
+++ b/machine/FNS1200P_init.c
@@ -0,0 +1 @@
+KP_9000_6XH_X2_init.c
\ No newline at end of file
diff --git a/machine/HI_K0402WS_init.c b/machine/HI_K0402WS_init.c
new file mode 120000
index 00000000..37370e2a
--- /dev/null
+++ b/machine/HI_K0402WS_init.c
@@ -0,0 +1 @@
+KP_9000_6XH_X2_init.c
\ No newline at end of file
diff --git a/machine/KP_9000_6XHML_X2_V2_1_init.c b/machine/KP_9000_6XHML_X2_V2_1_init.c
new file mode 120000
index 00000000..37370e2a
--- /dev/null
+++ b/machine/KP_9000_6XHML_X2_V2_1_init.c
@@ -0,0 +1 @@
+KP_9000_6XH_X2_init.c
\ No newline at end of file
diff --git a/machine/KP_9000_6XH_X2_V2_1_init.c b/machine/KP_9000_6XH_X2_V2_1_init.c
new file mode 120000
index 00000000..37370e2a
--- /dev/null
+++ b/machine/KP_9000_6XH_X2_V2_1_init.c
@@ -0,0 +1 @@
+KP_9000_6XH_X2_init.c
\ No newline at end of file
diff --git a/machine/KP_9000_6XH_X2_init.c b/machine/KP_9000_6XH_X2_init.c
new file mode 100644
index 00000000..394f71ef
--- /dev/null
+++ b/machine/KP_9000_6XH_X2_init.c
@@ -0,0 +1,6 @@
+#include "machine_init_defs.h"
+
+void machine_custom_init(void) __banked
+{
+	reg_bit_set(RTL837X_REG_LED_GLB_IO_EN, 6);
+}
diff --git a/machine/PCB_K0402WS_V2_init.c b/machine/PCB_K0402WS_V2_init.c
new file mode 120000
index 00000000..37370e2a
--- /dev/null
+++ b/machine/PCB_K0402WS_V2_init.c
@@ -0,0 +1 @@
+KP_9000_6XH_X2_init.c
\ No newline at end of file
diff --git a/machine/PCB_K0402WS_V3_init.c b/machine/PCB_K0402WS_V3_init.c
new file mode 120000
index 00000000..37370e2a
--- /dev/null
+++ b/machine/PCB_K0402WS_V3_init.c
@@ -0,0 +1 @@
+KP_9000_6XH_X2_init.c
\ No newline at end of file
diff --git a/machine/PCB_SWTG018AS_V2_1_0_init.c b/machine/PCB_SWTG018AS_V2_1_0_init.c
new file mode 100644
index 00000000..bce0b814
--- /dev/null
+++ b/machine/PCB_SWTG018AS_V2_1_0_init.c
@@ -0,0 +1,18 @@
+#include "machine_init_defs.h"
+
+static __code const struct { uint16_t reg; uint32_t val; } custom_init_regs[] = {
+	{ RTL837X_REG_LED3_0_SET1,   0x00100000UL },
+	{ RTL837X_REG_LED1_0_SET1,   0x01400155UL },
+	{ RTL837X_REG_LED1_0_SET0,   0x01740141UL },
+	{ RTL837X_REG_LED_GLB_IO_EN, 0x7f24977fUL },
+	{ RTL837X_PIN_MUX_0,         0x20db6880UL },
+};
+
+void machine_custom_init(void) __banked
+{
+	uint8_t i;
+	// REG_SET is a multi-statement macro without a do-while wrapper: braces required
+	for (i = 0; i < sizeof(custom_init_regs) / sizeof(custom_init_regs[0]); i++) {
+		REG_SET(custom_init_regs[i].reg, custom_init_regs[i].val);
+	}
+}
diff --git a/machine/PCB_SWTG024AS_A_2_0_1_init.c b/machine/PCB_SWTG024AS_A_2_0_1_init.c
new file mode 100644
index 00000000..311bda3e
--- /dev/null
+++ b/machine/PCB_SWTG024AS_A_2_0_1_init.c
@@ -0,0 +1,9 @@
+#include "machine_init_defs.h"
+
+void machine_custom_init(void) __banked
+{
+	reg_bit_set(RTL837X_REG_LED_GLB_IO_EN, 6);
+	reg_bit_set(RTL837X_REG_LED_MODE, 17);
+	reg_bit_clear(RTL837X_REG_LED_MODE, 9);
+	reg_bit_clear(RTL837X_REG_LED_MODE, 7);
+}
diff --git a/machine/SWTG024AS_A_2_0_1_5C_1SFP_init.c b/machine/SWTG024AS_A_2_0_1_5C_1SFP_init.c
new file mode 120000
index 00000000..6297e789
--- /dev/null
+++ b/machine/SWTG024AS_A_2_0_1_5C_1SFP_init.c
@@ -0,0 +1 @@
+SWTG024AS_V2_0_init.c
\ No newline at end of file
diff --git a/machine/SWTG024AS_V2_0_init.c b/machine/SWTG024AS_V2_0_init.c
new file mode 100644
index 00000000..98d2f0c6
--- /dev/null
+++ b/machine/SWTG024AS_V2_0_init.c
@@ -0,0 +1,20 @@
+#include "machine_init_defs.h"
+
+void machine_custom_init(void) __banked
+{
+	uint16_t pval;
+
+	reg_bit_set(RTL837X_REG_LED_GLB_IO_EN, 6);
+	reg_bit_set(RTL837X_REG_LED_MODE, 17);
+	reg_bit_clear(RTL837X_REG_LED_MODE, 9);
+	reg_bit_clear(RTL837X_REG_LED_MODE, 7);
+
+	// OEM firmware sets these companion SDS0 polarity bits for the RTL8221B.
+	sds_read(0, 0, 0);
+	pval = SFR_DATA_U16;
+	sds_write_v(0, 0, 0, pval | 0x100);
+
+	sds_read(0, 6, 2);
+	pval = SFR_DATA_U16;
+	sds_write_v(0, 6, 2, pval | 0x4000);
+}
diff --git a/machine/ZX310S_4T2XT_init.c b/machine/ZX310S_4T2XT_init.c
new file mode 100644
index 00000000..38a96e25
--- /dev/null
+++ b/machine/ZX310S_4T2XT_init.c
@@ -0,0 +1,8 @@
+#include "machine_init_defs.h"
+
+void machine_custom_init(void) __banked
+{
+	// For this device, the reset value of RTL837X_PIN_MUX_0 is 0x30000000,
+	// which would disables all LEDS, enable them manually:
+	REG_SET(RTL837X_PIN_MUX_0, 0x30db68bf);
+}
diff --git a/machine/default_machine_init.c b/machine/default_machine_init.c
new file mode 100644
index 00000000..1ee200f5
--- /dev/null
+++ b/machine/default_machine_init.c
@@ -0,0 +1,6 @@
+/*
+ * Fallback boot hook for boards without a machine/<MACHINE>_init.c.
+ */
+#include "machine_init_defs.h"
+
+void machine_custom_init(void) __banked { }
diff --git a/machine/machine_defs.h b/machine/machine_defs.h
index 4775a58f..be77636d 100644
--- a/machine/machine_defs.h
+++ b/machine/machine_defs.h
@@ -43,8 +43,6 @@
 
 #define MACHINE_COMMON_SETTING \
 	.machine_name = MACHINE_MODEL, \
-	.isRTL8373 = MACHINE_CHIPSET == RTL8373, \
-	.min_port = MACHINE_MIN_PORT, \
-	.max_port = MACHINE_MAX_PORT
+	.isRTL8373 = MACHINE_CHIPSET == RTL8373
 
 #endif
diff --git a/machine/machine_init_defs.h b/machine/machine_init_defs.h
new file mode 100644
index 00000000..b3507d25
--- /dev/null
+++ b/machine/machine_init_defs.h
@@ -0,0 +1,10 @@
+#ifndef _MACHINE_INIT_DEFS_H_
+#define _MACHINE_INIT_DEFS_H_
+
+
+#include "machine_defs.h"
+
+#pragma codeseg BANK2
+#pragma constseg BANK2
+
+#endif
diff --git a/machine_init.c b/machine_init.c
deleted file mode 100644
index efb16e61..00000000
--- a/machine_init.c
+++ /dev/null
@@ -1,96 +0,0 @@
-/*
- * Per-machine one-shot boot hooks, hosted in BANK2 so board-specific
- * tables and code do not consume the common bank.
- */
-#include <stdint.h>
-#include "machine.h"
-#include "rtl837x_pins.h"
-#include "rtl837x_leds.h"
-#include "rtl837x_sfr.h"
-#include "rtl837x_regs.h"
-#include "rtl837x_common.h"
-
-#pragma codeseg BANK2
-#pragma constseg BANK2
-
-#if defined(MACHINE_KP_9000_6XH_X2) || \
-	defined(MACHINE_KP_9000_6XH_X2_V2_1) || \
-	defined(MACHINE_KP_9000_6XHML_X2_V2_1) || \
-	defined(MACHINE_HI_K0402WS) || \
-	defined(MACHINE_PCB_K0402WS_V2) || \
-	defined(MACHINE_PCB_K0402WS_V3) || \
-	defined(MACHINE_2G5F4_10G2_V1_01) || \
-	defined(MACHINE_FNS1200P)
-void machine_custom_init(void) __banked
-{
-	reg_bit_set(RTL837X_REG_LED_GLB_IO_EN, 6);
-}
-
-#elif defined MACHINE_PCB_SWTG018AS_V2_1_0
-// Stock-firmware values for what the LED-set encoding cannot express: the
-// bi-color SFP LED (blue pin at 10G) and the PIN_MUX_0 routing of that pin
-// to the LED controller. Runs after leds_setup(), which covers the rest.
-static __code const struct { uint16_t reg; uint32_t val; } custom_init_regs[] = {
-	{ RTL837X_REG_LED3_0_SET1,   0x00100000UL },
-	{ RTL837X_REG_LED1_0_SET1,   0x01400155UL },
-	{ RTL837X_REG_LED1_0_SET0,   0x01740141UL },
-	{ RTL837X_REG_LED_GLB_IO_EN, 0x7f24977fUL },
-	{ RTL837X_PIN_MUX_0,         0x20db6880UL },
-};
-
-void machine_custom_init(void) __banked
-{
-	uint8_t i;
-	// REG_SET is a multi-statement macro without a do-while wrapper: braces required
-	for (i = 0; i < sizeof(custom_init_regs) / sizeof(custom_init_regs[0]); i++) {
-		REG_SET(custom_init_regs[i].reg, custom_init_regs[i].val);
-	}
-}
-
-#elif defined MACHINE_PCB_SWTG024AS_A_2_0_1
-void machine_custom_init(void) __banked
-{
-    reg_bit_set(RTL837X_REG_LED_GLB_IO_EN, 6);
-    reg_bit_set(RTL837X_REG_LED_MODE, 17);
-    reg_bit_clear(RTL837X_REG_LED_MODE, 9);
-    reg_bit_clear(RTL837X_REG_LED_MODE, 7);
-}
-
-#elif defined(MACHINE_SWTG024AS_A_2_0_1_5C_1SFP) || \
-      defined(MACHINE_SWTG024AS_V2_0)
-void machine_custom_init(void) __banked
-{
-    uint16_t pval;
-
-    reg_bit_set(RTL837X_REG_LED_GLB_IO_EN, 6);
-    reg_bit_set(RTL837X_REG_LED_MODE, 17);
-    reg_bit_clear(RTL837X_REG_LED_MODE, 9);
-    reg_bit_clear(RTL837X_REG_LED_MODE, 7);
-
-    // OEM firmware sets these companion SDS0 polarity bits for the RTL8221B.
-    sds_read(0, 0, 0);
-    pval = SFR_DATA_U16;
-    sds_write_v(0, 0, 0, pval | 0x100);
-
-    sds_read(0, 6, 2);
-    pval = SFR_DATA_U16;
-    sds_write_v(0, 6, 2, pval | 0x4000);
-}
-
-#elif defined MACHINE_ZX310S_4T2XT
-void machine_custom_init(void) __banked
-{
-	// For this device, the reset value of RTL837X_PIN_MUX_0 is 0x30000000,
-	// which would disables all LEDS, enable them manually:
-	REG_SET(RTL837X_PIN_MUX_0, 0x30db68bf);
-}
-
-#elif defined MACHINE_FG_4GT_2SX_V2_0
-void machine_custom_init(void) __banked
-{
-	REG_SET(RTL837X_REG_LED_GLB_IO_EN, 0x7624155b);
-}
-
-#else
-void machine_custom_init(void) __banked { }
-#endif
diff --git a/rtl837x_igmp.c b/rtl837x_igmp.c
index 35940446..f996cd3f 100644
--- a/rtl837x_igmp.c
+++ b/rtl837x_igmp.c
@@ -126,7 +126,7 @@ void igmp_setup(void) __banked
 	 * For now the IGMP protocols are flooded (01), MLD which MAC-based is handled by ASIC
 	 * All messages are allowed and maximum MC group is 0xff
 	 */
-	for (i = machine.min_port; i <= machine.max_port; i++)
+	for (i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++)
 		REG_SET(RTL837X_IGMP_PORT_CFG + (i << 2), IGMP_MAX_GROUP | IGMP_PROTOCOL_ENABLE | IGMP_FLOOD);
 
 /*	// Allow all physical ports to be dynamic router ports
@@ -155,7 +155,7 @@ void igmp_enable(void) __banked
 
 	// Configure per-port IGMP configuration, bits 0-10 enable MC protocol snooping,
 	// bits 16-24 configure max MC group used by that port. Trap to CPU (10)
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		REG_SET(RTL837X_IGMP_PORT_CFG + (i << 2), IGMP_MAX_GROUP | IGMP_PROTOCOL_ENABLE | IGMP_TRAP);
 	}
 }
@@ -180,7 +180,7 @@ void igmp_router_port_set(uint16_t pmask) __banked
 void igmp_show(void) __banked
 {
 	print_string("igmp_show called\n");
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		write_char('0' + i); write_char(':');
 		reg_read_m(RTL837X_IGMP_PORT_CFG + (i << 2));
 		print_sfr_data();
diff --git a/rtl837x_init.c b/rtl837x_init.c
index c7b7e71e..73498642 100644
--- a/rtl837x_init.c
+++ b/rtl837x_init.c
@@ -246,7 +246,7 @@ void rtl8372_init(void) __banked
 	// [...]
 	///
 	uint16_t reg = 0x1238 + 0x300; // Port base register for the bits we set
-	for (char i = machine.min_port; i <= machine.max_port; i++) {
+	for (char i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		// Bit 7 (0x40) enables replacement of the RTL-VLAN tag with an 802.1Q VLAN tag
 		REG_SET(reg, 0xe77);
 		reg += 0x100;
diff --git a/rtl837x_lacp.c b/rtl837x_lacp.c
index 2573bc34..c8d6b1d6 100644
--- a/rtl837x_lacp.c
+++ b/rtl837x_lacp.c
@@ -165,7 +165,7 @@ void lacp_mux_update(void) __banked
 		if (!lacp_lag_ports[lag])
 			continue;
 		lacp_scratch_mask = 0;
-		for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+		for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 			if (lacp_port_lag[i] != lag)
 				continue;
 			if ((lacp_actor_state[i] & LACP_STATE_FULL) == LACP_STATE_FULL
@@ -248,7 +248,7 @@ void lacp_in(void) __banked
 		return;
 
 	port = ((uint8_t)HTONS(LACP_H->rtl_tag.pmask)) & 0x0f;
-	if (port < machine.min_port || port > machine.max_port)
+	if (!MACHINE_PORT_VALID(port))
 		return;
 
 	lag = lacp_port_lag[port];
@@ -298,7 +298,7 @@ void lacp_in(void) __banked
 
 static void lacp_step(void)
 {
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		if (lacp_port_lag[i] == LACP_LAG_NONE)
 			continue;
 
@@ -328,7 +328,7 @@ static void lacp_step(void)
 
 		if (!lacp_agg_valid[lag])
 			continue;
-		for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+		for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 			if (lacp_port_lag[i] == lag && lacp_rx_state[i] == LACP_RX_CURRENT
 			    && lacp_sys_eq(lacp_partner_sys[i], lacp_agg_sys[lag])) {
 				any_current = 1;
@@ -422,7 +422,7 @@ void lacp_lag_set(uint8_t lag, __xdata uint16_t ports) __banked
 		return;
 	lacp_scratch_flag = lacp_any_lag();
 
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		if (lacp_port_lag[i] == lag && !(ports & PORT_BIT(i))) {
 			lacp_port_lag[i] = LACP_LAG_NONE;
 			lacp_port_release(i);
@@ -438,7 +438,7 @@ void lacp_lag_set(uint8_t lag, __xdata uint16_t ports) __banked
 	if (ports && !lacp_scratch_flag)
 		lacp_engine_on();
 
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		if (!(ports & PORT_BIT(i)))
 			continue;
 		lacp_scratch_lag = lacp_port_lag[i];
@@ -490,7 +490,7 @@ void lacp_show(void) __banked
 		print_string(" members "); print_short(lacp_members_last[l]); write_char('\n');
 	}
 
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		print_string("port "); print_byte(machine.log_to_phys_port[i]);
 		print_string(" actor "); print_byte(lacp_actor_state[i]);
 		print_string(" partner "); print_byte(lacp_partner_state[i]);
diff --git a/rtl837x_leds.c b/rtl837x_leds.c
index d1b8cf91..5757060c 100644
--- a/rtl837x_leds.c
+++ b/rtl837x_leds.c
@@ -37,10 +37,10 @@ void leds_setup(void) __banked
 
 	// Set up all Port-LEDs to belong to RLDP
 	sfr_data[3] = sfr_data[2] = sfr_data[1] = sfr_data[0] = 0;
-	for (uint8_t i = machine.min_port; i <= (machine.max_port > 7 ? 7 : machine.max_port); i++)
+	for (uint8_t i = MACHINE_MIN_PORT; i <= (MACHINE_MAX_PORT > 7 ? 7 : MACHINE_MAX_PORT); i++)
 		sfr_data[3 - (i >> 2)] |= i & 1 ? 0xf0 : 0x0f;
 	reg_write_m(RTL837X_REG_LED_RLDP_2);
-	if (machine.max_port == 8)
+	if (MACHINE_MAX_PORT == 8)
 		REG_SET(RTL837X_REG_LED_RLDP_3, 0x0000000f);	// Port 8
 
 	// Configure high LEDs 27-29: mux and LED enable
@@ -110,7 +110,7 @@ void leds_setup(void) __banked
 	
 	// Configure the LED-set of a port
 	sfr_data[3] = sfr_data[2] = sfr_data[1] = sfr_data[0] = 0;
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++)
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++)
 		sfr_data[3 - (i >> 2)] |= machine.port_led_set[i] << ((i & 3) << 1);
 	reg_write_m(RTL837X_LED_PORT_SET_SEL);
 
diff --git a/rtl837x_leds_dump.c b/rtl837x_leds_dump.c
index 8a820e3a..5bf04d0f 100644
--- a/rtl837x_leds_dump.c
+++ b/rtl837x_leds_dump.c
@@ -87,7 +87,7 @@ void leds_dump(void) __banked
 		}
 		write_char('\n');
 	}
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		reg_read_m(RTL837X_LED_PORT_SET_SEL);
 		__xdata uint8_t set = sfr_data[3 - (i >> 2)];
 		set = (set >> ((i & 3) << 1));
diff --git a/rtl837x_lldp.c b/rtl837x_lldp.c
index 84208433..441e7eb4 100644
--- a/rtl837x_lldp.c
+++ b/rtl837x_lldp.c
@@ -108,7 +108,7 @@ void lldp_send(void) __banked __reentrant
      */
     uip_len = MAC_ADDR_LEN + MAC_ADDR_LEN + sizeof(struct rtl_tag) + LLDP_ETHERTYPE_LENGTH + (p - LLDP_O->payload);
 
-    for (uint8_t port = machine.min_port; port <= machine.max_port; port++) {
+    for (uint8_t port = MACHINE_MIN_PORT; port <= MACHINE_MAX_PORT; port++) {
 
         if ((1 << port) & lldp_logical_port_status) {
             LLDP_O->payload[port_position] = '0' + machine.log_to_phys_port[port];
diff --git a/rtl837x_port.c b/rtl837x_port.c
index d4a5b9f5..6874685f 100644
--- a/rtl837x_port.c
+++ b/rtl837x_port.c
@@ -271,7 +271,7 @@ void vlan_setup(void) __banked
 	wait_table_ready();
 
 	// Set PVID 1 for every port. TODO: Skip unused ports!
-	for (uint8_t i = machine.min_port; i <= machine.max_port + 1; i++) {  // Do this also for the CPU port (+1)
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT + 1; i++) {  // Do this also for the CPU port (+1)
 		uint16_t reg = RTL837x_PVID_BASE_REG + ((i >> 1) << 2);
 #ifdef DEBUG
 		print_byte(i); write_char(':'); write_char(' '); print_short(reg); write_char('=');
@@ -459,7 +459,7 @@ void port_l2_setup(void) __banked
 
 	port_l2_forget();
 
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		// Limit the number of automatically learned MAC-Entries per port to 0x1040
 		uint8_t idx = (i << 2);
 		REG_SET(RTL837X_L2_LRN_PORT_CONSTRAINT + idx, 0x00001040);
@@ -511,7 +511,7 @@ void port_media_show(uint8_t port) __banked
 void port_stats_print(void) __banked
 {
 	print_string("\nPort\tState\tLink\tTxGood\t\tTxBad\t\tRxGood\t\tRxBad\t\tMACs\n");
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		print_phys_port(i); write_char('\t');
 
 		if (!machine.is_sfp[i]) {
@@ -594,14 +594,14 @@ void port_stats_print(void) __banked
 
 void port_isolate(uint8_t port, __xdata uint16_t pmask) __banked
 {
-	if (port <= machine.max_port)
+	if (port <= MACHINE_MAX_PORT)
 		REG_SET(RTL837X_PORT_ISOLATION_BASE + (port << 2), pmask);
 }
 
 
 uint16_t port_isolation_get(uint8_t port) __banked
 {
-	if (port > machine.max_port)
+	if (port > MACHINE_MAX_PORT)
 		return 0;
 
 	reg_read_m(RTL837X_PORT_ISOLATION_BASE + (port << 2));
@@ -775,7 +775,7 @@ void port_eee_status(uint8_t port) __banked
 
 void port_eee_enable_all(__xdata uint8_t speed) __banked
 {
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		if (i == 3 && machine.n_10g) {
 			port_eee_enable(i, speed);
 		} else if (i == 8 && machine.n_10g == 2) {
@@ -792,7 +792,7 @@ void port_eee_enable_all(__xdata uint8_t speed) __banked
 
 void port_eee_disable_all(void) __banked
 {
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		port_eee_disable(i);
 	}
 }
@@ -800,7 +800,7 @@ void port_eee_disable_all(void) __banked
 
 void port_eee_status_all(void) __banked
 {
-	for (uint8_t i = machine.min_port; i <= machine.max_port; i++) {
+	for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		port_eee_status(i);
 	}
 }
@@ -908,7 +908,7 @@ void vlan_dump(void) __banked
 {
 	print_string("Ingress VLAN configuration:\n");
 	print_string("Port\tPVID\tType\tFiltering\n");
-	for (uint8_t port = machine.min_port; port <= machine.max_port; port++) {
+	for (uint8_t port = MACHINE_MIN_PORT; port <= MACHINE_MAX_PORT; port++) {
 		print_vlan_ingress_port(port);
 	}
 	print_vlan_ingress_port(9);
@@ -923,7 +923,7 @@ void vlan_dump(void) __banked
 /** Set the ingress VLAN filtering */
 bool port_ingress_vlan_filter_set(uint8_t port, __xdata bool enabled) __banked
 {
-	if (port < machine.min_port || (port > machine.max_port && port != CPU_PORT)) {
+	if (!MACHINE_PORT_VALID(port) && port != CPU_PORT) {
 		return false;
 	}
 	if (enabled)
@@ -937,7 +937,7 @@ bool port_ingress_vlan_filter_set(uint8_t port, __xdata bool enabled) __banked
 /** Get the ingress VLAN filtering status */
 bool port_ingress_vlan_filter_get(uint8_t port) __banked
 {
-	if (port < machine.min_port || (port > machine.max_port && port != CPU_PORT)) {
+	if (!MACHINE_PORT_VALID(port) && port != CPU_PORT) {
 		return false;
 	}
 
diff --git a/rtl837x_storm.c b/rtl837x_storm.c
index 2308b210..23cfc83a 100644
--- a/rtl837x_storm.c
+++ b/rtl837x_storm.c
@@ -67,7 +67,7 @@ void storm_show(void) __banked
 {
 	uint8_t i, t, idx;
 
-	for (i = machine.min_port; i <= machine.max_port; i++) {
+	for (i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++) {
 		print_string("port ");
 		write_char('0' + machine.log_to_phys_port[i]);
 		for (t = 0; t < STORM_TYPES; t++) {
diff --git a/rtl837x_stp.c b/rtl837x_stp.c
index bc810d96..118e265c 100644
--- a/rtl837x_stp.c
+++ b/rtl837x_stp.c
@@ -335,7 +335,7 @@ static uint8_t stp_ent_active(uint8_t e) __reentrant
 		return 0;
 	if (e >= STP_LAG_BASE)
 		return stp_lag_mask[e - STP_LAG_BASE] != 0;
-	return e >= machine.min_port && e <= machine.max_port && stp_ent_of[e] == e;
+	return MACHINE_PORT_VALID(e) && stp_ent_of[e] == e;
 }
 
 
@@ -410,7 +410,7 @@ static void stp_topology_change(uint8_t port) __reentrant
 	stp_tc_count++;
 	stp_tc_while = ((uint16_t)stp_maxage_s + stp_fwddelay_s) * STP_HZ;
 	if (port >= STP_LAG_BASE) {
-		for (uint8_t i = machine.min_port; i <= machine.max_port; i++)
+		for (uint8_t i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++)
 			if (stp_ent_has(port, i))
 				port_l2_forget_port(i);
 	} else {
@@ -565,7 +565,7 @@ void stp_in(void) __banked
 
 	/* Ingress port: low nibble of the CPU tag's pmask on RX */
 	stp_scratch = ((uint8_t)HTONS(STP_H->rtl_tag.pmask)) & 0x0f;
-	if (stp_scratch < machine.min_port || stp_scratch > machine.max_port)
+	if (!MACHINE_PORT_VALID(stp_scratch))
 		return;
 	port = stp_ent_of[stp_scratch];
 
@@ -658,7 +658,7 @@ void stp_in(void) __banked
 		if (!stp_tc_while) {
 			uint8_t i;
 			stp_tc_count++;
-			for (i = machine.min_port; i <= machine.max_port; i++)
+			for (i = MACHINE_MIN_PORT; i <= MACHINE_MAX_PORT; i++)
 				if (!stp_ent_has(port, i)
 				    && (stp_pflags[stp_ent_of[i]] & STP_PF_ENABLED)
 				    && !(stp_pflags[stp_ent_of[i]] & STP_PF_OPEREDGE))
@@ -714,7 +714,7 @@ void stp_timers(void) __banked
 		if (stp_map_dirty) {
 			stp_map_dirty = 0;
 			for (stp_i = 0; stp_i < STP_LAG_BASE; stp_i++) {
-				if (stp_i < machine.min_port || stp_i > machine.max_port)
+				if (!MACHINE_PORT_VALID(stp_i))
 					continue;
 				if (stp_ent_of[stp_i] != stp_i) {
 					stp_loop_held[stp_i] = 0;
@@ -747,14 +747,14 @@ void stp_timers(void) __banked
 		{
 			__xdata static uint16_t eff;
 			eff = 0;
-			for (stp_i = machine.min_port; stp_i <= machine.max_port; stp_i++)
+			for (stp_i = MACHINE_MIN_PORT; stp_i <= MACHINE_MAX_PORT; stp_i++)
 				if ((stp_link_now >> stp_i) & 1)
 					eff |= (uint16_t)1 << stp_ent_of[stp_i];
 			stp_link_now = eff;
 		}
 		if (stp_link_now != stp_link_prev) {
 			for (stp_i = 0; stp_i < STP_ENTITIES; stp_i++) {
-				if (stp_i < STP_PORTS && (stp_i < machine.min_port || stp_i > machine.max_port))
+				if (stp_i < STP_PORTS && !MACHINE_PORT_VALID(stp_i))
 					continue;
 				if (stp_i < STP_PORTS && stp_ent_of[stp_i] != stp_i)
 					continue;
@@ -890,7 +890,7 @@ static void stp_fdb_update(__xdata uint16_t pmask)
 			continue;
 		port_l2mc_set(0x00, stp_fdb_vid, pmask);
 	}
-	for (stp_fdb_i = machine.min_port; stp_fdb_i <= machine.max_port; stp_fdb_i++) {
+	for (stp_fdb_i = MACHINE_MIN_PORT; stp_fdb_i <= MACHINE_MAX_PORT; stp_fdb_i++) {
 		stp_fdb_vid = port_pvid_get(stp_fdb_i);
 		port_l2mc_set(0x00, stp_fdb_vid, pmask);
 	}
@@ -910,7 +910,7 @@ void stp_setup(void) __banked
 		stp_tx_count[stp_i] = 0;
 		port_timers[stp_i] = 0;
 		port_hello[stp_i] = (uint16_t)stp_hello_s * STP_HZ;
-		if (stp_i < STP_PORTS && (stp_i < machine.min_port || stp_i > machine.max_port))
+		if (stp_i < STP_PORTS && !MACHINE_PORT_VALID(stp_i))
 			continue;
 		if (stp_i >= STP_LAG_BASE && !stp_lag_mask[stp_i - STP_LAG_BASE])
 			continue;
@@ -939,7 +939,7 @@ void stp_setup(void) __banked
 	reg_read_m(RTL837X_REG_LINKS_STS);
 	stp_link_now = (uint16_t)sfr_data[1] | ((uint16_t)sfr_data[2] << 8);
 	stp_link_prev = 0;
-	for (stp_i = machine.min_port; stp_i <= machine.max_port; stp_i++)
+	for (stp_i = MACHINE_MIN_PORT; stp_i <= MACHINE_MAX_PORT; stp_i++)
 		if ((stp_link_now >> stp_i) & 1)
 			stp_link_prev |= (uint16_t)1 << stp_ent_of[stp_i];
 
@@ -952,7 +952,7 @@ void stp_setup(void) __banked
 void stp_off(void) __banked
 {
 	sfr_data[0] = sfr_data[1] = sfr_data[2] = sfr_data[3] = 0;
-	for (stp_i = machine.min_port; stp_i <= machine.max_port; stp_i++) {
+	for (stp_i = MACHINE_MIN_PORT; stp_i <= MACHINE_MAX_PORT; stp_i++) {
 		// Set STP port state to forwarding
 		// States are: 00 disable, 01 blocking, 10 learning, 11 forwarding
 		sfr_data[3 - (stp_i >> 2)] |= (uint8_t)(STP_ST_FORWARDING << ((stp_i << 1) & 0x7));
diff --git a/rtlplayground.c b/rtlplayground.c
index 0afa93c8..fbb94d76 100644
--- a/rtlplayground.c
+++ b/rtlplayground.c
@@ -1203,7 +1203,7 @@ static void handle_tick(void)
 		lacp_timers();
 	health_phase(HEALTH_PH_STP);
 	lldp_tick();
-	health_phase(HEALTH_LLDP);
+	health_phase(HEALTH_PH_LLDP);
 	cabletest_tick();
 }
 
diff --git a/test/env_tables.c b/test/env_tables.c
index 719e045a..e4d23c37 100644
--- a/test/env_tables.c
+++ b/test/env_tables.c
@@ -59,8 +59,6 @@ uint8_t *hex = (uint8_t *)hex_chars;
 /* ---- a 9-port RTL8373 whose logical ports map to themselves ---- */
 const struct machine machine = {
 	.machine_name = "HOSTTEST",
-	.min_port = 0,
-	.max_port = 8,
 	.n_sfp = 0,
 	.log_to_phys_port = { 1, 2, 3, 4, 5, 6, 7, 8, 9 },
 	.phys_to_log_port = { 0, 1, 2, 3, 4, 5, 6, 7, 8 },
diff --git a/test/test_lacp.c b/test/test_lacp.c
index 160c773e..56b8e56f 100644
--- a/test/test_lacp.c
+++ b/test/test_lacp.c
@@ -14,8 +14,11 @@
 uint8_t uip_buf[UIP_CONF_BUFFER_ALLOC_SIZE];
 uint16_t uip_len;
 struct uip_eth_addr uip_ethaddr = { .addr = {0x02,0x11,0x22,0x33,0x44,0x55} };
-const struct machine machine = { .min_port = 0, .max_port = 7,
+const struct machine machine = {
 			   .log_to_phys_port = {5, 1, 2, 3, 4, 6, 7, 8, 9} };
+/* Logical ports of the mock machine above */
+#define TEST_MIN_PORT 0
+#define TEST_MAX_PORT 7
 struct machine_runtime machine_detected = { .isRTL8373 = 1 };
 uint8_t lacpEnabled;
 uint16_t management_vlan;	/* mocked; slow-protocol path zeroes it per-frame */
@@ -216,7 +219,7 @@ int main(int argc, char **argv)
 	lacp_lag_set(0, 0x00ff);
 	step(8);
 	int all_tx = 1, sane = 1;
-	for (int i = machine.min_port; i <= machine.max_port; i++) {
+	for (int i = TEST_MIN_PORT; i <= TEST_MAX_PORT; i++) {
 		if (!tx_count[i]) all_tx = 0;
 		if (last_tx[i].ethertype != HTONS(0x8809) || last_tx[i].subtype != 1
 		    || last_tx[i].dst[5] != 0x02
diff --git a/tools/Makefile b/tools/Makefile
index 1b1c6685..80ac9743 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -1,6 +1,8 @@
 CC = gcc
 CCFLAGS = -Wall -o
-BUILDDIR = output
+ifndef BUILDDIR
+	BUILDDIR = output
+endif
 
 all: create_build_dir $(BUILDDIR)/injector $(BUILDDIR)/fileadder $(BUILDDIR)/httpd_sim\
 	$(BUILDDIR)/crc_calculator $(BUILDDIR)/imagebuilder
diff --git a/tools/bank_occupancy.sh b/tools/bank_occupancy.sh
new file mode 100755
index 00000000..8638d390
--- /dev/null
+++ b/tools/bank_occupancy.sh
@@ -0,0 +1,31 @@
+#!/bin/bash
+MACHINE="$1"
+if [[ ! -s output-main/rtlplayground.map ]]; then
+    original_branch=$(git branch --show-current)
+    #trap 'git switch "$original_branch"' EXIT
+    git switch main && make CI=1 MACHINE="$MACHINE" BUILDDIR=output-main
+    git switch "$original_branch"
+fi
+source <(sed -rn 's/^([XCD]SEG|(BANK[0-9])).*=\s+([0-9]+)\. bytes.*$/main_\1=\3/p' output-main/rtlplayground.map | sort -u)
+
+main_WEB=$(du -sb output-main/html_min | awk '{print $1}')
+if [[ ! -s "output/$MACHINE/rtlplayground.map" ]]; then
+    make CI=1 MACHINE="$MACHINE"
+fi
+source <(sed -rn 's/^([XCD]SEG|(BANK[0-9])).*=\s+([0-9]+)\. bytes.*$/branch_\1=\3/p' output/"$MACHINE"/rtlplayground.map | sort -u)
+branch_WEB=$(du -sb output/html_min | awk '{print $1}')
+
+print_line() {
+  local name=$1 main=$2 branch=$3
+  printf '%-20s %-20s %-20s %-20s\n' "$name" "$main" "$branch" "$((branch - main))"
+}
+
+printf '%-20s %-20s %-20s %-20s\n' "segment" "main" "branch" "change"
+
+print_line "BANK1" "$main_BANK1" "$branch_BANK1"
+print_line "BANK2" "$main_BANK2" "$branch_BANK2"
+print_line "BANK3" "$main_BANK3" "$branch_BANK3"
+print_line "CSEG" "$main_CSEG" "$branch_CSEG"
+print_line "DSEG" "$main_DSEG" "$branch_DSEG"
+print_line "XSEG" "$main_XSEG" "$branch_XSEG"
+print_line "WEB" "$main_WEB" "$branch_WEB"