From 21c7900444e2e3ecad9fafdf5266aadf0ba9b8ce Mon Sep 17 00:00:00 2001
From: Ian Gulliver <github@flamingcow.io>
Date: Sun, 12 Apr 2026 08:27:21 +0900
Subject: [PATCH] Watchdog timer, boot reason tracking, net_poll frame limit,
 reboot/picoboot CLI commands

---
 firmware/firmware.cpp       |  1 +
 firmware/include/handlers.h |  1 +
 firmware/include/wire.h     |  1 +
 firmware/lib/handlers.cpp   | 21 +++++++++++++++------
 firmware/lib/net.cpp        |  2 +-
 firmware/test.cpp           |  1 +
 lib/client/types.go         |  7 +++++--
 7 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/firmware/firmware.cpp b/firmware/firmware.cpp
index 1779f94..a622e1b 100644
--- a/firmware/firmware.cpp
+++ b/firmware/firmware.cpp
@@ -15,5 +15,6 @@ static constexpr handler_entry handlers[] = {
 int main() {
     handlers_init();
     dispatch_init();
+    handlers_start();
     dispatch_run(handlers);
 }
diff --git a/firmware/include/handlers.h b/firmware/include/handlers.h
index d75be63..776fda3 100644
--- a/firmware/include/handlers.h
+++ b/firmware/include/handlers.h
@@ -7,6 +7,7 @@
 extern std::string_view firmware_name;
 
 void handlers_init();
+void handlers_start();
 std::optional<ResponsePICOBOOT> handle_picoboot(const responder& resp, const RequestPICOBOOT&);
 std::optional<ResponseInfo> handle_info(const responder& resp, const RequestInfo&);
 std::optional<ResponseLog> handle_log(const responder& resp, const RequestLog&);
diff --git a/firmware/include/wire.h b/firmware/include/wire.h
index 5f42521..5d58808 100644
--- a/firmware/include/wire.h
+++ b/firmware/include/wire.h
@@ -47,6 +47,7 @@ struct RequestInfo {
 enum class boot_reason : uint8_t {
     cold_boot = 0,
     request_reboot = 1,
+    watchdog = 2,
 };
 
 struct ResponseInfo {
diff --git a/firmware/lib/handlers.cpp b/firmware/lib/handlers.cpp
index 3acff80..ea10442 100644
--- a/firmware/lib/handlers.cpp
+++ b/firmware/lib/handlers.cpp
@@ -9,16 +9,25 @@
 
 static constexpr uint32_t XIP_BASE_ADDR = 0x10000000;
 static constexpr uint32_t FLASH_SIZE = 2 * 1024 * 1024;
-static constexpr uint32_t REBOOT_MAGIC = 0x504D5242;
-
 static boot_reason detected_boot_reason;
 
+static void poke_watchdog() {
+    watchdog_update();
+    dispatch_schedule_ms(500, poke_watchdog);
+}
+
 void handlers_init() {
-    if (watchdog_hw->scratch[0] == REBOOT_MAGIC)
-        detected_boot_reason = boot_reason::request_reboot;
+    auto val = static_cast<boot_reason>(watchdog_hw->scratch[0]);
+    if (val == boot_reason::request_reboot || val == boot_reason::watchdog)
+        detected_boot_reason = val;
     else
         detected_boot_reason = boot_reason::cold_boot;
-    watchdog_hw->scratch[0] = 0;
+    watchdog_hw->scratch[0] = static_cast<uint32_t>(boot_reason::watchdog);
+    watchdog_enable(1000, true);
+}
+
+void handlers_start() {
+    poke_watchdog();
 }
 
 std::optional<ResponsePICOBOOT> handle_picoboot(const responder&, const RequestPICOBOOT&) {
@@ -80,7 +89,7 @@ std::optional<ResponseFlashWrite> handle_flash_write(const responder&, const Req
 
 std::optional<ResponseReboot> handle_reboot(const responder&, const RequestReboot&) {
     dispatch_schedule_ms(100, []{
-        watchdog_hw->scratch[0] = REBOOT_MAGIC;
+        watchdog_hw->scratch[0] = static_cast<uint32_t>(boot_reason::request_reboot);
         watchdog_reboot(0, 0, 0);
     });
     return ResponseReboot{};
diff --git a/firmware/lib/net.cpp b/firmware/lib/net.cpp
index fb38e98..089ac0e 100644
--- a/firmware/lib/net.cpp
+++ b/firmware/lib/net.cpp
@@ -140,7 +140,7 @@ void net_poll(std::span<uint8_t> tx) {
     w6300::irq_pending = false;
     w6300::clear_interrupt(w6300::ik_int_all);
     static uint8_t rx_buf[1518];
-    while (w6300::get_socket_recv_buf(raw_socket) > 0) {
+    for (int i = 0; i < 16 && w6300::get_socket_recv_buf(raw_socket) > 0; i++) {
         auto result = w6300::recv(raw_socket, std::span{rx_buf});
         if (!result) break;
         span_writer tx_writer(tx);
diff --git a/firmware/test.cpp b/firmware/test.cpp
index 5a30c25..9b576f8 100644
--- a/firmware/test.cpp
+++ b/firmware/test.cpp
@@ -27,6 +27,7 @@ static constexpr handler_entry handlers[] = {
 int main() {
     handlers_init();
     dispatch_init();
+    handlers_start();
 
     gpio_init(LED_PIN);
     gpio_set_dir(LED_PIN, GPIO_OUT);
diff --git a/lib/client/types.go b/lib/client/types.go
index 6dc3e5e..b564206 100644
--- a/lib/client/types.go
+++ b/lib/client/types.go
@@ -9,8 +9,9 @@ type RequestInfo struct{}
 type BootReason uint8
 
 const (
-	BootCold    BootReason = 0
-	BootReboot  BootReason = 1
+	BootCold     BootReason = 0
+	BootReboot   BootReason = 1
+	BootWatchdog BootReason = 2
 )
 
 func (b BootReason) String() string {
@@ -19,6 +20,8 @@ func (b BootReason) String() string {
 		return "cold"
 	case BootReboot:
 		return "reboot"
+	case BootWatchdog:
+		return "watchdog"
 	default:
 		return "unknown"
 	}