From 9a353cc3e22f07eb0d7c485e008d5fe5d050ae07 Mon Sep 17 00:00:00 2001
From: Omni Flux <omniflux@omniflux.com>
Date: Thu, 6 Aug 2026 17:05:54 -0600
Subject: [PATCH] [logger] Make boot log buffer log level configurable

(cherry picked from commit 7f532b3021999bb75551368ca13966b729a89011)
---
 esphome/components/logger/__init__.py | 7 ++++++-
 esphome/components/logger/logger.cpp  | 2 +-
 esphome/components/logger/logger.h    | 4 ++--
 esphome/core/defines.h                | 1 +
 4 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/esphome/components/logger/__init__.py b/esphome/components/logger/__init__.py
index ee81ef80cce..bc29e2eec15 100644
--- a/esphome/components/logger/__init__.py
+++ b/esphome/components/logger/__init__.py
@@ -106,6 +106,7 @@ USB_CDC = "USB_CDC"
 DEFAULT = "DEFAULT"
 
 CONF_BOOT_LOG_BUFFER_SIZE = "boot_log_buffer_size"
+CONF_BOOT_LOG_LEVEL = "boot_log_level"
 CONF_INITIAL_LEVEL = "initial_level"
 CONF_LOGGER_ID = "logger_id"
 CONF_ESP8266_STORE_LOG_STRINGS_IN_FLASH = "esp8266_store_log_strings_in_flash"
@@ -273,6 +274,7 @@ CONFIG_SCHEMA = cv.All(
                     cv.int_range(min=512, max=16384),
                 ),
             ),
+            cv.Optional(CONF_BOOT_LOG_LEVEL, default="WARN"): is_log_level,
             cv.SplitDefault(
                 CONF_TASK_LOG_BUFFER_SIZE,
                 esp32=768,  # Default: 768 bytes (~5-6 messages with 70-byte text plus thread names)
@@ -385,11 +387,14 @@ async def to_code(config: ConfigType) -> None:
     if task_log_buffer_size > 0:
         cg.add_define("USE_ESPHOME_TASK_LOG_BUFFER")
         cg.add_define("ESPHOME_TASK_LOG_BUFFER_SIZE", task_log_buffer_size)
-    # Boot log buffer captures early WARN/ERROR lines for later replay
+    # Boot log buffer captures early lines for later replay
     # (logger.replay_boot_logs action). Buffer is a direct member of Logger.
     if (boot_log_buffer_size := config[CONF_BOOT_LOG_BUFFER_SIZE]) > 0:
         cg.add_define("USE_LOGGER_BOOT_LOG_BUFFER")
         cg.add_define("ESPHOME_LOGGER_BOOT_LOG_BUFFER_SIZE", boot_log_buffer_size)
+        cg.add_build_flag(
+            f"-DESPHOME_LOGGER_BOOT_LOG_LEVEL={LOG_LEVELS[config[CONF_BOOT_LOG_LEVEL]]}"
+        )
     log = cg.new_Pvariable(
         config[CONF_ID],
         baud_rate,
diff --git a/esphome/components/logger/logger.cpp b/esphome/components/logger/logger.cpp
index 5dfe77a7c93..9ab793d267b 100644
--- a/esphome/components/logger/logger.cpp
+++ b/esphome/components/logger/logger.cpp
@@ -209,7 +209,7 @@ void Logger::process_messages_() {
 static constexpr uint16_t BOOT_LOG_RECORD_HEADER_SIZE = 2 + 1 + 4 + sizeof(const char *);
 
 void Logger::boot_log_capture_(uint8_t level, const char *tag, const LogBuffer &buf) {
-  if (this->boot_log_done_ || level > ESPHOME_LOG_LEVEL_WARN || level == ESPHOME_LOG_LEVEL_NONE)
+  if (this->boot_log_done_ || level > ESPHOME_LOGGER_BOOT_LOG_LEVEL || level == ESPHOME_LOG_LEVEL_NONE)
     return;
   // Strip the leading ANSI color prefix and trailing reset; the replay adds its own around the stamp.
   const char *text = buf.data;
diff --git a/esphome/components/logger/logger.h b/esphome/components/logger/logger.h
index 1a0ba84f9fe..013806b9825 100644
--- a/esphome/components/logger/logger.h
+++ b/esphome/components/logger/logger.h
@@ -179,7 +179,7 @@ class Logger final : public Component {
 #endif
   uint8_t get_log_level() { return this->current_level_; }
 
-  /// Re-emit WARN/ERROR messages captured during boot through the normal log
+  /// Re-emit messages captured during boot through the normal log
   /// dispatch so connected listeners (API, MQTT, ...) can see them. Stops
   /// further capture; safe to call multiple times. Warns when the logger was
   /// built without 'boot_log_buffer_size'.
@@ -396,7 +396,7 @@ class Logger final : public Component {
   // Large buffers placed last to keep frequently-accessed member offsets small
   char tx_buffer_[ESPHOME_LOGGER_TX_BUFFER_SIZE + 1];  // +1 for null terminator
 #ifdef USE_LOGGER_BOOT_LOG_BUFFER
-  // Sequential records of early WARN/ERROR lines: u16 text_len | u8 level | u32 millis | const char *tag | text
+  // Sequential records of early lines: u16 text_len | u8 level | u32 millis | const char *tag | text
   char boot_log_buffer_[ESPHOME_LOGGER_BOOT_LOG_BUFFER_SIZE];
 #endif
 #ifdef USE_ESPHOME_TASK_LOG_BUFFER
diff --git a/esphome/core/defines.h b/esphome/core/defines.h
index 6442291572f..7b3f640f2fa 100644
--- a/esphome/core/defines.h
+++ b/esphome/core/defines.h
@@ -41,6 +41,7 @@
 #define ESPHOME_LOG_MAX_LISTENERS 8
 #define USE_LOGGER_BOOT_LOG_BUFFER
 #define ESPHOME_LOGGER_BOOT_LOG_BUFFER_SIZE 4096
+#define ESPHOME_LOGGER_BOOT_LOG_LEVEL ESPHOME_LOG_LEVEL_WARN
 
 // Feature flags
 #define USE_ALARM_CONTROL_PANEL