From 58fddeb74f9215a7d7c8ff8dd935727cbdf0e5d8 Mon Sep 17 00:00:00 2001
From: David Woodhouse <dwmw2@infradead.org>
Date: Thu, 11 Dec 2025 22:53:03 +0900
Subject: [PATCH] Optimize get_config_hash to avoid repeated snprintf calls

Check if hash string is already formatted before calling snprintf,
since static variables in BSS are zero-initialized.
---
 esphome/core/buildinfo.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/esphome/core/buildinfo.cpp b/esphome/core/buildinfo.cpp
index 839bee9857..dd07fa6f6c 100644
--- a/esphome/core/buildinfo.cpp
+++ b/esphome/core/buildinfo.cpp
@@ -34,7 +34,9 @@ static uintptr_t build_time = (uintptr_t) &ESPHOME_BUILD_TIME;
 
 const char *get_config_hash() {
   static char hash_str[9];
-  snprintf(hash_str, sizeof(hash_str), "%08x", (uint32_t) config_hash);
+  if (!hash_str[0]) {
+    snprintf(hash_str, sizeof(hash_str), "%08x", (uint32_t) config_hash);
+  }
   return hash_str;
 }