From e88c9ba0661131f39d5ee3c9de77a6e48204b4c5 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Wed, 18 Mar 2026 07:47:42 -1000
Subject: [PATCH] [core] Inline progmem_read functions on non-ESP8266 platforms
 (#14913)

---
 esphome/components/esp32/core.cpp     | 3 ---
 esphome/components/host/core.cpp      | 3 ---
 esphome/components/libretiny/core.cpp | 3 ---
 esphome/components/rp2040/core.cpp    | 7 -------
 esphome/components/zephyr/core.cpp    | 3 ---
 esphome/core/hal.h                    | 9 +++++++++
 6 files changed, 9 insertions(+), 19 deletions(-)

diff --git a/esphome/components/esp32/core.cpp b/esphome/components/esp32/core.cpp
index cba25bca2b..83bd09b643 100644
--- a/esphome/components/esp32/core.cpp
+++ b/esphome/components/esp32/core.cpp
@@ -53,9 +53,6 @@ void arch_init() {
 }
 void HOT arch_feed_wdt() { esp_task_wdt_reset(); }
 
-uint8_t progmem_read_byte(const uint8_t *addr) { return *addr; }
-const char *progmem_read_ptr(const char *const *addr) { return *addr; }
-uint16_t progmem_read_uint16(const uint16_t *addr) { return *addr; }
 uint32_t arch_get_cpu_cycle_count() { return esp_cpu_get_cycle_count(); }
 uint32_t arch_get_cpu_freq_hz() {
   uint32_t freq = 0;
diff --git a/esphome/components/host/core.cpp b/esphome/components/host/core.cpp
index d5c61ec986..a662e842ee 100644
--- a/esphome/components/host/core.cpp
+++ b/esphome/components/host/core.cpp
@@ -58,9 +58,6 @@ void HOT arch_feed_wdt() {
   // pass
 }
 
-uint8_t progmem_read_byte(const uint8_t *addr) { return *addr; }
-const char *progmem_read_ptr(const char *const *addr) { return *addr; }
-uint16_t progmem_read_uint16(const uint16_t *addr) { return *addr; }
 uint32_t arch_get_cpu_cycle_count() {
   struct timespec spec;
   clock_gettime(CLOCK_MONOTONIC, &spec);
diff --git a/esphome/components/libretiny/core.cpp b/esphome/components/libretiny/core.cpp
index 6bb2d9dcc1..1cfe68e924 100644
--- a/esphome/components/libretiny/core.cpp
+++ b/esphome/components/libretiny/core.cpp
@@ -54,9 +54,6 @@ void arch_restart() {
 void HOT arch_feed_wdt() { lt_wdt_feed(); }
 uint32_t arch_get_cpu_cycle_count() { return lt_cpu_get_cycle_count(); }
 uint32_t arch_get_cpu_freq_hz() { return lt_cpu_get_freq(); }
-uint8_t progmem_read_byte(const uint8_t *addr) { return *addr; }
-const char *progmem_read_ptr(const char *const *addr) { return *addr; }
-uint16_t progmem_read_uint16(const uint16_t *addr) { return *addr; }
 
 }  // namespace esphome
 
diff --git a/esphome/components/rp2040/core.cpp b/esphome/components/rp2040/core.cpp
index 7079cbca15..b7a9000612 100644
--- a/esphome/components/rp2040/core.cpp
+++ b/esphome/components/rp2040/core.cpp
@@ -37,13 +37,6 @@ void arch_init() {
 
 void HOT arch_feed_wdt() { watchdog_update(); }
 
-uint8_t progmem_read_byte(const uint8_t *addr) {
-  return pgm_read_byte(addr);  // NOLINT
-}
-const char *progmem_read_ptr(const char *const *addr) {
-  return reinterpret_cast<const char *>(pgm_read_ptr(addr));  // NOLINT
-}
-uint16_t progmem_read_uint16(const uint16_t *addr) { return *addr; }
 uint32_t HOT arch_get_cpu_cycle_count() { return ulMainGetRunTimeCounterValue(); }
 uint32_t arch_get_cpu_freq_hz() { return RP2040::f_cpu(); }
 
diff --git a/esphome/components/zephyr/core.cpp b/esphome/components/zephyr/core.cpp
index 1d105a1057..d7c77fdd2c 100644
--- a/esphome/components/zephyr/core.cpp
+++ b/esphome/components/zephyr/core.cpp
@@ -59,9 +59,6 @@ void arch_feed_wdt() {
 void arch_restart() { sys_reboot(SYS_REBOOT_COLD); }
 uint32_t arch_get_cpu_cycle_count() { return k_cycle_get_32(); }
 uint32_t arch_get_cpu_freq_hz() { return sys_clock_hw_cycles_per_sec(); }
-uint8_t progmem_read_byte(const uint8_t *addr) { return *addr; }
-const char *progmem_read_ptr(const char *const *addr) { return *addr; }
-uint16_t progmem_read_uint16(const uint16_t *addr) { return *addr; }
 
 Mutex::Mutex() {
   auto *mutex = new k_mutex();
diff --git a/esphome/core/hal.h b/esphome/core/hal.h
index c2c9b1a325..03a30b7459 100644
--- a/esphome/core/hal.h
+++ b/esphome/core/hal.h
@@ -41,8 +41,17 @@ void arch_init();
 void arch_feed_wdt();
 uint32_t arch_get_cpu_cycle_count();
 uint32_t arch_get_cpu_freq_hz();
+
+#ifdef USE_ESP8266
+// ESP8266: pgm_read_* does real flash reads on Harvard architecture
 uint8_t progmem_read_byte(const uint8_t *addr);
 const char *progmem_read_ptr(const char *const *addr);
 uint16_t progmem_read_uint16(const uint16_t *addr);
+#else
+// All other platforms: PROGMEM is a no-op, so these are direct dereferences
+inline uint8_t progmem_read_byte(const uint8_t *addr) { return *addr; }
+inline const char *progmem_read_ptr(const char *const *addr) { return *addr; }
+inline uint16_t progmem_read_uint16(const uint16_t *addr) { return *addr; }
+#endif
 
 }  // namespace esphome