Copy rc_switch table entries out of flash with progmem_memcpy

Codegen now calls rc_switch_protocol(index) instead of copying RC_SWITCH_PROTOCOLS[index] by value, so the ESP8266 copy path never byte loads from the PROGMEM table. Document the keyed slot_counter in AGENTS.md.

AGENTS.md

@@ -629,6 +629,9 @@ file does, and it is the authority when they disagree. The most useful starting
                _request_listener_slot()
                cg.add(hub.register_listener(var))
            ```
+           When several instances each own a list declared at the same size (one per hub of a
+           `MULTI_CONF` component), pass the owning object as the key, `_request_listener_slot(str(hub))`;
+           the define is then the largest count any one key requested instead of the total.
            ```cpp
            #ifdef MY_COMPONENT_LISTENER_COUNT
              void register_listener(MyComponentListener *listener);

esphome/components/remote_base/__init__.py

@@ -1535,7 +1535,7 @@ def validate_rc_switch_raw_code(value):
 
 def build_rc_switch_protocol(config):
     if isinstance(config, int):
-        return rc_switch_protocols[config]
+        return rc_switch_protocol(config)
     pl = config[CONF_PULSE_LENGTH]
     return RCSwitchBase(
         config[CONF_SYNC][0] * pl,
@@ -1622,7 +1622,7 @@ RC_SWITCH_TRANSMITTER = cv.Schema(
     }
 )
 
-rc_switch_protocols = ns.RC_SWITCH_PROTOCOLS
+rc_switch_protocol = ns.rc_switch_protocol
 RCSwitchData = ns.struct("RCSwitchData")
 RCSwitchBase = ns.class_("RCSwitchBase")
 RCSwitchTrigger = ns.class_("RCSwitchTrigger", RemoteReceiverTrigger)

esphome/components/remote_base/rc_switch_protocol.cpp

@@ -1,12 +1,19 @@
 #include "rc_switch_protocol.h"
 
 #include <iterator>
+#include "esphome/core/hal.h"
 #include "esphome/core/log.h"
 
 namespace esphome::remote_base {
 
 static const char *const TAG = "remote.rc_switch";
 
+RCSwitchBase rc_switch_protocol(uint8_t index) {
+  RCSwitchBase protocol;
+  progmem_memcpy(&protocol, &RC_SWITCH_PROTOCOLS[index], sizeof(protocol));
+  return protocol;
+}
+
 void RCSwitchBase::one(RemoteTransmitData *dst) const {
   if (!this->inverted_) {
     dst->mark(this->one_high_);

esphome/components/remote_base/rc_switch_protocol.h

@@ -68,8 +68,9 @@ class RCSwitchBase {
   uint32_t inverted_{};  // bool widened so every field is a word: the table is read from flash
 };
 
-// Constant-initialized and kept in flash on every platform; ESP8266 reads it in place, which only
-// works while every field is a whole word
+// Constant-initialized and kept in flash on every platform. The decoder reads entries in place
+// through a pointer, which ESP8266 only allows while every field is a whole word; copies out of
+// the table go through rc_switch_protocol()
 static_assert(sizeof(RCSwitchBase) == 7 * sizeof(uint32_t), "RCSwitchBase must stay word-only for flash reads");
 inline constexpr RCSwitchBase RC_SWITCH_PROTOCOLS[] PROGMEM = {
     {0, 0, 0, 0, 0, 0, false},
@@ -83,6 +84,10 @@ inline constexpr RCSwitchBase RC_SWITCH_PROTOCOLS[] PROGMEM = {
     {250, 2500, 250, 1250, 250, 250, false},
 };
 
+/// RAM copy of RC_SWITCH_PROTOCOLS[index] for the transmit actions and the dumper, made with
+/// progmem_memcpy so no byte load ever touches the flash table on ESP8266
+RCSwitchBase rc_switch_protocol(uint8_t index);
+
 uint64_t decode_binary_string(const std::string &data);
 
 uint64_t decode_binary_string_mask(const std::string &data);