feat(esp_system): Adds Kconfigs to place code in IRAM

Author: KonstantinKondrashov

components/esp_system/Kconfig

@@ -9,6 +9,25 @@ menu "ESP System Settings"
 
     orsource "./port/soc/$IDF_TARGET/Kconfig.tracemem"
 
+    config ESP_SYSTEM_IN_IRAM
+        bool "Place system functions in IRAM" if SPI_FLASH_AUTO_SUSPEND
+        default y
+        help
+            The following system functions will be placed in IRAM if this option is enabled:
+            - system startup
+            - system time
+            - system error
+            - system restart
+            - system crosscore
+            - system debug
+            - system APB backup DMA lock
+            - system application tick hook
+            - Unified Behavior Sanitizer (UBSAN) hook
+            - Interrupt watchdog handler
+            - XTAL32K watchdog timer
+            - USB CDC functions for the esp_rom_printf (if ESP_CONSOLE_USB_CDC_SUPPORT_ETS_PRINTF=y)
+            - IPC and IPC ISR
+
     choice ESP_SYSTEM_PANIC
         prompt "Panic handler behaviour"
         default ESP_SYSTEM_PANIC_PRINT_REBOOT
@@ -635,6 +654,11 @@ endmenu  # ESP System Settings
 
 menu "IPC (Inter-Processor Call)"
 
+    config ESP_IPC_ENABLE
+        bool
+        default y
+        depends on !ESP_SYSTEM_SINGLE_CORE_MODE || APPTRACE_GCOV_ENABLE
+
     config ESP_IPC_TASK_STACK_SIZE
         int "Inter-Processor Call (IPC) task stack size"
         range 512 65536 if !APPTRACE_ENABLE
@@ -651,7 +675,7 @@ menu "IPC (Inter-Processor Call)"
     config ESP_IPC_USES_CALLERS_PRIORITY
         bool "IPC runs at caller's priority"
         default y
-        depends on !FREERTOS_UNICORE
+        depends on ESP_IPC_ENABLE
         help
             If this option is not enabled then the IPC task will keep behavior same as prior to that of ESP-IDF v4.0,
             hence IPC task will run at (configMAX_PRIORITIES - 1) priority.

components/esp_system/crosscore_int.c

@@ -5,7 +5,7 @@
  */
 #include "sdkconfig.h"
 #include <stdint.h>
-#include "esp_attr.h"
+#include "esp_private/esp_system_attr.h"
 #include "esp_err.h"
 #include "esp_cpu.h"
 #include "esp_intr_alloc.h"
@@ -34,12 +34,12 @@ static volatile uint32_t reason[CONFIG_FREERTOS_NUMBER_OF_CORES];
 ToDo: There is a small chance the CPU already has yielded when this ISR is serviced. In that case, it's running the intended task but
 the ISR will cause it to switch _away_ from it. portYIELD_FROM_ISR will probably just schedule the task again, but have to check that.
 */
-static inline void IRAM_ATTR esp_crosscore_isr_handle_yield(void)
+static inline void ESP_SYSTEM_IRAM_ATTR esp_crosscore_isr_handle_yield(void)
 {
     portYIELD_FROM_ISR();
 }
 
-static void IRAM_ATTR esp_crosscore_isr(void *arg)
+static void ESP_SYSTEM_IRAM_ATTR esp_crosscore_isr(void *arg)
 {
     uint32_t my_reason_val;
     //A pointer to the correct reason array item is passed to this ISR.
@@ -93,19 +93,23 @@ void esp_crosscore_int_init(void)
     reason[esp_cpu_get_core_id()] = 0;
     portEXIT_CRITICAL(&reason_spinlock);
     esp_err_t err __attribute__((unused)) = ESP_OK;
+    int flags = 0;
+#if CONFIG_ESP_SYSTEM_IN_IRAM
+    flags |= ESP_INTR_FLAG_IRAM;
+#endif
 #if CONFIG_FREERTOS_NUMBER_OF_CORES > 1
     if (esp_cpu_get_core_id() == 0) {
-        err = esp_intr_alloc(SYS_CPU_INTR_FROM_CPU_0_SOURCE, ESP_INTR_FLAG_IRAM, esp_crosscore_isr, (void*)&reason[0], NULL);
+        err = esp_intr_alloc(SYS_CPU_INTR_FROM_CPU_0_SOURCE, flags, esp_crosscore_isr, (void*)&reason[0], NULL);
     } else {
-        err = esp_intr_alloc(SYS_CPU_INTR_FROM_CPU_1_SOURCE, ESP_INTR_FLAG_IRAM, esp_crosscore_isr, (void*)&reason[1], NULL);
+        err = esp_intr_alloc(SYS_CPU_INTR_FROM_CPU_1_SOURCE, flags, esp_crosscore_isr, (void*)&reason[1], NULL);
     }
 #else
-    err = esp_intr_alloc(SYS_CPU_INTR_FROM_CPU_0_SOURCE, ESP_INTR_FLAG_IRAM, esp_crosscore_isr, (void*)&reason[0], NULL);
+    err = esp_intr_alloc(SYS_CPU_INTR_FROM_CPU_0_SOURCE, flags, esp_crosscore_isr, (void*)&reason[0], NULL);
 #endif
     ESP_ERROR_CHECK(err);
 }
 
-static void IRAM_ATTR esp_crosscore_int_send(int core_id, uint32_t reason_mask)
+static void ESP_SYSTEM_IRAM_ATTR esp_crosscore_int_send(int core_id, uint32_t reason_mask)
 {
     assert(core_id < CONFIG_FREERTOS_NUMBER_OF_CORES);
     //Mark the reason we interrupt the other CPU
@@ -116,28 +120,28 @@ static void IRAM_ATTR esp_crosscore_int_send(int core_id, uint32_t reason_mask)
     crosscore_int_ll_trigger_interrupt(core_id);
 }
 
-void IRAM_ATTR esp_crosscore_int_send_yield(int core_id)
+void ESP_SYSTEM_IRAM_ATTR esp_crosscore_int_send_yield(int core_id)
 {
     esp_crosscore_int_send(core_id, REASON_YIELD);
 }
 
-void IRAM_ATTR esp_crosscore_int_send_freq_switch(int core_id)
+void ESP_SYSTEM_IRAM_ATTR esp_crosscore_int_send_freq_switch(int core_id)
 {
     esp_crosscore_int_send(core_id, REASON_FREQ_SWITCH);
 }
 
-void IRAM_ATTR esp_crosscore_int_send_gdb_call(int core_id)
+void ESP_SYSTEM_IRAM_ATTR esp_crosscore_int_send_gdb_call(int core_id)
 {
     esp_crosscore_int_send(core_id, REASON_GDB_CALL);
 }
 
-void IRAM_ATTR esp_crosscore_int_send_print_backtrace(int core_id)
+void ESP_SYSTEM_IRAM_ATTR esp_crosscore_int_send_print_backtrace(int core_id)
 {
     esp_crosscore_int_send(core_id, REASON_PRINT_BACKTRACE);
 }
 
 #if CONFIG_ESP_TASK_WDT_EN
-void IRAM_ATTR esp_crosscore_int_send_twdt_abort(int core_id)
+void ESP_SYSTEM_IRAM_ATTR esp_crosscore_int_send_twdt_abort(int core_id)
 {
     esp_crosscore_int_send(core_id, REASON_TWDT_ABORT);
 }

components/esp_system/esp_ipc.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -12,7 +12,7 @@
 #include "esp_err.h"
 #include "esp_ipc.h"
 #include "esp_private/esp_ipc_isr.h"
-#include "esp_attr.h"
+#include "esp_private/esp_system_attr.h"
 #include "esp_cpu.h"
 
 #include "freertos/FreeRTOS.h"
@@ -21,7 +21,7 @@
 
 #define IPC_MAX_PRIORITY (configMAX_PRIORITIES - 1)
 
-#if !defined(CONFIG_FREERTOS_UNICORE) || defined(CONFIG_APPTRACE_GCOV_ENABLE)
+#if CONFIG_ESP_IPC_ENABLE
 
 #if CONFIG_COMPILER_OPTIMIZATION_NONE
 #define IPC_STACK_SIZE (CONFIG_ESP_IPC_TASK_STACK_SIZE + 0x100)
@@ -49,7 +49,7 @@ static volatile esp_ipc_func_t s_no_block_func[portNUM_PROCESSORS] = { 0 };
 static volatile bool s_no_block_func_and_arg_are_ready[portNUM_PROCESSORS] = { 0 };
 static void * volatile s_no_block_func_arg[portNUM_PROCESSORS];
 
-static void IRAM_ATTR ipc_task(void* arg)
+static void ESP_SYSTEM_IRAM_ATTR ipc_task(void* arg)
 {
     const int cpuid = (int) arg;
 
@@ -198,4 +198,4 @@ esp_err_t esp_ipc_call_nonblocking(uint32_t cpu_id, esp_ipc_func_t func, void* a
     return ESP_FAIL;
 }
 
-#endif // !defined(CONFIG_FREERTOS_UNICORE) || defined(CONFIG_APPTRACE_GCOV_ENABLE)
+#endif // CONFIG_ESP_IPC_ENABLE

components/esp_system/fp_unwind.c

@@ -6,6 +6,7 @@
 
 #include "sdkconfig.h"
 #include <string.h>
+#include "esp_private/esp_system_attr.h"
 #include "esp_private/panic_internal.h"
 #include "esp_memory_utils.h"
 #include "riscv/libunwind-riscv.h"
@@ -52,7 +53,7 @@ static inline bool esp_fp_ptr_is_data(void* ptr)
  *
  * @returns Number of entries filled in the array.
  */
-uint32_t IRAM_ATTR esp_fp_get_callers(uint32_t frame, void** callers, void** stacks, uint32_t depth)
+uint32_t ESP_SYSTEM_IRAM_ATTR esp_fp_get_callers(uint32_t frame, void** callers, void** stacks, uint32_t depth)
 {
     uint32_t written = 0;
     uint32_t pc = 0;

components/esp_system/freertos_hooks.c

@@ -27,7 +27,7 @@ static portMUX_TYPE hooks_spinlock = portMUX_INITIALIZER_UNLOCKED;
 static esp_freertos_idle_cb_t idle_cb[CONFIG_FREERTOS_NUMBER_OF_CORES][MAX_HOOKS] = {0};
 static esp_freertos_tick_cb_t tick_cb[CONFIG_FREERTOS_NUMBER_OF_CORES][MAX_HOOKS] = {0};
 
-void IRAM_ATTR esp_vApplicationTickHook(void)
+void esp_vApplicationTickHook(void)
 {
     int n;
     int core = xPortGetCoreID();

components/esp_system/include/esp_private/esp_system_attr.h

@@ -0,0 +1,24 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#include "esp_attr.h"
+#include "sdkconfig.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if CONFIG_ESP_SYSTEM_IN_IRAM
+#define ESP_SYSTEM_IRAM_ATTR IRAM_ATTR
+#else
+#define ESP_SYSTEM_IRAM_ATTR
+#endif
+
+#ifdef __cplusplus
+}
+#endif

components/esp_system/int_wdt.c

@@ -17,7 +17,7 @@
 #include "esp_cpu.h"
 #include "esp_check.h"
 #include "esp_err.h"
-#include "esp_attr.h"
+#include "esp_private/esp_system_attr.h"
 #include "esp_log.h"
 #include "esp_intr_alloc.h"
 #include "esp_chip_info.h"
@@ -101,7 +101,7 @@ extern uint32_t _lx_intr_livelock_counter, _lx_intr_livelock_max;
 volatile bool int_wdt_cpu1_ticked = false;
 #endif
 
-static void IRAM_ATTR tick_hook(void)
+static void ESP_SYSTEM_IRAM_ATTR tick_hook(void)
 {
 #if CONFIG_ESP_INT_WDT_CHECK_CPU1
     if (esp_cpu_get_core_id() != 0) {

components/esp_system/linker.lf

@@ -12,33 +12,52 @@ entries:
             hw_stack_guard:esp_hw_stack_guard_get_fired_cpu (noflash)
             hw_stack_guard:esp_hw_stack_guard_get_pc (noflash)
 
-    esp_err (noflash)
-    esp_system_chip:esp_system_abort (noflash)
-    ubsan (noflash)
-
-    if ESP_CONSOLE_USB_CDC_SUPPORT_ETS_PRINTF:
-        usb_console:esp_usb_console_write_char (noflash)
-        usb_console:esp_usb_console_write_buf (noflash)
-        usb_console:esp_usb_console_flush_internal (noflash)
-        usb_console:esp_usb_console_osglue_wait_proc (noflash)
-        usb_console:esp_usb_console_osglue_dis_int (noflash)
-        usb_console:esp_usb_console_osglue_ena_int (noflash)
-        usb_console:esp_usb_console_interrupt (noflash)
-        usb_console:esp_usb_console_poll_interrupts (noflash)
-        usb_console:esp_usb_console_cdc_acm_cb (noflash)
-        usb_console:esp_usb_console_dfu_detach_cb (noflash)
-        usb_console:esp_usb_console_before_restart (noflash)
-        usb_console:esp_usb_console_on_restart_timeout (noflash)
+    # These functions are called when the cache is disabled
+    system_internal:esp_restart_noos (noflash)
+    system_internal:esp_system_reset_modules_on_exit (noflash)
+
+    if ESP_PANIC_HANDLER_IRAM = y || ESP_BROWNOUT_USE_INTR = y:
+        reset_reason:esp_reset_reason_set_hint (noflash)
+
+    # It may be called very frequently, so place it in IRAM to avoid performance degradation
+    freertos_hooks:esp_vApplicationTickHook (noflash)
+
+    if ESP_SYSTEM_IN_IRAM = y:
+        esp_err (noflash)
+        esp_system_chip:esp_system_abort (noflash)
+        panic:panic_abort (noflash)
+        if IDF_TARGET_ESP32 = y:
+            esp_system_chip:esp_restart_noos_dig (noflash)
+        system_time:esp_system_get_time (noflash)
+        system_time:esp_system_get_time_resolution (noflash)
+        ubsan (noflash)
+        if COMPILER_STACK_CHECK = y:
+            stack_check:__stack_chk_fail (noflash)
+
+        if ESP_CONSOLE_USB_CDC_SUPPORT_ETS_PRINTF:
+            usb_console:esp_usb_console_write_char (noflash)
+            usb_console:esp_usb_console_write_buf (noflash)
+            usb_console:esp_usb_console_flush_internal (noflash)
+            usb_console:esp_usb_console_osglue_wait_proc (noflash)
+            usb_console:esp_usb_console_osglue_dis_int (noflash)
+            usb_console:esp_usb_console_osglue_ena_int (noflash)
+            usb_console:esp_usb_console_interrupt (noflash)
+            usb_console:esp_usb_console_poll_interrupts (noflash)
+            usb_console:esp_usb_console_cdc_acm_cb (noflash)
+            usb_console:esp_usb_console_dfu_detach_cb (noflash)
+            usb_console:esp_usb_console_before_restart (noflash)
+            usb_console:esp_usb_console_on_restart_timeout (noflash)
 
     if APP_BUILD_TYPE_RAM = n:
         image_process (noflash)
 
 [mapping:vfs_cdcacm]
 archive: libvfs.a
 entries:
-    if ESP_CONSOLE_USB_CDC_SUPPORT_ETS_PRINTF:
-        vfs_cdcacm:cdcacm_tx_cb (noflash)
-        vfs_cdcacm:cdcacm_rx_cb (noflash)
+    if ESP_SYSTEM_IN_IRAM = y:
+        if ESP_CONSOLE_USB_CDC_SUPPORT_ETS_PRINTF:
+            vfs_cdcacm:cdcacm_tx_cb (noflash)
+            vfs_cdcacm:cdcacm_rx_cb (noflash)
 
 [mapping:esp_system_hal]
 archive: libhal.a

components/esp_system/panic.c

@@ -463,7 +463,7 @@ void esp_panic_handler(panic_info_t *info)
 #endif /* CONFIG_ESP_SYSTEM_PANIC_GDBSTUB */
 }
 
-void IRAM_ATTR __attribute__((noreturn, no_sanitize_undefined)) panic_abort(const char *details)
+void __attribute__((noreturn, no_sanitize_undefined)) panic_abort(const char *details)
 {
     g_panic_abort = true;
     g_panic_abort_details = (char *) details;
@@ -490,11 +490,11 @@ void IRAM_ATTR __attribute__((noreturn, no_sanitize_undefined)) panic_abort(cons
  * If these weren't provided, reset reason code would be linked into the app
  * even if the app never called esp_reset_reason().
  */
-void IRAM_ATTR __attribute__((weak)) esp_reset_reason_set_hint(esp_reset_reason_t hint)
+void __attribute__((weak)) esp_reset_reason_set_hint(esp_reset_reason_t hint)
 {
 }
 
-esp_reset_reason_t IRAM_ATTR  __attribute__((weak)) esp_reset_reason_get_hint(void)
+esp_reset_reason_t __attribute__((weak)) esp_reset_reason_get_hint(void)
 {
     return ESP_RST_UNKNOWN;
 }

components/esp_system/port/arch/riscv/debug_helpers.c

@@ -11,7 +11,7 @@
 #include "freertos/task.h"
 #include "esp_private/freertos_debug.h"
 #include "esp_err.h"
-#include "esp_attr.h"
+#include "esp_private/esp_system_attr.h"
 #include "esp_private/esp_cpu_internal.h"
 #include <string.h>
 
@@ -36,7 +36,7 @@ extern void panic_print_registers(const void *frame, int core);
     * exit this handler as fast as possible, then we will simply print
     * the interruptee's registers.
     */
-esp_err_t IRAM_ATTR esp_backtrace_print(int depth)
+esp_err_t ESP_SYSTEM_IRAM_ATTR esp_backtrace_print(int depth)
 {
     (void)depth;