fix(ram_app): Fixed issue ram_app can't use the SPI Flash

1st bootloader won't help to initialize the MSPI & cache properly as it
usually do when loading from flash. And the ram app doesn't have valid
headers.

Since there is no enough space in 2nd bootloader, we replace the
`bootloader_init_spi_flash` in the ram_app (!pure_ram_app), with an
customized alternative of it for the ram_app.

This alternative helps to initialize the MSPI & cache properly, without
the help of 1st bootloader or image headers.

components/bootloader_support/bootloader_flash/include/bootloader_flash_config.h

@@ -58,6 +58,7 @@ void bootloader_flash_clock_config(const esp_image_header_t* pfhdr);
  */
 void bootloader_flash_gpio_config(const esp_image_header_t* pfhdr);
 
+#ifdef CONFIG_IDF_TARGET_ESP32
 /**
  * @brief Configure SPI flash read dummy based on different mode and frequency.
  *
@@ -66,6 +67,10 @@ void bootloader_flash_gpio_config(const esp_image_header_t* pfhdr);
  * @return None
  */
 void bootloader_flash_dummy_config(const esp_image_header_t* pfhdr);
+#else
+// The meaning has changed on this chip. Deprecated, Call `bootloader_configure_spi_pins()` and `bootloader_flash_set_dummy_out()` directly.
+void bootloader_flash_dummy_config(const esp_image_header_t* pfhdr) __attribute__((deprecated));
+#endif
 
 #ifdef CONFIG_IDF_TARGET_ESP32
 /**

components/bootloader_support/bootloader_flash/include/esp_private/bootloader_flash_internal.h

@@ -18,6 +18,15 @@ extern "C" {
  */
 esp_err_t bootloader_init_spi_flash(void);
 
+#if CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+/**
+ * @brief Config all flash related stuff according to the header. The consistency of all flash configs is ensured.
+ *
+ * @return None
+ */
+void bootloader_flash_hardware_init(void);
+#endif
+
 #ifdef __cplusplus
 }
 #endif

components/bootloader_support/bootloader_flash/src/bootloader_flash_config_esp32.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2018-2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2018-2023 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -16,6 +16,7 @@
 #include "soc/gpio_periph.h"
 #include "soc/efuse_reg.h"
 #include "soc/spi_reg.h"
+#include "soc/dport_reg.h"
 #include "soc/soc_caps.h"
 #include "soc/soc_pins.h"
 #include "soc/chip_revision.h"
@@ -354,6 +355,7 @@ static void print_flash_info(const esp_image_header_t *bootloader_hdr)
     ESP_EARLY_LOGI(TAG, "SPI Flash Size : %s", str);
 }
 
+
 static void IRAM_ATTR bootloader_init_flash_configure(void)
 {
     bootloader_flash_gpio_config(&bootloader_image_hdr);
@@ -384,3 +386,87 @@ esp_err_t bootloader_init_spi_flash(void)
     bootloader_enable_wp();
     return ESP_OK;
 }
+
+
+#if CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+static void bootloader_flash_set_spi_mode(const esp_image_header_t* pfhdr)
+{
+    esp_rom_spiflash_read_mode_t mode;
+    switch(pfhdr->spi_mode) {
+    case ESP_IMAGE_SPI_MODE_QIO:
+        mode = ESP_ROM_SPIFLASH_QIO_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_QOUT:
+        mode = ESP_ROM_SPIFLASH_QOUT_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_DIO:
+        mode = ESP_ROM_SPIFLASH_DIO_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_FAST_READ:
+        mode = ESP_ROM_SPIFLASH_FASTRD_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_SLOW_READ:
+        mode = ESP_ROM_SPIFLASH_SLOWRD_MODE;
+        break;
+    default:
+        mode = ESP_ROM_SPIFLASH_DIO_MODE;
+    }
+    esp_rom_spiflash_config_readmode(mode);
+}
+
+void bootloader_flash_hardware_init(void)
+{
+    esp_rom_spiflash_attach(esp_rom_efuse_get_flash_gpio_info(), false);
+
+    // reset MMU
+    /* completely reset MMU in case serial bootloader was running */
+    Cache_Read_Disable(0);
+#if !CONFIG_FREERTOS_UNICORE
+    Cache_Read_Disable(1);
+#endif
+    Cache_Flush(0);
+#if !CONFIG_FREERTOS_UNICORE
+    Cache_Flush(1);
+#endif
+    mmu_init(0);
+#if !CONFIG_FREERTOS_UNICORE
+    /* The lines which manipulate DPORT_APP_CACHE_MMU_IA_CLR bit are
+        necessary to work around a hardware bug. */
+    DPORT_REG_SET_BIT(DPORT_APP_CACHE_CTRL1_REG, DPORT_APP_CACHE_MMU_IA_CLR);
+    mmu_init(1);
+    DPORT_REG_CLR_BIT(DPORT_APP_CACHE_CTRL1_REG, DPORT_APP_CACHE_MMU_IA_CLR);
+#endif
+
+    /* normal ROM boot exits with DROM0 cache unmasked,
+        but serial bootloader exits with it masked. */
+    DPORT_REG_CLR_BIT(DPORT_PRO_CACHE_CTRL1_REG, DPORT_PRO_CACHE_MASK_DROM0);
+#if !CONFIG_FREERTOS_UNICORE
+    DPORT_REG_CLR_BIT(DPORT_APP_CACHE_CTRL1_REG, DPORT_APP_CACHE_MASK_DROM0);
+#endif
+
+    // update flash ID
+    bootloader_flash_update_id();
+    // Check and run XMC startup flow
+    esp_err_t ret = bootloader_flash_xmc_startup();
+    assert(ret == ESP_OK);
+
+    /* Alternative of bootloader_init_spi_flash */
+    // RAM app doesn't have headers in the flash. Make a default one for it.
+    esp_image_header_t WORD_ALIGNED_ATTR hdr = {
+        .spi_mode = ESP_IMAGE_SPI_MODE_DIO,
+        .spi_speed = ESP_IMAGE_SPI_SPEED_DIV_2,
+        .spi_size = ESP_IMAGE_FLASH_SIZE_2MB,
+    };
+    bootloader_flash_set_spi_mode(&hdr);
+    bootloader_flash_clock_config(&hdr);
+    bootloader_flash_gpio_config(&hdr);
+    bootloader_flash_dummy_config(&hdr);
+    bootloader_flash_cs_timing_config();
+
+    /* Remaining parts in bootloader_init_spi_flash */
+    bootloader_flash_unlock();
+    update_flash_config(&hdr);
+    //ensure the flash is write-protected
+    bootloader_enable_wp();
+}
+#endif //CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP

components/bootloader_support/bootloader_flash/src/bootloader_flash_config_esp32c2.c

@@ -71,6 +71,7 @@ void IRAM_ATTR bootloader_flash_set_dummy_out(void)
     REG_SET_BIT(SPI_MEM_CTRL_REG(1), SPI_MEM_FDUMMY_OUT | SPI_MEM_D_POL | SPI_MEM_Q_POL);
 }
 
+//deprecated
 void IRAM_ATTR bootloader_flash_dummy_config(const esp_image_header_t *pfhdr)
 {
     bootloader_configure_spi_pins(1);
@@ -220,7 +221,8 @@ static void bootloader_print_mmu_page_size(void)
 
 static void IRAM_ATTR bootloader_init_flash_configure(void)
 {
-    bootloader_flash_dummy_config(&bootloader_image_hdr);
+    bootloader_configure_spi_pins(1);
+    bootloader_flash_set_dummy_out();
     bootloader_flash_cs_timing_config();
 }
 
@@ -248,3 +250,67 @@ esp_err_t bootloader_init_spi_flash(void)
     bootloader_enable_wp();
     return ESP_OK;
 }
+
+#if CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+static void bootloader_flash_set_spi_mode(const esp_image_header_t* pfhdr)
+{
+    esp_rom_spiflash_read_mode_t mode;
+    switch(pfhdr->spi_mode) {
+    case ESP_IMAGE_SPI_MODE_QIO:
+        mode = ESP_ROM_SPIFLASH_QIO_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_QOUT:
+        mode = ESP_ROM_SPIFLASH_QOUT_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_DIO:
+        mode = ESP_ROM_SPIFLASH_DIO_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_FAST_READ:
+        mode = ESP_ROM_SPIFLASH_FASTRD_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_SLOW_READ:
+        mode = ESP_ROM_SPIFLASH_SLOWRD_MODE;
+        break;
+    default:
+        mode = ESP_ROM_SPIFLASH_DIO_MODE;
+    }
+    esp_rom_spiflash_config_readmode(mode);
+}
+
+void bootloader_flash_hardware_init(void)
+{
+    esp_rom_spiflash_attach(0, false);
+
+    //init cache hal
+    cache_hal_init();
+    //init mmu
+    mmu_hal_init();
+    // update flash ID
+    bootloader_flash_update_id();
+
+    /* Alternative of bootloader_init_spi_flash */
+    // RAM app doesn't have headers in the flash. Make a default one for it.
+    esp_image_header_t WORD_ALIGNED_ATTR hdr = {
+        .spi_mode = ESP_IMAGE_SPI_MODE_DIO,
+        .spi_speed = ESP_IMAGE_SPI_SPEED_DIV_2,
+        .spi_size = ESP_IMAGE_FLASH_SIZE_2MB,
+    };
+    bootloader_configure_spi_pins(1);
+    bootloader_flash_set_spi_mode(&hdr);
+    bootloader_flash_clock_config(&hdr);
+    bootloader_flash_set_dummy_out();
+    bootloader_flash_cs_timing_config();
+
+    bootloader_spi_flash_resume();
+    bootloader_flash_unlock();
+
+    bootloader_print_mmu_page_size();
+
+    cache_hal_disable(CACHE_TYPE_ALL);
+    update_flash_config(&hdr);
+    cache_hal_enable(CACHE_TYPE_ALL);
+
+    //ensure the flash is write-protected
+    bootloader_enable_wp();
+}
+#endif //CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP

components/bootloader_support/bootloader_flash/src/bootloader_flash_config_esp32c3.c

@@ -75,6 +75,7 @@ void IRAM_ATTR bootloader_flash_set_dummy_out(void)
     REG_SET_BIT(SPI_MEM_CTRL_REG(1), SPI_MEM_FDUMMY_OUT | SPI_MEM_D_POL | SPI_MEM_Q_POL);
 }
 
+//deprecated
 void IRAM_ATTR bootloader_flash_dummy_config(const esp_image_header_t *pfhdr)
 {
     bootloader_configure_spi_pins(1);
@@ -222,7 +223,8 @@ static void print_flash_info(const esp_image_header_t *bootloader_hdr)
 
 static void IRAM_ATTR bootloader_init_flash_configure(void)
 {
-    bootloader_flash_dummy_config(&bootloader_image_hdr);
+    bootloader_configure_spi_pins(1);
+    bootloader_flash_set_dummy_out();
     bootloader_flash_cs_timing_config();
 }
 
@@ -256,3 +258,69 @@ esp_err_t bootloader_init_spi_flash(void)
     bootloader_enable_wp();
     return ESP_OK;
 }
+
+#if CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+static void bootloader_flash_set_spi_mode(const esp_image_header_t* pfhdr)
+{
+    esp_rom_spiflash_read_mode_t mode;
+    switch(pfhdr->spi_mode) {
+    case ESP_IMAGE_SPI_MODE_QIO:
+        mode = ESP_ROM_SPIFLASH_QIO_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_QOUT:
+        mode = ESP_ROM_SPIFLASH_QOUT_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_DIO:
+        mode = ESP_ROM_SPIFLASH_DIO_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_FAST_READ:
+        mode = ESP_ROM_SPIFLASH_FASTRD_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_SLOW_READ:
+        mode = ESP_ROM_SPIFLASH_SLOWRD_MODE;
+        break;
+    default:
+        mode = ESP_ROM_SPIFLASH_DIO_MODE;
+    }
+    esp_rom_spiflash_config_readmode(mode);
+}
+
+void bootloader_flash_hardware_init(void)
+{
+    esp_rom_spiflash_attach(esp_rom_efuse_get_flash_gpio_info(), false);
+
+    //init cache hal
+    cache_hal_init();
+    //init mmu
+    mmu_hal_init();
+    // update flash ID
+    bootloader_flash_update_id();
+    // Check and run XMC startup flow
+    esp_err_t ret = bootloader_flash_xmc_startup();
+    assert(ret == ESP_OK);
+
+    /* Alternative of bootloader_init_spi_flash */
+    // RAM app doesn't have headers in the flash. Make a default one for it.
+    esp_image_header_t WORD_ALIGNED_ATTR hdr = {
+        .spi_mode = ESP_IMAGE_SPI_MODE_DIO,
+        .spi_speed = ESP_IMAGE_SPI_SPEED_DIV_2,
+        .spi_size = ESP_IMAGE_FLASH_SIZE_2MB,
+    };
+
+    bootloader_configure_spi_pins(1);
+    bootloader_flash_set_spi_mode(&hdr);
+    bootloader_flash_clock_config(&hdr);
+    bootloader_flash_set_dummy_out();
+    bootloader_flash_cs_timing_config();
+
+    bootloader_spi_flash_resume();
+    bootloader_flash_unlock();
+
+    cache_hal_disable(CACHE_TYPE_ALL);
+    update_flash_config(&hdr);
+    cache_hal_enable(CACHE_TYPE_ALL);
+
+    //ensure the flash is write-protected
+    bootloader_enable_wp();
+}
+#endif //CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP

components/bootloader_support/bootloader_flash/src/bootloader_flash_config_esp32c6.c

@@ -219,3 +219,69 @@ esp_err_t bootloader_init_spi_flash(void)
     bootloader_enable_wp();
     return ESP_OK;
 }
+
+#if CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+static void bootloader_flash_set_spi_mode(const esp_image_header_t* pfhdr)
+{
+    esp_rom_spiflash_read_mode_t mode;
+    switch(pfhdr->spi_mode) {
+    case ESP_IMAGE_SPI_MODE_QIO:
+        mode = ESP_ROM_SPIFLASH_QIO_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_QOUT:
+        mode = ESP_ROM_SPIFLASH_QOUT_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_DIO:
+        mode = ESP_ROM_SPIFLASH_DIO_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_FAST_READ:
+        mode = ESP_ROM_SPIFLASH_FASTRD_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_SLOW_READ:
+        mode = ESP_ROM_SPIFLASH_SLOWRD_MODE;
+        break;
+    default:
+        mode = ESP_ROM_SPIFLASH_DIO_MODE;
+    }
+    esp_rom_spiflash_config_readmode(mode);
+}
+
+void bootloader_flash_hardware_init(void)
+{
+    esp_rom_spiflash_attach(0, false);
+
+    //init cache hal
+    cache_hal_init();
+    //init mmu
+    mmu_hal_init();
+    // update flash ID
+    bootloader_flash_update_id();
+    // Check and run XMC startup flow
+    esp_err_t ret = bootloader_flash_xmc_startup();
+    assert(ret == ESP_OK);
+
+    /* Alternative of bootloader_init_spi_flash */
+    // RAM app doesn't have headers in the flash. Make a default one for it.
+    esp_image_header_t WORD_ALIGNED_ATTR hdr = {
+        .spi_mode = ESP_IMAGE_SPI_MODE_DIO,
+        .spi_speed = ESP_IMAGE_SPI_SPEED_DIV_2,
+        .spi_size = ESP_IMAGE_FLASH_SIZE_2MB,
+    };
+
+    bootloader_configure_spi_pins(1);
+    bootloader_flash_set_spi_mode(&hdr);
+    bootloader_flash_clock_config(&hdr);
+    // TODO: set proper dummy output
+    bootloader_flash_cs_timing_config();
+
+    bootloader_spi_flash_resume();
+    bootloader_flash_unlock();
+
+    cache_hal_disable(CACHE_TYPE_ALL);
+    update_flash_config(&hdr);
+    cache_hal_enable(CACHE_TYPE_ALL);
+
+    //ensure the flash is write-protected
+    bootloader_enable_wp();
+}
+#endif //CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP

components/bootloader_support/bootloader_flash/src/bootloader_flash_config_esp32h2.c

@@ -221,3 +221,70 @@ esp_err_t bootloader_init_spi_flash(void)
     bootloader_enable_wp();
     return ESP_OK;
 }
+
+#if CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+static void bootloader_flash_set_spi_mode(const esp_image_header_t* pfhdr)
+{
+    esp_rom_spiflash_read_mode_t mode;
+    switch(pfhdr->spi_mode) {
+    case ESP_IMAGE_SPI_MODE_QIO:
+        mode = ESP_ROM_SPIFLASH_QIO_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_QOUT:
+        mode = ESP_ROM_SPIFLASH_QOUT_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_DIO:
+        mode = ESP_ROM_SPIFLASH_DIO_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_FAST_READ:
+        mode = ESP_ROM_SPIFLASH_FASTRD_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_SLOW_READ:
+        mode = ESP_ROM_SPIFLASH_SLOWRD_MODE;
+        break;
+    default:
+        mode = ESP_ROM_SPIFLASH_DIO_MODE;
+    }
+    esp_rom_spiflash_config_readmode(mode);
+}
+
+void bootloader_flash_hardware_init(void)
+{
+    esp_rom_spiflash_attach(0, false);
+
+    //init cache hal
+    cache_hal_init();
+    //init mmu
+    mmu_hal_init();
+    // update flash ID
+    bootloader_flash_update_id();
+    // Check and run XMC startup flow
+    esp_err_t ret = bootloader_flash_xmc_startup();
+    assert(ret == ESP_OK);
+
+    /* Alternative of bootloader_init_spi_flash */
+    // RAM app doesn't have headers in the flash. Make a default one for it.
+    esp_image_header_t WORD_ALIGNED_ATTR hdr = {
+        .spi_mode = ESP_IMAGE_SPI_MODE_DIO,
+        .spi_speed = ESP_IMAGE_SPI_SPEED_DIV_2,
+        .spi_size = ESP_IMAGE_FLASH_SIZE_2MB,
+    };
+
+    bootloader_configure_spi_pins(1);
+    bootloader_flash_set_spi_mode(&hdr);
+    bootloader_flash_clock_config(&hdr);
+    bootloader_flash_clock_init();
+    // TODO: set proper dummy output
+    bootloader_flash_cs_timing_config();
+
+    bootloader_spi_flash_resume();
+    bootloader_flash_unlock();
+
+    cache_hal_disable(CACHE_TYPE_ALL);
+    update_flash_config(&hdr);
+    cache_hal_enable(CACHE_TYPE_ALL);
+
+    //ensure the flash is write-protected
+    bootloader_enable_wp();
+}
+#endif //CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP

components/bootloader_support/bootloader_flash/src/bootloader_flash_config_esp32p4.c

@@ -207,3 +207,68 @@ esp_err_t bootloader_init_spi_flash(void)
     bootloader_enable_wp();
     return ESP_OK;
 }
+
+#if CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+static void bootloader_flash_set_spi_mode(const esp_image_header_t* pfhdr)
+{
+    esp_rom_spiflash_read_mode_t mode;
+    switch(pfhdr->spi_mode) {
+    case ESP_IMAGE_SPI_MODE_QIO:
+        mode = ESP_ROM_SPIFLASH_QIO_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_QOUT:
+        mode = ESP_ROM_SPIFLASH_QOUT_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_DIO:
+        mode = ESP_ROM_SPIFLASH_DIO_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_FAST_READ:
+        mode = ESP_ROM_SPIFLASH_FASTRD_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_SLOW_READ:
+        mode = ESP_ROM_SPIFLASH_SLOWRD_MODE;
+        break;
+    default:
+        mode = ESP_ROM_SPIFLASH_DIO_MODE;
+    }
+    esp_rom_spiflash_config_readmode(mode);
+}
+
+void bootloader_flash_hardware_init(void)
+{
+    esp_rom_spiflash_attach(0, false);
+
+    //init cache hal
+    cache_hal_init();
+    //reset mmu
+    mmu_hal_init();
+    // update flash ID
+    bootloader_flash_update_id();
+    // Check and run XMC startup flow
+    esp_err_t ret = bootloader_flash_xmc_startup();
+    assert(ret == ESP_OK);
+
+    /* Alternative of bootloader_init_spi_flash */
+    // RAM app doesn't have headers in the flash. Make a default one for it.
+    esp_image_header_t WORD_ALIGNED_ATTR hdr = {
+        .spi_mode = ESP_IMAGE_SPI_MODE_DIO,
+        .spi_speed = ESP_IMAGE_SPI_SPEED_DIV_2,
+        .spi_size = ESP_IMAGE_FLASH_SIZE_2MB,
+    };
+
+    bootloader_configure_spi_pins(1);
+    bootloader_flash_set_spi_mode(&hdr);
+    bootloader_flash_clock_config(&hdr);
+    bootloader_flash_cs_timing_config();
+
+    bootloader_spi_flash_resume();
+    bootloader_flash_unlock();
+
+    cache_hal_disable(CACHE_TYPE_ALL);
+    update_flash_config(&hdr);
+    cache_hal_enable(CACHE_TYPE_ALL);
+
+    //ensure the flash is write-protected
+    bootloader_enable_wp();
+}
+#endif //CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP

components/bootloader_support/bootloader_flash/src/bootloader_flash_config_esp32s2.c

@@ -81,6 +81,7 @@ void IRAM_ATTR bootloader_flash_set_dummy_out(void)
     REG_SET_BIT(SPI_MEM_CTRL_REG(1), SPI_MEM_FDUMMY_OUT | SPI_MEM_D_POL | SPI_MEM_Q_POL);
 }
 
+//deprecated
 void IRAM_ATTR bootloader_flash_dummy_config(const esp_image_header_t* pfhdr)
 {
     bootloader_configure_spi_pins(1);
@@ -247,7 +248,8 @@ static void print_flash_info(const esp_image_header_t *bootloader_hdr)
 
 static void IRAM_ATTR bootloader_init_flash_configure(void)
 {
-    bootloader_flash_dummy_config(&bootloader_image_hdr);
+    bootloader_configure_spi_pins(1);
+    bootloader_flash_set_dummy_out();
     bootloader_flash_cs_timing_config();
 }
 
@@ -274,3 +276,69 @@ esp_err_t bootloader_init_spi_flash(void)
     bootloader_enable_wp();
     return ESP_OK;
 }
+
+#if CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+static void bootloader_flash_set_spi_mode(const esp_image_header_t* pfhdr)
+{
+    esp_rom_spiflash_read_mode_t mode;
+    switch(pfhdr->spi_mode) {
+    case ESP_IMAGE_SPI_MODE_QIO:
+        mode = ESP_ROM_SPIFLASH_QIO_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_QOUT:
+        mode = ESP_ROM_SPIFLASH_QOUT_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_DIO:
+        mode = ESP_ROM_SPIFLASH_DIO_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_FAST_READ:
+        mode = ESP_ROM_SPIFLASH_FASTRD_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_SLOW_READ:
+        mode = ESP_ROM_SPIFLASH_SLOWRD_MODE;
+        break;
+    default:
+        mode = ESP_ROM_SPIFLASH_DIO_MODE;
+    }
+    esp_rom_spiflash_config_readmode(mode);
+}
+
+void bootloader_flash_hardware_init(void)
+{
+    esp_rom_spiflash_attach(esp_rom_efuse_get_flash_gpio_info(), false);
+
+    // init cache hal
+    cache_hal_init();
+    //init mmu
+    mmu_hal_init();
+    // Workaround: normal ROM bootloader exits with DROM0 cache unmasked, but 2nd bootloader exits with it masked.
+    REG_CLR_BIT(EXTMEM_PRO_ICACHE_CTRL1_REG, EXTMEM_PRO_ICACHE_MASK_DROM0);
+    // update flash ID
+    bootloader_flash_update_id();
+    // Check and run XMC startup flow
+    esp_err_t ret = bootloader_flash_xmc_startup();
+    assert(ret == ESP_OK);
+
+    /* Alternative of bootloader_init_spi_flash */
+    // RAM app doesn't have headers in the flash. Make a default one for it.
+    esp_image_header_t WORD_ALIGNED_ATTR hdr = {
+        .spi_mode = ESP_IMAGE_SPI_MODE_DIO,
+        .spi_speed = ESP_IMAGE_SPI_SPEED_DIV_2,
+        .spi_size = ESP_IMAGE_FLASH_SIZE_2MB,
+    };
+    bootloader_configure_spi_pins(1);
+    bootloader_flash_set_spi_mode(&hdr);
+    bootloader_flash_clock_config(&hdr);
+    bootloader_flash_set_dummy_out();
+    bootloader_flash_cs_timing_config();
+
+    bootloader_flash_unlock();
+
+    cache_hal_disable(CACHE_TYPE_ALL);
+    update_flash_config(&hdr);
+    cache_hal_enable(CACHE_TYPE_ALL);
+
+    //ensure the flash is write-protected
+    bootloader_enable_wp();
+}
+#endif //CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP

components/bootloader_support/bootloader_flash/src/bootloader_flash_config_esp32s3.c

@@ -87,6 +87,7 @@ void IRAM_ATTR bootloader_flash_set_dummy_out(void)
     REG_SET_BIT(SPI_MEM_CTRL_REG(1), SPI_MEM_FDUMMY_OUT | SPI_MEM_D_POL | SPI_MEM_Q_POL);
 }
 
+//deprecated
 void IRAM_ATTR bootloader_flash_dummy_config(const esp_image_header_t *pfhdr)
 {
     bootloader_configure_spi_pins(1);
@@ -254,7 +255,8 @@ static void print_flash_info(const esp_image_header_t *bootloader_hdr)
 
 static void IRAM_ATTR bootloader_init_flash_configure(void)
 {
-    bootloader_flash_dummy_config(&bootloader_image_hdr);
+    bootloader_configure_spi_pins(1);
+    bootloader_flash_set_dummy_out();
     bootloader_flash_cs_timing_config();
 }
 
@@ -297,3 +299,78 @@ esp_err_t bootloader_init_spi_flash(void)
     bootloader_enable_wp();
     return ESP_OK;
 }
+
+#if CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+static void bootloader_flash_set_spi_mode(const esp_image_header_t* pfhdr)
+{
+    esp_rom_spiflash_read_mode_t mode;
+    switch(pfhdr->spi_mode) {
+    case ESP_IMAGE_SPI_MODE_QIO:
+        mode = ESP_ROM_SPIFLASH_QIO_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_QOUT:
+        mode = ESP_ROM_SPIFLASH_QOUT_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_DIO:
+        mode = ESP_ROM_SPIFLASH_DIO_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_FAST_READ:
+        mode = ESP_ROM_SPIFLASH_FASTRD_MODE;
+        break;
+    case ESP_IMAGE_SPI_MODE_SLOW_READ:
+        mode = ESP_ROM_SPIFLASH_SLOWRD_MODE;
+        break;
+    default:
+        mode = ESP_ROM_SPIFLASH_DIO_MODE;
+    }
+    esp_rom_spiflash_config_readmode(mode);
+}
+
+void bootloader_flash_hardware_init(void)
+{
+    esp_rom_spiflash_attach(esp_rom_efuse_get_flash_gpio_info(), false);
+
+    //init cache hal
+    cache_hal_init();
+    //init mmu
+    mmu_hal_init();
+    // update flash ID
+    bootloader_flash_update_id();
+    // Check and run XMC startup flow
+    esp_err_t ret = bootloader_flash_xmc_startup();
+    assert(ret == ESP_OK);
+
+    /* Alternative of bootloader_init_spi_flash */
+    // RAM app doesn't have headers in the flash. Make a default one for it.
+    esp_image_header_t WORD_ALIGNED_ATTR hdr = {
+        .spi_mode = ESP_IMAGE_SPI_MODE_DIO,
+        .spi_speed = ESP_IMAGE_SPI_SPEED_DIV_2,
+        .spi_size = ESP_IMAGE_FLASH_SIZE_2MB,
+    };
+    bootloader_configure_spi_pins(1);
+    bootloader_flash_set_spi_mode(&hdr);
+    bootloader_flash_clock_config(&hdr);
+    bootloader_flash_set_dummy_out();
+    bootloader_flash_cs_timing_config();
+
+#if CONFIG_BOOTLOADER_FLASH_DC_AWARE
+    // Reset flash, clear volatile bits DC[0:1]. Make it work under default mode to boot.
+    bootloader_spi_flash_reset();
+#endif
+
+    bootloader_spi_flash_resume();
+    bootloader_flash_unlock();
+
+#if CONFIG_BOOTLOADER_CACHE_32BIT_ADDR_QUAD_FLASH || CONFIG_BOOTLOADER_CACHE_32BIT_ADDR_OCTAL_FLASH
+    bootloader_flash_32bits_address_map_enable(bootloader_flash_get_spi_mode());
+#endif
+
+    cache_hal_disable(CACHE_TYPE_ALL);
+    update_flash_config(&hdr);
+    cache_hal_enable(CACHE_TYPE_ALL);
+
+    //ensure the flash is write-protected
+    bootloader_enable_wp();
+
+}
+#endif //CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP

components/bootloader_support/src/bootloader_init.c

@@ -23,7 +23,9 @@
 
 static const char *TAG = "boot";
 
+#if !CONFIG_APP_BUILD_TYPE_RAM
 esp_image_header_t WORD_ALIGNED_ATTR bootloader_image_hdr;
+#endif
 
 void bootloader_clear_bss_section(void)
 {

components/bootloader_support/src/esp32/bootloader_esp32.c

@@ -39,7 +39,7 @@
 
 static const char *TAG = "boot.esp32";
 
-#if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#if !CONFIG_APP_BUILD_TYPE_RAM
 static void bootloader_reset_mmu(void)
 {
     /* completely reset MMU in case serial bootloader was running */
@@ -208,7 +208,7 @@ esp_err_t bootloader_init(void)
     /* print 2nd bootloader banner */
     bootloader_print_banner();
 
-#if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#if !CONFIG_APP_BUILD_TYPE_RAM
     // reset MMU
     bootloader_reset_mmu();
     // update flash ID
@@ -218,7 +218,6 @@ esp_err_t bootloader_init(void)
         ESP_LOGE(TAG, "failed when running XMC startup flow, reboot!");
         return ret;
     }
-#if !CONFIG_APP_BUILD_TYPE_RAM
     // read bootloader header
     if ((ret = bootloader_read_bootloader_header()) != ESP_OK) {
         return ret;
@@ -227,12 +226,11 @@ esp_err_t bootloader_init(void)
     if ((ret = bootloader_check_bootloader_validity()) != ESP_OK) {
         return ret;
     }
-#endif // #if !CONFIG_APP_BUILD_TYPE_RAM
     // initialize spi flash
     if ((ret = bootloader_init_spi_flash()) != ESP_OK) {
         return ret;
     }
-#endif  //#if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#endif // #if !CONFIG_APP_BUILD_TYPE_RAM
 
     // check whether a WDT reset happend
     bootloader_check_wdt_reset();

components/bootloader_support/src/esp32c2/bootloader_esp32c2.c

@@ -120,14 +120,13 @@ esp_err_t bootloader_init(void)
     /* print 2nd bootloader banner */
     bootloader_print_banner();
 
-#if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#if !CONFIG_APP_BUILD_TYPE_RAM
     //init cache hal
     cache_hal_init();
     //init mmu
     mmu_hal_init();
     // update flash ID
     bootloader_flash_update_id();
-#if !CONFIG_APP_BUILD_TYPE_RAM
     // read bootloader header
     if ((ret = bootloader_read_bootloader_header()) != ESP_OK) {
         return ret;
@@ -136,12 +135,11 @@ esp_err_t bootloader_init(void)
     if ((ret = bootloader_check_bootloader_validity()) != ESP_OK) {
         return ret;
     }
-#endif // !CONFIG_APP_BUILD_TYPE_RAM
     // initialize spi flash
     if ((ret = bootloader_init_spi_flash()) != ESP_OK) {
         return ret;
     }
-#endif  //#if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#endif // !CONFIG_APP_BUILD_TYPE_RAM
 
     // check whether a WDT reset happend
     bootloader_check_wdt_reset();

components/bootloader_support/src/esp32c3/bootloader_esp32c3.c

@@ -159,7 +159,7 @@ esp_err_t bootloader_init(void)
     /* print 2nd bootloader banner */
     bootloader_print_banner();
 
-#if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#if !CONFIG_APP_BUILD_TYPE_RAM
     //init cache hal
     cache_hal_init();
     //init mmu
@@ -171,7 +171,6 @@ esp_err_t bootloader_init(void)
         ESP_LOGE(TAG, "failed when running XMC startup flow, reboot!");
         return ret;
     }
-#if !CONFIG_APP_BUILD_TYPE_RAM
     // read bootloader header
     if ((ret = bootloader_read_bootloader_header()) != ESP_OK) {
         return ret;
@@ -180,12 +179,11 @@ esp_err_t bootloader_init(void)
     if ((ret = bootloader_check_bootloader_validity()) != ESP_OK) {
         return ret;
     }
-#endif  //#if !CONFIG_APP_BUILD_TYPE_RAM
     // initialize spi flash
     if ((ret = bootloader_init_spi_flash()) != ESP_OK) {
         return ret;
     }
-#endif // !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#endif  //#if !CONFIG_APP_BUILD_TYPE_RAM
 
     // check whether a WDT reset happend
     bootloader_check_wdt_reset();

components/bootloader_support/src/esp32c6/bootloader_esp32c6.c

@@ -143,7 +143,7 @@ esp_err_t bootloader_init(void)
     /* print 2nd bootloader banner */
     bootloader_print_banner();
 
-#if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#if !CONFIG_APP_BUILD_TYPE_RAM
     //init cache hal
     cache_hal_init();
     //init mmu
@@ -155,7 +155,6 @@ esp_err_t bootloader_init(void)
         ESP_LOGE(TAG, "failed when running XMC startup flow, reboot!");
         return ret;
     }
-#if !CONFIG_APP_BUILD_TYPE_RAM
     // read bootloader header
     if ((ret = bootloader_read_bootloader_header()) != ESP_OK) {
         return ret;
@@ -164,12 +163,11 @@ esp_err_t bootloader_init(void)
     if ((ret = bootloader_check_bootloader_validity()) != ESP_OK) {
         return ret;
     }
-#endif // !CONFIG_APP_BUILD_TYPE_RAM
     // initialize spi flash
     if ((ret = bootloader_init_spi_flash()) != ESP_OK) {
         return ret;
     }
-#endif // #if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#endif // !CONFIG_APP_BUILD_TYPE_RAM
 
     // check whether a WDT reset happend
     bootloader_check_wdt_reset();

components/bootloader_support/src/esp32h2/bootloader_esp32h2.c

@@ -132,7 +132,7 @@ esp_err_t bootloader_init(void)
     /* print 2nd bootloader banner */
     bootloader_print_banner();
 
-#if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#if !CONFIG_APP_BUILD_TYPE_RAM
     //init cache hal
     cache_hal_init();
     //init mmu
@@ -144,7 +144,6 @@ esp_err_t bootloader_init(void)
         ESP_LOGE(TAG, "failed when running XMC startup flow, reboot!");
         return ret;
     }
-#if !CONFIG_APP_BUILD_TYPE_RAM
     // read bootloader header
     if ((ret = bootloader_read_bootloader_header()) != ESP_OK) {
         return ret;
@@ -153,12 +152,11 @@ esp_err_t bootloader_init(void)
     if ((ret = bootloader_check_bootloader_validity()) != ESP_OK) {
         return ret;
     }
-#endif // !CONFIG_APP_BUILD_TYPE_RAM
     // initialize spi flash
     if ((ret = bootloader_init_spi_flash()) != ESP_OK) {
         return ret;
     }
-#endif  //#if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#endif // !CONFIG_APP_BUILD_TYPE_RAM
 
     // check whether a WDT reset happend
     bootloader_check_wdt_reset();

components/bootloader_support/src/esp32p4/bootloader_esp32p4.c

@@ -136,7 +136,7 @@ esp_err_t bootloader_init(void)
     /* print 2nd bootloader banner */
     bootloader_print_banner();
 
-#if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#if !CONFIG_APP_BUILD_TYPE_RAM
     //init cache hal
     cache_hal_init();
     //reset mmu
@@ -148,7 +148,6 @@ esp_err_t bootloader_init(void)
         ESP_LOGE(TAG, "failed when running XMC startup flow, reboot!");
         return ret;
     }
-#if !CONFIG_APP_BUILD_TYPE_RAM
     // read bootloader header
     if ((ret = bootloader_read_bootloader_header()) != ESP_OK) {
         return ret;
@@ -157,12 +156,11 @@ esp_err_t bootloader_init(void)
     if ((ret = bootloader_check_bootloader_validity()) != ESP_OK) {
         return ret;
     }
-#endif // !CONFIG_APP_BUILD_TYPE_RAM
     // initialize spi flash
     if ((ret = bootloader_init_spi_flash()) != ESP_OK) {
         return ret;
     }
-#endif // #if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#endif // !CONFIG_APP_BUILD_TYPE_RAM
 
     // check whether a WDT reset happend
     bootloader_check_wdt_reset();

components/bootloader_support/src/esp32s2/bootloader_esp32s2.c

@@ -139,7 +139,7 @@ esp_err_t bootloader_init(void)
     /* print 2nd bootloader banner */
     bootloader_print_banner();
 
-#if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#if !CONFIG_APP_BUILD_TYPE_RAM
     // init cache hal
     cache_hal_init();
     //init mmu
@@ -153,7 +153,6 @@ esp_err_t bootloader_init(void)
         ESP_LOGE(TAG, "failed when running XMC startup flow, reboot!");
         return ret;
     }
-#if !CONFIG_APP_BUILD_TYPE_RAM
     // read bootloader header
     if ((ret = bootloader_read_bootloader_header()) != ESP_OK) {
         return ret;
@@ -162,12 +161,11 @@ esp_err_t bootloader_init(void)
     if ((ret = bootloader_check_bootloader_validity()) != ESP_OK) {
         return ret;
     }
-#endif // !CONFIG_APP_BUILD_TYPE_RAM
     // initialize spi flash
     if ((ret = bootloader_init_spi_flash()) != ESP_OK) {
         return ret;
     }
-#endif // #if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#endif // !CONFIG_APP_BUILD_TYPE_RAM
 
     // check whether a WDT reset happend
     bootloader_check_wdt_reset();

components/bootloader_support/src/esp32s3/bootloader_esp32s3.c

@@ -178,7 +178,7 @@ esp_err_t bootloader_init(void)
     /* print 2nd bootloader banner */
     bootloader_print_banner();
 
-#if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#if !CONFIG_APP_BUILD_TYPE_RAM
     //init cache hal
     cache_hal_init();
     //init mmu
@@ -190,7 +190,6 @@ esp_err_t bootloader_init(void)
         ESP_LOGE(TAG, "failed when running XMC startup flow, reboot!");
         return ret;
     }
-#if !CONFIG_APP_BUILD_TYPE_RAM
     // read bootloader header
     if ((ret = bootloader_read_bootloader_header()) != ESP_OK) {
         return ret;
@@ -199,12 +198,11 @@ esp_err_t bootloader_init(void)
     if ((ret = bootloader_check_bootloader_validity()) != ESP_OK) {
         return ret;
     }
-#endif // !CONFIG_APP_BUILD_TYPE_RAM
     // initialize spi flash
     if ((ret = bootloader_init_spi_flash()) != ESP_OK) {
         return ret;
     }
-#endif // #if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+#endif // !CONFIG_APP_BUILD_TYPE_RAM
 
     // check whether a WDT reset happend
     bootloader_check_wdt_reset();

components/esp_system/port/cpu_start.c

@@ -101,6 +101,7 @@
 #if CONFIG_APP_BUILD_TYPE_RAM
 #include "esp_rom_spiflash.h"
 #include "bootloader_init.h"
+#include "esp_private/bootloader_flash_internal.h"
 #endif // CONFIG_APP_BUILD_TYPE_RAM
 
 //This dependency will be removed in the future
@@ -429,14 +430,10 @@ void IRAM_ATTR call_start_cpu0(void)
     // When the APP is loaded into ram for execution, some hardware initialization behaviors
     // in the bootloader are still necessary
 #if CONFIG_APP_BUILD_TYPE_RAM
+    bootloader_init();
 #if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
-#if SOC_SPI_MEM_SUPPORT_CONFIG_GPIO_BY_EFUSE
-    esp_rom_spiflash_attach(esp_rom_efuse_get_flash_gpio_info(), false);
-#else
-    esp_rom_spiflash_attach(0, false);
-#endif
+    bootloader_flash_hardware_init();
 #endif  //#if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
-    bootloader_init();
 #endif  //#if CONFIG_APP_BUILD_TYPE_RAM
 
 #ifndef CONFIG_BOOTLOADER_WDT_ENABLE
@@ -722,22 +719,19 @@ void IRAM_ATTR call_start_cpu0(void)
     }
 #endif //CONFIG_ESP_SYSTEM_MEMPROT_FEATURE && !CONFIG_ESP_SYSTEM_MEMPROT_TEST
 
+#if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+    // External devices (including SPI0/1, cache) should be initialized
+
+#if !CONFIG_APP_BUILD_TYPE_RAM
+    // Normal startup flow. We arrive here with the help of 1st, 2nd bootloader. There are valid headers (app/bootloader)
+
     // Read the application binary image header. This will also decrypt the header if the image is encrypted.
     __attribute__((unused)) esp_image_header_t fhdr = {0};
-#if CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
-    fhdr.spi_mode = ESP_IMAGE_SPI_MODE_DIO;
-    fhdr.spi_speed = ESP_IMAGE_SPI_SPEED_DIV_2;
-    fhdr.spi_size = ESP_IMAGE_FLASH_SIZE_4MB;
 
-    bootloader_flash_unlock();
-#else
     // This assumes that DROM is the first segment in the application binary, i.e. that we can read
     // the binary header through cache by accessing SOC_DROM_LOW address.
     hal_memcpy(&fhdr, (void *) SOC_DROM_LOW, sizeof(fhdr));
 
-#endif // CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
-
-#if !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
 #if CONFIG_IDF_TARGET_ESP32
 #if !CONFIG_SPIRAM_BOOT_INIT
     // If psram is uninitialized, we need to improve some flash configuration.
@@ -756,6 +750,10 @@ void IRAM_ATTR call_start_cpu0(void)
     }
     bootloader_flash_update_size(app_flash_size);
 #endif //CONFIG_SPI_FLASH_SIZE_OVERRIDE
+#else
+    // CONFIG_APP_BUILD_TYPE_RAM && !CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
+    bootloader_flash_unlock();
+#endif
 #endif //!CONFIG_APP_BUILD_TYPE_PURE_RAM_APP
 
 #if !CONFIG_ESP_SYSTEM_SINGLE_CORE_MODE