From 1b608a1c0757529c54b701961f97fd17195f6149 Mon Sep 17 00:00:00 2001
From: KonstantinKondrashov <konstantin@espressif.com>
Date: Fri, 31 Mar 2023 19:46:27 +0800
Subject: [PATCH] esp_system: Do not rely on bootloader cache settings, do
 cache settings unconditionally at startup app

It makes multicore app runnable by unicore bootloader

Closes https://github.com/espressif/esp-idf/issues/10714
---
 .../bootloader_support/src/bootloader_init.c  |  8 ++++
 components/esp_system/port/cpu_start.c        | 45 +++++++++++++++++++
 components/hal/esp32/include/hal/cache_ll.h   | 32 +++++++++++++
 components/hal/esp32s3/include/hal/cache_ll.h | 31 +++++++++++++
 4 files changed, 116 insertions(+)

diff --git a/components/bootloader_support/src/bootloader_init.c b/components/bootloader_support/src/bootloader_init.c
index 932cac265c..3fc18415d7 100644
--- a/components/bootloader_support/src/bootloader_init.c
+++ b/components/bootloader_support/src/bootloader_init.c
@@ -94,4 +94,12 @@ void bootloader_print_banner(void)
 {
     ESP_LOGI(TAG, "ESP-IDF %s 2nd stage bootloader", IDF_VER);
     ESP_LOGI(TAG, "compile time " __TIME__);
+
+#if CONFIG_FREERTOS_UNICORE
+#if (SOC_CPU_CORES_NUM > 1)
+    ESP_EARLY_LOGW(TAG, "Unicore bootloader");
+#endif
+#else
+    ESP_EARLY_LOGI(TAG, "Multicore bootloader");
+#endif
 }
diff --git a/components/esp_system/port/cpu_start.c b/components/esp_system/port/cpu_start.c
index 913bfb6144..f2c18f7237 100644
--- a/components/esp_system/port/cpu_start.c
+++ b/components/esp_system/port/cpu_start.c
@@ -70,6 +70,10 @@
 #include "hal/wdt_hal.h"
 #include "soc/rtc.h"
 #include "soc/efuse_reg.h"
+#if (SOC_CPU_CORES_NUM > 1)
+#include "hal/cache_ll.h"
+#endif
+#include "hal/efuse_ll.h"
 #include "soc/periph_defs.h"
 #include "soc/cpu.h"
 #include "soc/rtc.h"
@@ -244,6 +248,39 @@ static void start_other_core(void)
         esp_rom_delay_us(100);
     }
 }
+
+// This function is needed to make the multicore app runnable on a unicore bootloader (built with FREERTOS UNICORE).
+// It does some cache settings for other CPUs.
+void IRAM_ATTR do_multicore_settings(void)
+{
+    // We intentionally do not check the cache settings before changing them,
+    // because it helps to get the application to run on older bootloaders.
+#ifdef CONFIG_IDF_TARGET_ESP32
+    if (!efuse_ll_get_disable_app_cpu()) {
+        Cache_Read_Disable(1);
+        Cache_Flush(1);
+        DPORT_REG_SET_BIT(DPORT_APP_CACHE_CTRL1_REG, DPORT_APP_CACHE_MMU_IA_CLR);
+        DPORT_REG_CLR_BIT(DPORT_APP_CACHE_CTRL1_REG, DPORT_APP_CACHE_MMU_IA_CLR);
+        // We do not enable cache for CPU1 now because it will be done later in start_other_core().
+    }
+#endif
+
+    cache_bus_mask_t cache_bus_mask_core0 = cache_ll_l1_get_enabled_bus(0);
+#ifndef CONFIG_IDF_TARGET_ESP32
+    // 1. disable the cache before changing its settings.
+    Cache_Disable_ICache();
+    Cache_Disable_DCache();
+#endif
+    for (unsigned core = 1; core < SOC_CPU_CORES_NUM; core++) {
+        // 2. change cache settings. All cores must have the same settings.
+        cache_ll_l1_enable_bus(core, cache_bus_mask_core0);
+    }
+#ifndef CONFIG_IDF_TARGET_ESP32
+    // 3. enable the cache after changing its settings.
+    Cache_Enable_ICache(0);
+    Cache_Enable_DCache(0);
+#endif
+}
 #endif // !CONFIG_ESP_SYSTEM_SINGLE_CORE_MODE
 
 /*
@@ -312,6 +349,14 @@ void IRAM_ATTR call_start_cpu0(void)
         memset(&_rtc_bss_start, 0, (&_rtc_bss_end - &_rtc_bss_start) * sizeof(_rtc_bss_start));
     }
 
+#if CONFIG_ESP_SYSTEM_SINGLE_CORE_MODE
+    ESP_EARLY_LOGI(TAG, "Unicore app");
+#else
+    ESP_EARLY_LOGI(TAG, "Multicore app");
+    // It helps to fix missed cache settings for other cores. It happens when bootloader is unicore.
+    do_multicore_settings();
+#endif
+
 #if CONFIG_IDF_TARGET_ESP32S2
     /* Configure the mode of instruction cache : cache size, cache associated ways, cache line size. */
     extern void esp_config_instruction_cache_mode(void);
diff --git a/components/hal/esp32/include/hal/cache_ll.h b/components/hal/esp32/include/hal/cache_ll.h
index 7157eff9c5..ec7dd87d94 100644
--- a/components/hal/esp32/include/hal/cache_ll.h
+++ b/components/hal/esp32/include/hal/cache_ll.h
@@ -55,6 +55,38 @@ static inline void cache_ll_l1_enable_bus(uint32_t cache_id, cache_bus_mask_t ma
     }
 }
 
+/**
+ * Returns enabled buses for a given core
+ *
+ * @param cache_id    cache ID (when l1 cache is per core)
+ *
+ * @return State of enabled buses
+ */
+__attribute__((always_inline))
+static inline cache_bus_mask_t cache_ll_l1_get_enabled_bus(uint32_t cache_id)
+{
+    cache_bus_mask_t mask = 0;
+    HAL_ASSERT(cache_id == 0 || cache_id == 1);
+    if (cache_id == 0) {
+        uint32_t bus_mask= DPORT_REG_READ(DPORT_PRO_CACHE_CTRL1_REG);
+        mask |= (!(bus_mask & DPORT_PRO_CACHE_MASK_IRAM0)) ? CACHE_BUS_IBUS0 : 0;
+        mask |= (!(bus_mask & DPORT_PRO_CACHE_MASK_IRAM1)) ? CACHE_BUS_IBUS1 : 0;
+        mask |= (!(bus_mask & DPORT_PRO_CACHE_MASK_IROM0)) ? CACHE_BUS_IBUS2 : 0;
+
+        mask |= (!(bus_mask & DPORT_PRO_CACHE_MASK_DROM0)) ? CACHE_BUS_DBUS0 : 0;
+        mask |= (!(bus_mask & DPORT_PRO_CACHE_MASK_DRAM1)) ? CACHE_BUS_DBUS1 : 0;
+    } else {
+        uint32_t bus_mask= DPORT_REG_READ(DPORT_APP_CACHE_CTRL1_REG);
+        mask |= (!(bus_mask & DPORT_APP_CACHE_MASK_IRAM0)) ? CACHE_BUS_IBUS0 : 0;
+        mask |= (!(bus_mask & DPORT_APP_CACHE_MASK_IRAM1)) ? CACHE_BUS_IBUS1 : 0;
+        mask |= (!(bus_mask & DPORT_APP_CACHE_MASK_IROM0)) ? CACHE_BUS_IBUS2 : 0;
+
+        mask |= (!(bus_mask & DPORT_APP_CACHE_MASK_DROM0)) ? CACHE_BUS_DBUS0 : 0;
+        mask |= (!(bus_mask & DPORT_APP_CACHE_MASK_DRAM1)) ? CACHE_BUS_DBUS1 : 0;
+    }
+    return mask;
+}
+
 /**
  * Disable the Cache Buses
  *
diff --git a/components/hal/esp32s3/include/hal/cache_ll.h b/components/hal/esp32s3/include/hal/cache_ll.h
index c4de594de1..58125d0a3f 100644
--- a/components/hal/esp32s3/include/hal/cache_ll.h
+++ b/components/hal/esp32s3/include/hal/cache_ll.h
@@ -49,6 +49,37 @@ static inline void cache_ll_l1_enable_bus(uint32_t cache_id, cache_bus_mask_t ma
     REG_CLR_BIT(EXTMEM_DCACHE_CTRL1_REG, dbus_mask);
 }
 
+/**
+ * Returns enabled buses for a given core
+ *
+ * @param cache_id    cache ID (when l1 cache is per core)
+ *
+ * @return State of enabled buses
+ */
+__attribute__((always_inline))
+static inline cache_bus_mask_t cache_ll_l1_get_enabled_bus(uint32_t cache_id)
+{
+    cache_bus_mask_t mask = 0;
+    HAL_ASSERT(cache_id == 0 || cache_id == 1);
+    //On esp32s3, only `CACHE_BUS_IBUS0` and `CACHE_BUS_DBUS0` are supported. Use `cache_ll_l1_get_bus()` to get your bus first
+
+    uint32_t ibus_mask = REG_READ(EXTMEM_ICACHE_CTRL1_REG);
+    if (cache_id == 0) {
+        mask |= (!(ibus_mask & EXTMEM_ICACHE_SHUT_CORE0_BUS)) ? CACHE_BUS_IBUS0 : 0;
+    } else {
+        mask |= (!(ibus_mask & EXTMEM_ICACHE_SHUT_CORE1_BUS)) ? CACHE_BUS_IBUS0 : 0;
+    }
+
+    uint32_t dbus_mask = REG_READ(EXTMEM_DCACHE_CTRL1_REG);
+    if (cache_id == 1) {
+        mask |= (!(dbus_mask & EXTMEM_DCACHE_SHUT_CORE0_BUS)) ? CACHE_BUS_DBUS0 : 0;
+    } else {
+        mask |= (!(dbus_mask & EXTMEM_DCACHE_SHUT_CORE1_BUS)) ? CACHE_BUS_DBUS0 : 0;
+    }
+
+    return mask;
+}
+
 /**
  * Disable the Cache Buses
  *