// Copyright 2015-2018 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include <stdint.h>
#include <string.h>
#include "sdkconfig.h"
#include "esp_attr.h"
#include "esp_err.h"

#include "esp32s2beta/rom/ets_sys.h"
#include "esp32s2beta/rom/uart.h"
#include "esp32s2beta/rom/rtc.h"
#include "esp32s2beta/rom/cache.h"
#include "esp32s2beta/dport_access.h"
#include "esp32s2beta/brownout.h"
#include "esp32s2beta/cache_err_int.h"
#include "esp32s2beta/spiram.h"

#include "soc/cpu.h"
#include "soc/rtc.h"
#include "soc/dport_reg.h"
#include "soc/io_mux_reg.h"
#include "soc/rtc_cntl_reg.h"
#include "soc/timer_group_reg.h"
#include "soc/periph_defs.h"
#include "soc/rtc_wdt.h"
#include "driver/rtc_io.h"

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/semphr.h"
#include "freertos/queue.h"
#include "freertos/portmacro.h"

#include "esp_heap_caps_init.h"
#include "esp_system.h"
#include "esp_spi_flash.h"
#include "esp_flash_internal.h"
#include "nvs_flash.h"
#include "esp_event.h"
#include "esp_spi_flash.h"
#include "esp_ipc.h"
#include "esp_private/crosscore_int.h"
#include "esp_log.h"
#include "esp_vfs_dev.h"
#include "esp_newlib.h"
#include "esp_int_wdt.h"
#include "esp_task.h"
#include "esp_task_wdt.h"
#include "esp_phy_init.h"
#include "esp_coexist_internal.h"
#include "esp_debug_helpers.h"
#include "esp_core_dump.h"
#include "esp_app_trace.h"
#include "esp_private/dbg_stubs.h"
#include "esp_clk_internal.h"
#include "esp_timer.h"
#include "esp_pm.h"
#include "esp_private/pm_impl.h"
#include "trax.h"
#include "esp_efuse.h"

#define STRINGIFY(s) STRINGIFY2(s)
#define STRINGIFY2(s) #s

void start_cpu0(void) __attribute__((weak, alias("start_cpu0_default"))) __attribute__((noreturn));
void start_cpu0_default(void) IRAM_ATTR __attribute__((noreturn));

static void do_global_ctors(void);
static void main_task(void *args);
extern void app_main(void);
extern esp_err_t esp_pthread_init(void);

extern int _bss_start;
extern int _bss_end;
extern int _rtc_bss_start;
extern int _rtc_bss_end;
extern int _init_start;
extern void (*__init_array_start)(void);
extern void (*__init_array_end)(void);
extern volatile int port_xSchedulerRunning[2];

static const char *TAG = "cpu_start";

struct object {
    long placeholder[ 10 ];
};
void __register_frame_info (const void *begin, struct object *ob);
extern char __eh_frame[];

//If CONFIG_SPIRAM_IGNORE_NOTFOUND is set and external RAM is not found or errors out on testing, this is set to false.
static bool s_spiram_okay = true;

/*
 * We arrive here after the bootloader finished loading the program from flash. The hardware is mostly uninitialized,
 * and the app CPU is in reset. We do have a stack, so we can do the initialization in C.
 */

void IRAM_ATTR call_start_cpu0(void)
{
    RESET_REASON rst_reas;

    cpu_configure_region_protection();

    //Move exception vectors to IRAM
    asm volatile (\
                  "wsr    %0, vecbase\n" \
                  ::"r"(&_init_start));

    rst_reas = rtc_get_reset_reason(0);

    // from panic handler we can be reset by RWDT or TG0WDT
    if (rst_reas == RTCWDT_SYS_RESET || rst_reas == TG0WDT_SYS_RESET) {
#ifndef CONFIG_BOOTLOADER_WDT_ENABLE
        rtc_wdt_disable();
#endif
    }

    //Clear BSS. Please do not attempt to do any complex stuff (like early logging) before this.
    memset(&_bss_start, 0, (&_bss_end - &_bss_start) * sizeof(_bss_start));

    /* Unless waking from deep sleep (implying RTC memory is intact), clear RTC bss */
    if (rst_reas != DEEPSLEEP_RESET) {
        memset(&_rtc_bss_start, 0, (&_rtc_bss_end - &_rtc_bss_start) * sizeof(_rtc_bss_start));
    }

    /* Configure the mode of instruction cache : cache size, cache associated ways, cache line size. */
    extern void esp_config_instruction_cache_mode(void);
    esp_config_instruction_cache_mode();

    /* copy MMU table from ICache to DCache, so we can use DCache to access rodata later. */
#if CONFIG_ESP32S2_RODATA_USE_DATA_CACHE
    MMU_Drom0_I2D_Copy();
#endif

    /* If we need use SPIRAM, we should use data cache, or if we want to access rodata, we also should use data cache.
       Configure the mode of data : cache size, cache associated ways, cache line size.
       Enable data cache, so if we don't use SPIRAM, it just works. */
#if CONFIG_SPIRAM_BOOT_INIT
    extern void esp_config_data_cache_mode(void);
    esp_config_data_cache_mode();
    Cache_Enable_DCache(0);
#endif

    /* In SPIRAM code, we will reconfigure data cache, as well as instruction cache, so that we can:
       1. make data buses works with SPIRAM
       2. make instruction and rodata work with SPIRAM, still through instruction cache */
#if CONFIG_SPIRAM_BOOT_INIT
    esp_spiram_init_cache();
    if (esp_spiram_init() != ESP_OK) {
#if CONFIG_SPIRAM_IGNORE_NOTFOUND
        ESP_EARLY_LOGI(TAG, "Failed to init external RAM; continuing without it.");
        s_spiram_okay = false;
#else
        ESP_EARLY_LOGE(TAG, "Failed to init external RAM!");
        abort();
#endif
    }
#endif

    ESP_EARLY_LOGI(TAG, "Pro cpu up.");
    ESP_EARLY_LOGI(TAG, "Single core mode");

#if CONFIG_SPIRAM_MEMTEST
    if (s_spiram_okay) {
        bool ext_ram_ok = esp_spiram_test();
        if (!ext_ram_ok) {
            ESP_EARLY_LOGE(TAG, "External RAM failed memory test!");
            abort();
        }
    }
#endif

#if CONFIG_SPIRAM_FETCH_INSTRUCTIONS
    extern void esp_spiram_enable_instruction_access(void);
    esp_spiram_enable_instruction_access();
#endif
#if CONFIG_SPIRAM_RODATA
    extern void esp_spiram_enable_rodata_access(void);
    esp_spiram_enable_rodata_access();
#endif

#if CONFIG_ESP32S2_INSTRUCTION_CACHE_WRAP || CONFIG_ESP32S2_DATA_CACHE_WRAP
    uint32_t icache_wrap_enable = 0, dcache_wrap_enable = 0;
#if CONFIG_ESP32S2_INSTRUCTION_CACHE_WRAP
    icache_wrap_enable = 1;
#endif
#if CONFIG_ESP32S2_DATA_CACHE_WRAP
    dcache_wrap_enable = 1;
#endif
    extern void esp_enable_cache_wrap(uint32_t icache_wrap_enable, uint32_t dcache_wrap_enable);
    esp_enable_cache_wrap(icache_wrap_enable, dcache_wrap_enable);
#endif

    /* Initialize heap allocator. WARNING: This *needs* to happen *after* the app cpu has booted.
       If the heap allocator is initialized first, it will put free memory linked list items into
       memory also used by the ROM. Starting the app cpu will let its ROM initialize that memory,
       corrupting those linked lists. Initializing the allocator *after* the app cpu has booted
       works around this problem.
       With SPI RAM enabled, there's a second reason: half of the SPI RAM will be managed by the
       app CPU, and when that is not up yet, the memory will be inaccessible and heap_caps_init may
       fail initializing it properly. */
    heap_caps_init();

    ESP_EARLY_LOGI(TAG, "Pro cpu start user code");
    start_cpu0();
}

static void intr_matrix_clear(void)
{
    //Clear all the interrupt matrix register
    for (int i = ETS_WIFI_MAC_INTR_SOURCE; i < ETS_MAX_INTR_SOURCE; i++) {
        intr_matrix_set(0, i, ETS_INVALID_INUM);
    }
}

void start_cpu0_default(void)
{
    esp_err_t err;
    esp_setup_syscall_table();

    if (s_spiram_okay) {
#if CONFIG_SPIRAM_BOOT_INIT && (CONFIG_SPIRAM_USE_CAPS_ALLOC || CONFIG_SPIRAM_USE_MALLOC)
        esp_err_t r = esp_spiram_add_to_heapalloc();
        if (r != ESP_OK) {
            ESP_EARLY_LOGE(TAG, "External RAM could not be added to heap!");
            abort();
        }
#if CONFIG_SPIRAM_MALLOC_RESERVE_INTERNAL
        r = esp_spiram_reserve_dma_pool(CONFIG_SPIRAM_MALLOC_RESERVE_INTERNAL);
        if (r != ESP_OK) {
            ESP_EARLY_LOGE(TAG, "Could not reserve internal/DMA pool!");
            abort();
        }
#endif
#if CONFIG_SPIRAM_USE_MALLOC
        heap_caps_malloc_extmem_enable(CONFIG_SPIRAM_MALLOC_ALWAYSINTERNAL);
#endif
#endif
    }

//Enable trace memory and immediately start trace.
#if CONFIG_ESP32S2_TRAX
    trax_enable(TRAX_ENA_PRO);
    trax_start_trace(TRAX_DOWNCOUNT_WORDS);
#endif
#if !CONFIG_IDF_ENV_FPGA // ToDo: remove it once we get a real chip
    esp_clk_init();
    esp_perip_clk_init();
#else
    ets_update_cpu_frequency(CONFIG_ESP32S2_DEFAULT_CPU_FREQ_MHZ);
#endif
    intr_matrix_clear();

#ifndef CONFIG_ESP_CONSOLE_UART_NONE
#ifdef CONFIG_PM_ENABLE
    const int uart_clk_freq = REF_CLK_FREQ;
    /* When DFS is enabled, use REFTICK as UART clock source */
    CLEAR_PERI_REG_MASK(UART_CONF0_REG(CONFIG_ESP_CONSOLE_UART_NUM), UART_TICK_REF_ALWAYS_ON);
#else
    const int uart_clk_freq = APB_CLK_FREQ;
#endif // CONFIG_PM_DFS_ENABLE
    uart_div_modify(CONFIG_ESP_CONSOLE_UART_NUM, (uart_clk_freq << 4) / CONFIG_ESP_CONSOLE_UART_BAUDRATE);
#endif // CONFIG_ESP_CONSOLE_UART_NONE

#if CONFIG_ESP32S2_BROWNOUT_DET
    esp_brownout_init();
#endif
#if CONFIG_ESP32S2_DISABLE_BASIC_ROM_CONSOLE
    esp_efuse_disable_basic_rom_console();
#endif
    rtc_gpio_force_hold_dis_all();
    esp_vfs_dev_uart_register();
    esp_reent_init(_GLOBAL_REENT);
#ifndef CONFIG_ESP_CONSOLE_UART_NONE
    const char *default_uart_dev = "/dev/uart/" STRINGIFY(CONFIG_ESP_CONSOLE_UART_NUM);
    _GLOBAL_REENT->_stdin  = fopen(default_uart_dev, "r");
    _GLOBAL_REENT->_stdout = fopen(default_uart_dev, "w");
    _GLOBAL_REENT->_stderr = fopen(default_uart_dev, "w");
#else
    _GLOBAL_REENT->_stdin  = (FILE *) &__sf_fake_stdin;
    _GLOBAL_REENT->_stdout = (FILE *) &__sf_fake_stdout;
    _GLOBAL_REENT->_stderr = (FILE *) &__sf_fake_stderr;
#endif
    esp_timer_init();
    esp_set_time_from_rtc();
#if CONFIG_APPTRACE_ENABLE
    err = esp_apptrace_init();
    assert(err == ESP_OK && "Failed to init apptrace module on PRO CPU!");
#endif
#if CONFIG_SYSVIEW_ENABLE
    SEGGER_SYSVIEW_Conf();
#endif
#if CONFIG_ESP32S2_DEBUG_STUBS_ENABLE
    esp_dbg_stubs_init();
#endif
    err = esp_pthread_init();
    assert(err == ESP_OK && "Failed to init pthread module!");

    do_global_ctors();
#if CONFIG_ESP_INT_WDT
    esp_int_wdt_init();
    //Initialize the interrupt watch dog
    esp_int_wdt_cpu_init();
#endif
    esp_cache_err_int_init();
    esp_crosscore_int_init();
    spi_flash_init();
    /* init default OS-aware flash access critical section */
    spi_flash_guard_set(&g_flash_guard_default_ops);

    esp_flash_app_init();
    esp_err_t flash_ret = esp_flash_init_default_chip();
    assert(flash_ret == ESP_OK);

#ifdef CONFIG_PM_ENABLE
    esp_pm_impl_init();
#ifdef CONFIG_PM_DFS_INIT_AUTO
    rtc_cpu_freq_t max_freq;
    rtc_clk_cpu_freq_from_mhz(CONFIG_ESP32S2_DEFAULT_CPU_FREQ_MHZ, &max_freq);
    esp_pm_config_esp32_t cfg = {
        .max_cpu_freq = max_freq,
        .min_cpu_freq = RTC_CPU_FREQ_XTAL
    };
    esp_pm_configure(&cfg);
#endif //CONFIG_PM_DFS_INIT_AUTO
#endif //CONFIG_PM_ENABLE

#if CONFIG_ESP32_ENABLE_COREDUMP
    esp_core_dump_init();
#endif

    portBASE_TYPE res = xTaskCreatePinnedToCore(&main_task, "main",
                        ESP_TASK_MAIN_STACK, NULL,
                        ESP_TASK_MAIN_PRIO, NULL, 0);
    assert(res == pdTRUE);
    ESP_LOGI(TAG, "Starting scheduler on PRO CPU.");
    vTaskStartScheduler();
    abort(); /* Only get to here if not enough free heap to start scheduler */
}

#ifdef CONFIG_COMPILER_CXX_EXCEPTIONS
size_t __cxx_eh_arena_size_get(void)
{
    return CONFIG_COMPILER_CXX_EXCEPTIONS_EMG_POOL_SIZE;
}
#endif

static void do_global_ctors(void)
{
#ifdef CONFIG_COMPILER_CXX_EXCEPTIONS
    static struct object ob;
    __register_frame_info( __eh_frame, &ob );
#endif

    void (**p)(void);
    for (p = &__init_array_end - 1; p >= &__init_array_start; --p) {
        (*p)();
    }
}

static void main_task(void *args)
{
    //Enable allocation in region where the startup stacks were located.
    heap_caps_enable_nonos_stack_heaps();

    //Initialize task wdt if configured to do so
#ifdef CONFIG_ESP_TASK_WDT_PANIC
    ESP_ERROR_CHECK(esp_task_wdt_init(CONFIG_ESP_TASK_WDT_TIMEOUT_S, true));
#elif CONFIG_ESP_TASK_WDT
    ESP_ERROR_CHECK(esp_task_wdt_init(CONFIG_ESP_TASK_WDT_TIMEOUT_S, false));
#endif

    //Add IDLE 0 to task wdt
#ifdef CONFIG_ESP_TASK_WDT_CHECK_IDLE_TASK_CPU0
    TaskHandle_t idle_0 = xTaskGetIdleTaskHandleForCPU(0);
    if (idle_0 != NULL) {
        ESP_ERROR_CHECK(esp_task_wdt_add(idle_0));
    }
#endif

    // Now that the application is about to start, disable boot watchdog
#ifndef CONFIG_BOOTLOADER_WDT_DISABLE_IN_USER_CODE
    rtc_wdt_disable();
#endif

#ifdef CONFIG_BOOTLOADER_EFUSE_SECURE_VERSION_EMULATE
    const esp_partition_t *efuse_partition = esp_partition_find_first(ESP_PARTITION_TYPE_DATA, ESP_PARTITION_SUBTYPE_DATA_EFUSE_EM, NULL);
    if (efuse_partition) {
        esp_efuse_init(efuse_partition->address, efuse_partition->size);
    }
#endif

    app_main();
    vTaskDelete(NULL);
}