// Copyright 2015-2016 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 "esp_attr.h"
#include "esp_err.h"

#include "rom/ets_sys.h"
#include "rom/uart.h"
#include "rom/rtc.h"
#include "rom/cache.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 "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 "tcpip_adapter.h"

#include "esp_heap_alloc_caps.h"
#include "sdkconfig.h"
#include "esp_system.h"
#include "esp_spi_flash.h"
#include "nvs_flash.h"
#include "esp_event.h"
#include "esp_spi_flash.h"
#include "esp_ipc.h"
#include "esp_crosscore_int.h"
#include "esp_log.h"
#include "esp_vfs_dev.h"
#include "esp_newlib.h"
#include "esp_brownout.h"
#include "esp_int_wdt.h"
#include "esp_task_wdt.h"
#include "esp_phy_init.h"
#include "esp_cache_err_int.h"
#include "esp_coexist.h"
#include "esp_panic.h"
#include "esp_core_dump.h"
#include "trax.h"

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

void start_cpu0(void) __attribute__((weak, alias("start_cpu0_default")));
void start_cpu0_default(void) IRAM_ATTR;
#if !CONFIG_FREERTOS_UNICORE
static void IRAM_ATTR call_start_cpu1();
void start_cpu1(void) __attribute__((weak, alias("start_cpu1_default")));
void start_cpu1_default(void) IRAM_ATTR;
static bool app_cpu_started = false;
#endif //!CONFIG_FREERTOS_UNICORE

static void do_global_ctors(void);
static void main_task(void* args);
extern void app_main(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";

/*
 * 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()
{
#if CONFIG_FREERTOS_UNICORE
    RESET_REASON rst_reas[1];
#else
    RESET_REASON rst_reas[2];
#endif
    cpu_configure_region_protection();

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

    rst_reas[0] = rtc_get_reset_reason(0);
#if !CONFIG_FREERTOS_UNICORE
    rst_reas[1] = rtc_get_reset_reason(1);
#endif

    // from panic handler we can be reset by RWDT or TG0WDT
    if (rst_reas[0] == RTCWDT_SYS_RESET || rst_reas[0] == TG0WDT_SYS_RESET
#if !CONFIG_FREERTOS_UNICORE
        || rst_reas[1] == RTCWDT_SYS_RESET || rst_reas[1] == TG0WDT_SYS_RESET
#endif
        ) {
        // stop wdt in case of any
        esp_panic_wdt_stop();
    }

    //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[0] != DEEPSLEEP_RESET) {
        memset(&_rtc_bss_start, 0, (&_rtc_bss_end - &_rtc_bss_start) * sizeof(_rtc_bss_start));
    }

    ESP_EARLY_LOGI(TAG, "Pro cpu up.");

#if !CONFIG_FREERTOS_UNICORE
    ESP_EARLY_LOGI(TAG, "Starting app cpu, entry point is %p", call_start_cpu1);
    //Flush and enable icache for APP CPU
    Cache_Flush(1);
    Cache_Read_Enable(1);
    esp_cpu_unstall(1);
    //Enable clock gating and reset the app cpu.
    SET_PERI_REG_MASK(DPORT_APPCPU_CTRL_B_REG, DPORT_APPCPU_CLKGATE_EN);
    CLEAR_PERI_REG_MASK(DPORT_APPCPU_CTRL_C_REG, DPORT_APPCPU_RUNSTALL);
    SET_PERI_REG_MASK(DPORT_APPCPU_CTRL_A_REG, DPORT_APPCPU_RESETTING);
    CLEAR_PERI_REG_MASK(DPORT_APPCPU_CTRL_A_REG, DPORT_APPCPU_RESETTING);
    ets_set_appcpu_boot_addr((uint32_t)call_start_cpu1);

    while (!app_cpu_started) {
        ets_delay_us(100);
    }
#else
    ESP_EARLY_LOGI(TAG, "Single core mode");
    CLEAR_PERI_REG_MASK(DPORT_APPCPU_CTRL_B_REG, DPORT_APPCPU_CLKGATE_EN);
#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. */
    heap_alloc_caps_init();


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

#if !CONFIG_FREERTOS_UNICORE
void IRAM_ATTR call_start_cpu1()
{
    asm volatile (\
                  "wsr    %0, vecbase\n" \
                  ::"r"(&_init_start));

    cpu_configure_region_protection();

#if CONFIG_CONSOLE_UART_NONE
    ets_install_putc1(NULL);
    ets_install_putc2(NULL);
#else // CONFIG_CONSOLE_UART_NONE
    uartAttach();
    ets_install_uart_printf();
    uart_tx_switch(CONFIG_CONSOLE_UART_NUM);
#endif

    ESP_EARLY_LOGI(TAG, "App cpu up.");
    app_cpu_started = 1;
    start_cpu1();
}
#endif //!CONFIG_FREERTOS_UNICORE

void start_cpu0_default(void)
{
    esp_setup_syscall_table();
//Enable trace memory and immediately start trace.
#if CONFIG_MEMMAP_TRACEMEM
#if CONFIG_MEMMAP_TRACEMEM_TWOBANKS
    trax_enable(TRAX_ENA_PRO_APP);
#else
    trax_enable(TRAX_ENA_PRO);
#endif
    trax_start_trace(TRAX_DOWNCOUNT_WORDS);
#endif
    esp_set_cpu_freq();     // set CPU frequency configured in menuconfig
#ifndef CONFIG_CONSOLE_UART_NONE
    uart_div_modify(CONFIG_CONSOLE_UART_NUM, (rtc_clk_apb_freq_get() << 4) / CONFIG_CONSOLE_UART_BAUDRATE);
#endif
#if CONFIG_BROWNOUT_DET
    esp_brownout_init();
#endif
    rtc_gpio_force_hold_dis_all();
    esp_setup_time_syscalls();
    esp_vfs_dev_uart_register();
    esp_reent_init(_GLOBAL_REENT);
#ifndef CONFIG_CONSOLE_UART_NONE
    const char* default_uart_dev = "/dev/uart/" STRINGIFY(CONFIG_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
    do_global_ctors();
#if CONFIG_INT_WDT
    esp_int_wdt_init();
#endif
#if CONFIG_TASK_WDT
    esp_task_wdt_init();
#endif
    esp_cache_err_int_init();
    esp_crosscore_int_init();
    esp_ipc_init();
    spi_flash_init();
    /* init default OS-aware flash access critical section */
    spi_flash_guard_set(&g_flash_guard_default_ops);

#if CONFIG_ESP32_ENABLE_COREDUMP
    esp_core_dump_init();
#endif

    xTaskCreatePinnedToCore(&main_task, "main",
            ESP_TASK_MAIN_STACK, NULL,
            ESP_TASK_MAIN_PRIO, NULL, 0);
    ESP_LOGI(TAG, "Starting scheduler on PRO CPU.");
    vTaskStartScheduler();
}

#if !CONFIG_FREERTOS_UNICORE
void start_cpu1_default(void)
{
#if CONFIG_MEMMAP_TRACEMEM_TWOBANKS
    trax_start_trace(TRAX_DOWNCOUNT_WORDS);
#endif
    // Wait for FreeRTOS initialization to finish on PRO CPU
    while (port_xSchedulerRunning[0] == 0) {
        ;
    }
    //Take care putting stuff here: if asked, FreeRTOS will happily tell you the scheduler
    //has started, but it isn't active *on this CPU* yet.
    esp_cache_err_int_init();
    esp_crosscore_int_init();

    ESP_EARLY_LOGI(TAG, "Starting scheduler on APP CPU.");
    xPortStartScheduler();
}
#endif //!CONFIG_FREERTOS_UNICORE

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

static void main_task(void* args)
{
    // Now that the application is about to start, disable boot watchdogs
    REG_CLR_BIT(TIMG_WDTCONFIG0_REG(0), TIMG_WDT_FLASHBOOT_MOD_EN_S);
    REG_CLR_BIT(RTC_CNTL_WDTCONFIG0_REG, RTC_CNTL_WDT_FLASHBOOT_MOD_EN);
    //Enable allocation in region where the startup stacks were located.
    heap_alloc_enable_nonos_stack_tag();
    app_main();
    vTaskDelete(NULL);
}