#include "main.h"

#define APP_ADDRESS             0x08040000UL
#define APP_FLASH_END           0x08100000UL
#define SRAM_START              0x20000000UL
#define SRAM_END                0x20020000UL

/* Kept for legacy source files that remain in the Keil project. */
UART_HandleTypeDef huart1;
UART_HandleTypeDef huart2;
DMA_HandleTypeDef hdma_usart1_rx;
DMA_HandleTypeDef hdma_usart2_rx;

typedef void (*app_entry_t)(void);

void MX_DMA_DeInit(void)
{
}

void MX_USART_DeInit(void)
{
}

static void boot_jump_to_app(void)
{
    uint32_t app_stack = *(volatile uint32_t *)APP_ADDRESS;
    uint32_t app_reset = *(volatile uint32_t *)(APP_ADDRESS + 4U);
    app_entry_t app_entry;

    /* Do not branch through an erased or invalid application vector table. */
    if ((app_stack < SRAM_START) || (app_stack >= SRAM_END) ||
        (app_reset < APP_ADDRESS) || (app_reset >= APP_FLASH_END)) {
        while (1) {
        }
    }

    __disable_irq();

    SysTick->CTRL = 0;
    SysTick->LOAD = 0;
    SysTick->VAL = 0;

    for (uint32_t i = 0; i < 8U; i++) {
        NVIC->ICER[i] = 0xFFFFFFFFUL;
        NVIC->ICPR[i] = 0xFFFFFFFFUL;
    }

    HAL_DeInit();
    SCB->VTOR = APP_ADDRESS;
    __set_MSP(app_stack);
    __set_CONTROL(0);
    __DSB();
    __ISB();

    app_entry = (app_entry_t)app_reset;
    app_entry();

    while (1) {
    }
}

int main(void)
{
    HAL_Init();
    boot_jump_to_app();

    while (1) {
    }
}