帮我写一段s32k144 bootloader 程序

好的，以下是一个简单的 s32k144 bootloader 程序的示例代码，仅供参考：

#include "s32k144.h"

#define FLASH_BASE_ADDR 0x00000000
#define FLASH_SECTOR_SIZE 0x1000 // 4KB sector size
#define BOOTLOADER_SIZE 0x4000 // 16KB bootloader size

typedef void (*app_entry_t)(void);

int main(void)
{
    app_entry_t app_entry;

    // Check if the bootloader should enter the application
    if (*((volatile uint32_t*)FLASH_BASE_ADDR) != 0xFFFFFFFF)
    {
        // Jump to application
        app_entry = (app_entry_t)(*((volatile uint32_t*)(FLASH_BASE_ADDR + 4)));
        app_entry();
    }

    // Initialize peripherals
    // ...

    // Erase bootloader sector
    FTFE_FSTAT = FTFE_FSTAT_ACCERR_MASK | FTFE_FSTAT_FPVIOL_MASK; // Clear errors
    FTFE_FCCOB0 = 0x0A; // Erase sector command
    FTFE_FCCOB1 = FLASH_BASE_ADDR >> 16; // Sector address (MSB)
    FTFE_FCCOB2 = FLASH_BASE_ADDR >> 8; // Sector address
    FTFE_FCCOB3 = FLASH_BASE_ADDR; // Sector address (LSB)
    FTFE_FSTAT = FTFE_FSTAT_CCIF_MASK; // Launch command

    // Wait for command to complete
    while (!(FTFE_FSTAT & FTFE_FSTAT_CCIF_MASK));

    // Program application entry address
    FTFE_FSTAT = FTFE_FSTAT_ACCERR_MASK | FTFE_FSTAT_FPVIOL_MASK; // Clear errors
    FTFE_FCCOB0 = 0x07; // Program phrase command
    FTFE_FCCOB1 = (FLASH_BASE_ADDR + 4) >> 16; // Address (MSB)
    FTFE_FCCOB2 = (FLASH_BASE_ADDR + 4) >> 8; // Address
    FTFE_FCCOB3 = FLASH_BASE_ADDR + 4; // Address (LSB)
    FTFE_FCCOB4 = ((uint32_t)app_entry) >> 24; // Data (MSB)
    FTFE_FCCOB5 = ((uint32_t)app_entry) >> 16; // Data
    FTFE_FCCOB6 = ((uint32_t)app_entry) >> 8; // Data
    FTFE_FCCOB7 = (uint32_t)app_entry; // Data (LSB)
    FTFE_FSTAT = FTFE_FSTAT_CCIF_MASK; // Launch command

    // Wait for command to complete
    while (!(FTFE_FSTAT & FTFE_FSTAT_CCIF_MASK));

    // Jump to application
    app_entry();

    // Should never get here
    return 0;
}

这个 bootloader 程序会首先检查 flash 的第一个字是否为 0xFFFFFFFF，如果不是，就表示有一个应用程序需要被执行，于是会跳转到应用程序的入口地址。如果是，则表示没有应用程序需要被执行，于是会先进行 flash 擦除，然后将应用程序的入口地址写入 flash。最后再跳转到应用程序的入口地址。这个示例程序仅供参考，实际应用中可能需要进行更多的错误处理和安全措施。