How to write the settings to EEFLASH(0x0807E000) in advance rather than calling FLASH read-write functions

[NIIYD]

HI teacher:
I am crazy when i cant resolve the problem

After successfully building the open-source project GrblHAL with Keil5, the debugging phase did not begin.

It was discovered that some of the grblHAL settings parameters were written in advance to the FLASH of GD32
at 0x0807E000, rather than calling FLASH read-write functions. How was this achieved?

flash.c
#define _EEPROM_Emul_Sector 63U /*暂定NVS在第63页上，0x0807E000-0x0807FFFF*/ #define _EEPROM_Emul_Start ((uint32_t)0x0807E000U)
nvsbuffer.c
`
bool nvs_buffer_init (void)
{
hal.nvs.size = ((hal.nvs.size - 1) | 0x03) + 1; // Ensure NVS area ends on a word boundary

if(nvsbuffer) 
  {
    //*******************************************************************************************
    //save pointers to physical storage handler functions
    //把hal中处理nvs函数的指针保存到physical_nvs里，physical_nvs是hal.nvs的副本 
    memcpy(&physical_nvs, &hal.nvs, sizeof(nvs_io_t));                                                                                              
                                                                                                       
    // Copy physical storage content to RAM when available
    // 在可用时,将物理存储内容复制到RAM
    if(physical_nvs.type == NVS_Flash)                       //如果hal.nvs存储在EEFLASH里

        physical_nvs.memcpy_from_flash(nvsbuffer);   //Reading Settings data from EEFLASH to nvsbuffer (in RAM), 
                                                                                 //EEFLASH (0x0807E000) actually  have these data, which is generated 
                                                                                 //during construction and downloaded to the chip instead of calling FLASH
                                                                                // read-write functions. How can this be achieved? 
    else if(physical_nvs.type != NVS_None)                            
        physical_nvs.memcpy_from_nvs(nvsbuffer, 0, GRBL_NVS_SIZE + hal.nvs.driver_area.size, false);

    // Switch hal to use RAM version of non-volatile storage data
    hal.nvs.type = NVS_Emulated;
    hal.nvs.get_byte = ram_get_byte;
    hal.nvs.put_byte = ram_put_byte;
    hal.nvs.memcpy_to_nvs = memcpy_to_ram;
    hal.nvs.memcpy_from_nvs = memcpy_from_ram;
    hal.nvs.memcpy_from_flash = NULL;
    hal.nvs.memcpy_to_flash = NULL;

    // If no physical storage available or if NVS import fails copy default settings to RAM
    // and write out to physical storage when available.
    if(physical_nvs.type == NVS_None || ram_get_byte(0) != SETTINGS_VERSION) //-----------------
      {
        settings_restore(settings_all);  
        if(physical_nvs.type == NVS_Flash)
            physical_nvs.memcpy_to_flash(nvsbuffer);
        
        else if(physical_nvs.memcpy_to_nvs)
            physical_nvs.memcpy_to_nvs(0, nvsbuffer, GRBL_NVS_SIZE + hal.nvs.driver_area.size, false);
        
        if(physical_nvs.type != NVS_None)
            grbl.report.status_message(Status_SettingReadFail);
      }
   } 
 else
    protocol_enqueue_foreground_task(report_warning, "Not enough heap for NVS buffer!");

// Clear settings dirty flags
memset(&settings_dirty, 0, sizeof(settings_dirty_t));

return nvsbuffer != NULL;

}
`

[terjeio]

Reading/writing to flash is done via code pointed to by hal.nvs function pointers set up in the driver, e.g. like this. The code called by this driver is found here. The core code buffers the data and to achive this it saves and replaces the function pointers so that read/writes are initially done from/to the buffer. Later changes are written to flash by calling the saved function pointers.