Storage of permanent variables for powerloss

Question

Hi, i'm implementing a GUI with LizardBoard that runs Embedded Wizard.

LIZARD Board is based on STM32F469.

The goal is to store data permanently, so if a powerloss occours or the user want to set some parameters to be stored, the data is permanently saved.

In the Build Enviroment for Lizard Board available. in the website, the flash script file for data sections defines the Flash and QuadSPI pheripherals (code follows):

/* Specify the memory areas */
MEMORY
{
  FLASH (rx)  : ORIGIN = 0x8000000,  LENGTH = 2048K
  RAM (xrw)   : ORIGIN = 0x20000000, LENGTH = 320K
  CCMRAM (rw) : ORIGIN = 0x10000000, LENGTH = 64K
  QSPI (xr)   : ORIGIN = 0x90000000, LENGTH = 64M
}

/* Define output sections */
SECTIONS
{
  /* The startup code goes first into FLASH */
  .isr_vector :
  {
    . = ALIGN(4);
    KEEP(*(.isr_vector)) /* Startup code */
    . = ALIGN(4);
  } >FLASH

  /* The Embedded Wizard resource rodata goes into external FLASH */
  .SectionEwResource :
  {
    . = ALIGN(4);
    *(.SectionEwResource)
    . = ALIGN(4);
  } >QSPI

 

I see that the embedded wizard Read Only data is defined.

 

My question is, can i use Embedded Wizard to write/read those variables? or do i have to pass through some additional code?

 

Thanks

Answer 1

Hello,

generally there are many options within an embedded system to store data permanently, for example serial Flash memory, EEPROM, SDCard, USB storage, network, ....

From Embedded Wizard side there are no predefined interfaces to manage persistent data - you can create your own device interface and read/write the data for your GUI application within the storage device of your choice. Maybe you are accessing your flash driver directly or maybe you have some kind of file system.

The flash region that you mentioned in your question is the flash region of the linker script that is used by the linker to locate constant data of your application. If you want to write this area during runtime from your application you need your own flash driver to erase and program the flash sections.

Best regards,

Manfred. 

Comments

Thanks Manfred