[SOLVED]How does SDK1.4 determine flash size?

[tve]

I am trying to build firmware that will work with any flash size from 512KB to 4MB and one of the key items is how does the SDK determine the flash size for the purpose of placing the "system param" flash area?
I know that the flash size is stored in two places: in the header of the bootloader (at flash address 0) and in the header of the boot-mode 2 user1.bin/user2.bin files (this is put there by gen_appbin.py). From my tests it seems that the header of the bootloader is what the SDK uses, at least that's what system_get_flash_size_map returns. Is the flash size in the header of the user1.bin/user2.bin used for anything?

[ESP_Faye]

Hi,

Yes, the system_get_flash_size_map can get the flash size & map.

Thanks for your interest in ESP8266 !

[tve]

Mhh, that wasn't my question, I know that.
My question is where does the SDK get the flash map from ? Is it from the header in the boot sector?

[ESP_Faye]

Hi,

Start from Flash 0x00000

Code: Select all

struct flash_hdr {
   char magic;
   char blocks;
   char spi_mode;
   char spi_speed: 4;  // low
   char spi_size: 4;
   unsigned int entry_addr;
};


The "spi_size" is corresponding to the enum below:

Code: Select all

enum flash_size_map {
    FLASH_SIZE_4M_MAP_256_256 = 0,
    FLASH_SIZE_2M,
    FLASH_SIZE_8M_MAP_512_512,
    FLASH_SIZE_16M_MAP_512_512,
    FLASH_SIZE_32M_MAP_512_512,
    FLASH_SIZE_16M_MAP_1024_1024,
    FLASH_SIZE_32M_MAP_1024_1024
};


Thanks for your interest in ESP8266 !

[tito]

Mhh, that wasn't my question, I know that.
My question is where does the SDK get the flash map from ? Is it from the header in the boot sector?

I believe by reading SPI FLASH ID - spi_flash_get_id().

[tve]

Thanks much!