Unexpected additional sectors erased using Flash Download Tool

[YimingLi]

Hi Espressif,

We found that the Flash Download Tool might erase additional more sectors than expected during downloading. That is, if we download an image file, whose size may cover sectors less than sector N (a section size is 4096), and the download log also shows that burning to an address inside section N, however after downloading the image file sucessfully using espressif flash download tool, the next section N+1 is found to have been erased as well !

Example 1: try to download an image file which extends to address 0x6C004 (0x6C004 is just an example, something like these which covers only a few bytes of a start of sector), and there are some useful data stored since 0x6D000(start of the next sector 0f 4096). After downloading the image file, the useful data from 0x6D000 is found to have been erased to be all 0xFF.

Example 2: try to download an image file small in size (less than the size of a sector, 4096) to the last sector of the SPI flash(e.g. download blank.bin or esp_init_data_default.bin which is only 128Bytes to an address of 0x0FF000 on a flash of 1MBytes, or 0x1FF000 on flash of 2MBytes, or 0x3FF000 on a Flash of 4Mbytes) . After downloading successfully, the original boot at address 0 is found to have been erased and the module will not boot up successfully. Then you would have to re-download the boot at address 0.

Test Tools: previous FLASH_DOWNLOAD_TOOLS_v1.2_150512, and lastest FLASH_DOWNLOAD_TOOLS_V3.4.9.2 (downloaded from http://www.espressif.com/en/support/dow ... ther-tools)

Test modules: ESP-01, ESP-12 serials and many other ESP8266 modules

UART baudrate used during test: 115200 and 1152000 (both tell successful downloading, but with unexpected additional sectors erased)

Reproduction: always 100%.

Please help confirm or clarify.

Thanks!

Yiming

[pratik]

The issue has been forwarded to the developers of the Flash Download Tool. I will let you know if I get any new info on this. Thanks for writing about it!

[ESP_Faye]

Hi,

It is a known issue in the ESP8266 Flash Download Tool. But we decided to leave it at that since there are already so many developers using the tool. It may cause some incompatible issues for other users if we fix it.

So sorry for the inconvenience. And thanks for your interest in ESP8266!