Appendix-Configuring Issi & Mxic Flash Qio Mode - Espressif Systems ESP8266 SDK Getting Started Manual

!
A. Appendix—Configuring ISSI &
⚠ Notice:
Choose DIO or DOUT mode when downloading, otherwise errors may occur. There is no need to modify
binaries in DIO or DOUT mode.
When using QIO mode of ISSI flash or MXIC flash, users need to modify the first two bytes
in blank.bin, as shown in Table A-1. During initialization, ESP8266 will automatically check
the first two bytes and switch to QIO mode to read ISSI_FLASH or MXIC_FLASH. The
structure of blank.bin is shown below:
strcut boot_hdr{
char user_bin:2; //low_bit
char boot_status:1;
char to_qio:1;
char reverse:4;
char version:5; //low bit
char test_pass_flag:1;
char test_start_flag:1;
char enhance_boot_flag:1;
}
Without secondary boot loader
With secondary boot loader
Espressif
MXIC Flash QIO Mode
Table A-1. blank.bin Configuration
Option
Modify to_qio to 0.
Modify use_bin to 0 and to_qio to 0, as well. Modify version
according to the current boot version.
Example:
If users use the secondary boot_v1.5.bin, please modify the first two
bytes FF FF to F4 E5.
30 33 !
Description
/!
Appendix A
2017.05