A recovery boot (aka TE USB FX2 firmware recovery) is a multi-step boot operation:
Cypress firmware update tools and OpenFutNet can read and write the EEPROM:
for example using CyControl (Cypress USB Control Center);
See also Cypress USB Control Center recovery boot and Cypress USB Console recovery boot videos for further information about the procedures to follow.
Second step (bootloader Vend_ax in RAM) is hidden
The 2nd stage loader firmware is loaded automatically without the explicit intervention of the user. At this time, it is only possible with Windows OS.
In an implicit two-step recovery boot, the user should (the necessary device driver is assumed already installed (
))give the command to load the desired good firmware into FX2 microcontroller's external EEPROM using CyControl, CyConsole, OpenFutNet (Windows OS, all SW tools using CyAPI.lib or CyUSB.dll) ;
The CyConsole's "Lg EEPROM" button, CyControl's "64KB EEPROM" button and OpenFutNet's "Program USB: write IIC EEPROM" button call the loadEEPROM() function. This function is used to program 64-Kbyte EEPROMs. When the button (CyConsole's Lg EEPROM button, CyControl's EEPROM button or OpenFutNet's IIC button) is clicked, the user is prompted to select a (.iic) file to load into the EEPROM. This button first downloads the Vend_Ax.bix file, then sends the 0xA9 vendor request to program the EEPROM.
The CyConsole/CyControl/OpenFutNet program will load
(hidden/implicit 1) an intermediate good firmware supporting EEPROM programming (normally the 2nd stage bootloader Vend_Ax.hex ) in RAM;