Yesterday I'm thinking about making a actual USB stick board to be the actual iCEBlaster. Right now the iCEBlaster with VFS is virtually works on any STM32 that have USB MSC. Then I recalled that there's the 20 pins STM32F042F6P6. And it might work with the original code. But need to do some code shrinking to fit the 32kBytes flash and 6kBytes SRAM. Code is done but untested. I also designed the PCB for iCEBlaster too. 

Anyway, I'm now sure that the tricky delay still work or not. But in order to make the code fit in 32k. I need to optimize the code (I selected the optimize for debug). Hope that it won't mess up while(cnt--); delay.