usb pen bypass

Isn't it possible to use a usb pen drive, to flash the firmware on psp's or to at least modify the psp so it reads a lower psp firmware version this will help all the 2.01 and 2.5 people out their. USB doesn't have any security and can bypass the cpu, so surely it can be used to have direct access to the firmware, and allow the firmware to be modified ? :eek:
All you need to do is write a virus and put it on the memory stick then plug it in the psp with a convertor cable ? why has this not yet been done ? the usb can't surely just allow you to access the memory card in the psp, or whats the point, the usb has a direct feed into the firmware, so you can use it for psp hardware add on's. can this not be tested ?

No. Search. USB on the PSP is not "on-the-go". Doesn't matter if you have a convertor cable or NOT, you'll still need something else to "see" the memory stick on the PSP in order to manipulate files.