How to add USB DFU for TM4C1294 project?

Hello David,

The Flash boot loader is going to look at a specified location for the application image. So why it should be different from the position as expected by the boot loader?

Regards
Amit

No, I didn't mean that.

My test was just to show DFU is smart enough to protect itself and the users don't need to worry about " If there is a Flash based boot loader then 0x0 cannot be used as it will try to overwrite the Flash boot loader.", as long as I don't define ENABLE_BL_UPDATE

Hello David,

Yes, that is correct,

Regards
Amit

Hi Amit,

The USB DFU you helped me to create works fine so far.

Recently, I have a request to invoke USB DFU from within the program instead of during power up

According to e2e.ti.com/.../249914, invoking SVCALL is the way to go, so I added the following codes to my project:

#define CallBootLoader() (*((void (*)(void))(*(unsigned long *)0x2c)))()
...

switch (command){
case USB_DFU:
USBDevDisconnect(USB0_BASE);
CallBootLoader();
...

When this command is called, the original USB device is indeed removed from device manager, but I don't see the DFU USB device show up in the list

Anything I may be missing?

Thanks for your time!

Hello David,

When the call is made by the application, can you check if the System Clock and USB Divider is configured correctly?

Also an additional step is to disable the interrupts in the NVIC by writing 0xFFFFFFFF to all the NVIC_DISx registers which does not seem to be the case here.

Since I was still using USB communication before calling USBDevDisconnect(USB0_BASE) and CallBootLoader(), I assume the USB was still configured properly?

If not, what should it be?

Thanks!

Thanks, disabling SysTick solved the problem!