Boot header affects use of USB

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by cyrilfougeray on Mon Aug 12 03:16:11 MST 2013
I'm currently porting U-Boot on the LPC4350-DB1 and I have some issue with my USB CDC driver.

I've got a working U-boot which boot from Flash (no header attached to the image). Program starts in flash and copies some sections into local SRAM (0x10000000), then jumps in it. This firmware is totally working with USB CDC and I get the console connecting to ttyACM0.

But I want a DFU version which must contain a header. I modified the link script and now my program starts at 0x00000000 (Boot code copies the firmware in shadow area). U-Boot is working, but not my USB CDC driver, I got this error with 'dmesg -c' command :

[ 6859.173222] usb 3-3: new high-speed USB device number 76 using xhci_hcd
[ 6859.189522] usb 3-3: device descriptor read/8, error -61
[ 6859.309338] usb 3-3: device descriptor read/8, error -61
[ 6859.412937] hub 3-0:1.0: unable to enumerate USB device on port 3

I think boot code causes the issue because U-Boot works in both version.

If you have any idea about how the boot code can affect the use of USB ?

Thanks !