After reviewing the iMX6SL reference manual + datasheets and the PW3 PCB photos provided by @bdm310 within
this thread, I was able to establish that the boot control pins needed to enter USB Serial Download mode are broken out to test pads on the back of the PW3 PCB at these locations:
- BOOT_MODE_0 - TM401
- BOOT_MODE_1 - TM402
Both of the pads listed above are also present on the KT2 and I was able to enter USB Serial Download on this device by pulling TM401 up to 3.3v. The KT2 appears with the product name "SE Blank MEGREZ" and VID:PID 15a2:0063, and a u-boot image can be loaded using imx_usb_loader with this config:
Code:
KindleTouch2
#hid/bulk,[old_header,]max packet size, dcd_addr, {ram start, ram size}(repeat valid ram areas)
hid,1024,0x910000,0x70000000,256M,0xF8000000,128K