After a failed attempt to write a bootloader using a wrong image in Kindle Fire HD 7“ from a friend, was totally dead, black screen, no sign of life.
As I went through this with my Galaxy Nexus who also has an OMAP4 CPU, I decided to follow the same steps to retrieve it using the usbboot. For this it was necessary to remove the battery and solder a small wire connecting pin
USB Boot to GND to be recognized as
omap44xx usb device in my linux PC.
The pin in question is below:
1 2 3
After that, just download and compile the usbboot through the sources that can be found here.