Remove usbboot, moved to raspberrypi/usbboot.git

usbboot/Readme.md

@@ -1,57 +1,6 @@
 # USB boot code
 
-This is the USB MSD boot code which should work on the Raspberry Pi model A and the Compute Module.
+Please note, this code has now moved to
 
-The BCM2835 device has a number of different modes for booting, the most obvious one is the SD card
-which looks for a file called bootcode.bin on the first FAT partition of the SD card to boot from.
+https://github.com/raspberrypi/usbboot.git
 
-The second method it can use is USB, the BCM2835 becomes a USB device which a standard PC (a Windows
-or Linux PC or even a Raspberry Pi) will enumerate.  The usbbootcode.bin is then squirted down the USB
-to the BCM2835.
-
-This is then executing the second stage boot process that normally looks for a file called config.txt
-and start.elf on the SD card and loads start.elf (or whatever version of start you require depending
-on the settings in config.txt).
-
-With usbbootcode.bin it re-enumerates as a device (but this time with a serial number of 1 to distinguish
-the second stage from the primary boot) and waits for a message packet from the host.  After
-The message packet it receives the data (the length is in the message packet), and it then checks the
-length of the downloaded information (should be an .elf file either msd.elf or buildroot.elf), if the
-length is greater than the size of the elf file, it assumes the rest of the data is a FAT16 image of a
-filesystem as created using the Raspberry Pi buildroot target raspberrypi_defconfig
-
-## Building
-
-Clone this on your Pi or an Ubuntu linux machine
-
-```
-$ git clone --depth=1 https://github.com/raspberrypi/tools
-$ cd tools/usbboot
-$ sudo apt-get install libusb-1.0-0-dev
-$ make
-$ sudo make install
-$ sudo rpiboot
-```
-
-Checkout the upstream buildroot from git
-
-```
-git clone git://git.buildroot.net/buildroot
-```
-
-Patch with Pi patches (requires raspberrypi/tools from above)
-
-```
-cd buildroot
-patch -p1 < ../tools/usbboot/buildroot.patch
-make raspberrypi_defconfig
-make
-```
-
-Note: you'll need superuser password to finish the build and create the image
-
-Running
-
-```
-sudo rpiboot -b buildroot/output/images/fatimage
-```