Documentation: Add binary extraction documentation

Added documentation on how to extract binaries from a ROM image,
including:

- Using ifdtool to extract binaries.
- Using cbfstool to extract binaries.
- Changing menuconfig to use the extracted binaries.

Change-Id: Ia31b01afc66789f95c7d21a0d41b532bc19a6430
Signed-off-by: Logan Carlson <logancarlson@google.com>
Reviewed-on: https://review.coreboot.org/20753
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>

Documentation/Binary Extraction.md

@@ -0,0 +1,68 @@
+# Intel IFD Binary Extraction Tutorial
+
+## Part 1: Extracting Binaries
+
+To begin extracting the binaries, first create a directory labeled "binaries"
+in the coreboot directory (i.e. /path/to/coreboot/binaries/).
+
+Now, execute the following commands to extract the binaries from a ROM image.
+**Note:** Make sure you are in the root coreboot directory.
+
+    cd /path/to/coreboot/util/ifdtool
+    ./ifdtool COREBOOT_IMAGE
+    ./ifdtool -d COREBOOT_IMAGE
+    ./ifdtool -x COREBOOT_IMAGE
+
+In the above steps, COREBOOT_IMAGE is the name of the ROM image to extract the
+binaries from, including the file path (ex. /build/coreboot.rom).
+
+Copy the extracted .bin files to the binaries directory you created previously.
+**Note:** You may want to rename your various .bin files to more clearly
+indicate what they are and their purpose.
+
+To extract the mrc.bin, move to the /coreboot/build directory and run the
+following command:
+
+    cd /path/to/coreboot/build/
+    ./cbfstool COREBOOT_IMAGE extract -n mrc.bin -f /path/to/destination/filename
+
+where COREBOOT_IMAGE is the filepath to the ROM image (same image as above),
+/path/to/destination is the filepath to the destination directory and filename
+is the output filename. An example command is given below:
+
+    ./cbfstool coreboot.rom extract -n mrc.bin -f /path/to/coreboot/binaries/mrc.bin
+
+## Part 2: Using extract_blobs.sh
+
+To simplify some of the steps above, there is a script in the
+/path/to/coreboot/util/chromeos/ directory called extract_blobs.sh what will
+extract the flashdescriptor.bin and intel_me.bin files.
+
+To run this script, switch to the /path/to/coreboot/util/chromeos/ directory
+and execute the script providing a coreboot image as an argument.
+
+    cd /path/to/coreboot/util/chromeos/
+    ./extract_blobs.sh COREBOOT_IMAGE
+
+Executing those commands will result in two binary blobs to appear in the
+/path/to/coreboot/util/chromeos/ directory under the names
+'flashdescriptor.bin' and 'me.bin'.
+
+## Part 3: Changing the coreboot configuration settings
+
+To begin using the binaries extracted above, enable the use of binary
+repositories in the menuconfig. From the main coreboot directory, run
+'make menuconfig'. Select "General Setup", then select "Allow use of
+binary-only repository", then exit to the main menu.
+
+To configure the ROM image for a specific board, select "Mainboard". Select
+"Mainboard vendor" and scroll to the correct vendor. Then select "Mainboard
+model" and select the name of the board model. Exit back to the main menu.
+
+To add the binaries you extracted, select "Chipset". Scroll and select "Add a
+System Agent Binary" and set the filepath to your mrc.bin file's filepath.
+Scroll and select "Add Intel descriptor.bin file" and type the filepath for
+your descriptor.bin file. Scroll down and select "Add Intel ME/TXE firmware
+file" and type the filepath for your ME file. Exit to the main menu.
+
+Select "Exit", and select "Yes" when prompted to save your configuration.