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--- devices:pi_flashrom [2018/12/14 14:07] – Sean Rhone
+++ devices:pi_flashrom [2018/12/14 14:09] (current) – [Coreboot] Sean Rhone
@@ Line 1: / Line 1: @@
+====== Information ======
+  * Using a Raspberry Pi to read and write to a 8-pin chip using flashrom
+====== Requirements ======
+  * Raspberry Pi ((https://www.raspberrypi.org/products/)) ((I've only tested the **2 Model B** and **3 Model B**))
+  * Raspbian ((https://www.raspbian.org/))
+  * flashrom ((in Raspbian repos or can be compiled))
+  * Pomona SOIC Clip Model 5250, 8 Pin ((https://www.pomonaelectronics.com/products/test-clips/soic-clip-8-pin)) ((any similar 8-pin SOIC clip should work))
+  * Male to Female Breadboard wires ((to connect the SOIC clip to the Pi's GPIO pins))
+  * TODO: Separate notes for 16-pin if needed
+====== Pi ======
+===== Configuration =====
+  * Install Raspbian
+  * Update Raspbian packages
+  * Enable SPI ((TODO: Is this needed? May be enabled out-the-box))
+===== Pins =====
+==== Physical ====
+  * The physical numbering and order of the pins on a Pi
+  * ''[  ]'' represents a pin
+  * ''O'' represents a mounting hole
+  * The ASCII art assumes the I/O ports are on the right-side and the pins are at the top
+  * 1, 2, 3, 4, 37, 38, 39, and 40 are unused and only provided for reference as to pin order
+<code>
+ -----------------------------------------------------------------------------------------------------   ----------
+| [ 2] [ 4] [  ] [  ] [  ] [  ] [  ] [  ] [  ] [  ] [  ] [24] [  ] [  ] [  ] [  ] [  ] [  ] [38] [40] | |          |
+O [ 1] [ 3] [  ] [  ] [  ] [  ] [  ] [  ] [17] [19] [21] [23] [25] [  ] [  ] [  ] [  ] [  ] [37] [39] O |   USB    |
+|                                                                                                     | |          |
+VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV (chips and other stuff below) VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV</code>
+==== GPIO ====
+  * https://www.raspberrypi.org/documentation/usage/gpio/images/gpio-numbers-pi2.png
+  * The GPIO numbering and order of the pins on a Pi
+  * ''[  ]'' represents a pin
+  * ''O'' represents a mounting hole
+  * The ASCII art assumes the I/O ports are on the right-side and the pins are at the top
+  * 5v, far-left 3.3v, 21, and far-right GND are unused and only provided for reference
+<code>
+ -----------------------------------------------------------------------------------------------------------   ----------
+| [5v  ] [  ] [  ] [  ] [  ] [  ] [  ] [  ] [    ] [  ] [  ] [ 8] [   ] [  ] [  ] [  ] [  ] [  ] [  ] [21 ] | |          |
+O [3.3V] [  ] [  ] [  ] [  ] [  ] [  ] [  ] [3.3V] [10] [ 9] [11] [GND] [  ] [  ] [  ] [  ] [  ] [  ] [GND] O |   USB    |
+|                                                                                                           | |          |
+VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV (chips and other stuff below) VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV</code>
+====== W25Q64FV ======
+===== Information =====
+  * [[https://www.pjrc.com/store/w25q64fv.pdf|Spec Sheet]]
+  * This chip is commonly used as a BIOS chip on computer motherboards
+  * Detects as a ''W25Q64.V'' in ''flashrom''
+  * :!: On a XPS 13, the chip identifies as a ''W25Q256.V'' and follows the same pin layout and instructions ((TODO: separate notes?))
+===== Pins =====
+  * Numbering of the pins on the chip according to the spec sheet
+<code>
+      --------
+[1]__|O       |__[8]
+[2]__|  Chip  |__[7]
+[3]__|        |__[6]
+[4]__|        |__[5]
+      --------</code>
+===== Pin Descriptions =====
+  * What the pins on the chip do
+<code>
+        --------
+[/CS]__|O       |__[VCC]
+ [DO]__|  Chip  |__[/HOLD]
+[/WP]__|        |__[CLK]
+[GND]__|        |__[DI]
+        --------</code>
+===== SOIC Clip to Pi Pins =====
+  * The ''\ \'' represents the springs on the clip
+  * This image assumes the clip's pins are on the left and right side in the same orientation as the above pictures ((the circle notch on the chip is top-left))
+  * The numbers here refer to the [[#physical|physical pins]] on the Pi and their numbering, **not** GPIO pin numbers
+<code>
+[24]      [17]
+[21] \ \  [  ]
+[  ]  \ \ [23]
+[25]      [19]</code>
+====== flashrom ======
+===== Install =====
+==== Pre-compiled ====
+  * As of 2018/04/27, this supports a ''W25Q64FV''
+  * As of 2018/12/09, this does not support a ''W25Q256.V'' ((this requires a Git build))
+  sudo apt install 'flashrom'
+==== Git Compile ====
+=== Dependencies ===
+****
+  sudo apt install libpci-dev libftdi-dev libusb-1.0-0-dev git-core build-essential
+=== Get Source ===
+****
+  rm -Rf ~/'flashrom' && git clone -b 'master' 'https://github.com/flashrom/flashrom.git' ~/'flashrom' --depth '1'
+=== Build ===
+****
+  cd ~/'flashrom' && make --jobs='4' && sync
+===== Test Chip Read =====
+  * Assumes the SOIC clip is connected to the Pi correctly and that SPI is enabled
+  * All 3 md5sums **need** to match to ensure consistent read/write to the chip
+  * ''spispeed=8000'' is necessary for reading from a ''W25Q64FV'' chip
+  sudo flashrom --programmer 'linux_spi':'dev=/dev/spidev0.0,spispeed=8000' --read ~/'test1.bin' && sudo flashrom --programmer 'linux_spi':'dev=/dev/spidev0.0,spispeed=8000' --read ~/'test2.bin' && sudo flashrom --programmer 'linux_spi':'dev=/dev/spidev0.0,spispeed=8000' --read ~/'test3.bin' && sync
+  md5sum ~/'test1.bin' && md5sum ~/'test2.bin' && md5sum ~/'test3.bin'
+  rm -fv ~/'test2.bin' ~/'test3.bin' && sync
+===== Backup =====
+  * :!: Super-important to have a checksum-verified back-up to fall-back to when doing BIOS modifications
+  * **Back this up somewhere external before doing anything else**
+  * To be extra safe, also md5sum it and compare to above tests
+  * :!: ''spispeed=8000'' is necessary for reading from a ''W25Q64FV'' chip
+  sudo flashrom --programmer 'linux_spi':'dev=/dev/spidev0.0,spispeed=8000' --read ~/'backup-original.bin' && sync
+  md5sum ~/'test1.bin' && md5sum ~/'backup-original.bin'
+  rm -fv ~/'test1.bin' && sync
+===== Flash =====
+  * Change ''x'' to the location of the new ROM you want flashed
+  * :!: ''spispeed=8000'' is necessary for writing to a ''W25Q64FV'' chip
+  * :!: Change ''spispeed'' as-needed
+  sync && sudo flashrom --programmer 'linux_spi':'dev=/dev/spidev0.0,spispeed=8000' --write x
+====== me_cleaner ======
+  * TODO: Is ifdtool better for HAP bit?
+===== Get Source =====
+****
+  git clone -b 'master' 'https://github.com/corna/me_cleaner.git' ~/'me_cleaner' --depth '1'
+===== Check Original BIOS =====
+****
+  python ~/'me_cleaner/me_cleaner.py' --check ~/'backup-original.bin'
+===== Clean ME =====
+  * https://github.com/corna/me_cleaner/blob/master/me_cleaner.py#L478
+  * ''--descriptor'' caused an Acer laptop to not boot; remove if it causes problems
+  * ''--soft-disable-only'' can be used to set the MeAltDisable or HAP bit only and not remove partitions ((safest option if in doubt))
+  * Use no arguments in order to remove partitions and not touch MeAltDisable or HAP bit
+  python ~/'me_cleaner/me_cleaner.py' --soft-disable --descriptor --output ~/'me_cleaner-soft-disable-descriptor.bin' ~/'backup-original.bin'
+===== Flash Modified BIOS =====
+  * Change ''spispeed'' as-needed
+  sync && sudo flashrom --programmer 'linux_spi':'dev=/dev/spidev0.0,spispeed=8000' --write ~/'me_cleaner-soft-disable-descriptor.bin'
+===== Clean-up =====
+****
+  cd ~ && rm -Rf ~/'flashrom' && sync
+====== Verifying ME ======
+===== Windows =====
+  * TODO: Involves MEManuf and -VERBOSE flag
+===== Linux =====
+==== Coreboot ====
+  * Need Coreboot sources for some utilities
+  cd ~ && mkdir -p ~/'Projects' && rm -Rf ~/'Projects/coreboot/src' && git clone --branch 'master' --depth '1' 'https://github.com/coreboot/coreboot.git' ~/'Projects/coreboot/src' && sync
+=== intelmetool ===
+== Dependencies ==
+  * [[distros:fedora_workstation_gnome | Fedora Workstation]]
+  sudo dnf install 'pciutils-devel'
+== Compile ==
+****
+  cd ~/'Projects/coreboot/src/util/intelmetool' && make --jobs='3' && sync
+== Run ==
+****
+  cd ~/'Projects/coreboot/src/util/intelmetool' && sudo ~/'Projects/coreboot/src/util/intelmetool/intelmetool' --help
+=== ifdtool ===
+== Dependencies ==
+  * [[distros:fedora_workstation_gnome | Fedora Workstation]]
+  sudo dnf install 'pciutils-devel'
+== Compile ==
+****
+  cd ~/'Projects/coreboot/src/util/ifdtool' && make --jobs='3' && sync
+== Notes ==
+  * Can be used to set the HAP bit, similar to ''me_cleaner'''s ''--soft-disable-only''
+  * Can be used to dump information about ME on a BIOS image, good for checking if it's a valid dump like ''me_cleaner'''s ''--check'' option
+  * Can unlock R/W on chip areas much more thoroughly than ''me_cleaner''
+== Run ==
+****
+  cd ~/'Projects/coreboot/src/util/ifdtool' && ~/'Projects/coreboot/src/util/ifdtool/ifdtool' --help