diff options
Diffstat (limited to 'Documentation/tutorial')
8 files changed, 320 insertions, 0 deletions
diff --git a/Documentation/tutorial/flashing_firmware/ext_power.md b/Documentation/tutorial/flashing_firmware/ext_power.md new file mode 100644 index 0000000000..542ccfd934 --- /dev/null +++ b/Documentation/tutorial/flashing_firmware/ext_power.md @@ -0,0 +1,28 @@ +# Flashing firmware externally supplying direct power + +**WARNING:** Never use a high current rated power supply, like PC ATX power + supply. It'll literally melt your PCB traces on short circuit. + +On some mainboards the flash IC Vcc pin is connected to a diode, which prevents +powering the rest of the board. + +![][flash_ic_diode] + +Please have a look at the mainboard specific documentation for details. + +On those boards it's safe to use a programmer and supply power externally. + +**WARNING:** Verify that you apply the correct voltage! + +## USB programmer +USB programmers are usually current limited by the host USB hub. On USB 2.0 +ports the limit is 500mA, which is sufficient to power the flash. Those are +the best choice as they are stateless and have a fast power on reset cycle. + +## Single board computers (like BeagleBone Black / RPi) +Be careful when connecting a flash chip, especially when using a Pomona +test-clip. A short circuit or overcurrent (250mA) causes a brown-out reset, +resulting in a reboot of the running operating system (and possible loss of +remote shell). + +[flash_ic_diode]: flash_ic_diode.svg diff --git a/Documentation/tutorial/flashing_firmware/ext_standalone.md b/Documentation/tutorial/flashing_firmware/ext_standalone.md new file mode 100644 index 0000000000..3a676ce47c --- /dev/null +++ b/Documentation/tutorial/flashing_firmware/ext_standalone.md @@ -0,0 +1,23 @@ +# Flashing firmware standalone + +If none of the other methods work, there are three possibilities: + +## Desolder +You must remove or desolder the flash IC before you can flash it. +It's recommended to solder a socket in place of the flash IC. + +When flashing the IC, always connect all input pins. +If in doubt, pull /WP, /HOLD, /RESET and alike up towards Vcc. + +## SPI flash emulator +If you are a developer, you might want to use an [EM100Pro] instead, which sets +the onboard flash on hold, and allows to run custom firmware. +It provides a very fast development cycle without actually writing to flash. + +## SPI flash overwrite +It is possible to set the onboard flash on hold and use another flash chip. +Connect all lines one-to-one, except /HOLD. Pull /HOLD of the soldered flash IC +low, and /HOLD of your replacement flash IC high. + + +[EM100Pro]: https://www.dediprog.com/product/EM100Pro diff --git a/Documentation/tutorial/flashing_firmware/flash_ic_diode.svg b/Documentation/tutorial/flashing_firmware/flash_ic_diode.svg new file mode 100644 index 0000000000..22cd87277f --- /dev/null +++ b/Documentation/tutorial/flashing_firmware/flash_ic_diode.svg @@ -0,0 +1,61 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/PR-SVG-20010719/DTD/svg10.dtd"> +<svg width="4cm" height="3cm" viewBox="311 435 68 45" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"> + <g> + <g> + <rect style="fill: #ffffff" x="322.125" y="451.034" width="37.75" height="26.6444"/> + <rect style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x="322.125" y="451.034" width="37.75" height="26.6444"/> + <text font-size="4.51549" style="fill: #000000;text-anchor:middle;font-family:sans-serif;font-style:normal;font-weight:normal" x="341" y="465.734"> + <tspan x="341" y="465.734"></tspan> + </text> + </g> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="359.875" y1="456.784" x2="368.527" y2="456.784"/> + <text font-size="4.51549" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="348.75" y="457.909"> + <tspan x="348.75" y="457.909">VCC</tspan> + </text> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="359.763" y1="461.772" x2="368.652" y2="461.784"/> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="360.138" y1="466.872" x2="368.527" y2="466.909"/> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="360.277" y1="471.534" x2="368.402" y2="471.534"/> + <text font-size="4.51549" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="345.752" y="463.247"> + <tspan x="345.752" y="463.247">HOLD</tspan> + </text> + <line style="fill: none; fill-opacity:0; stroke-width: 0.2; stroke: #000000" x1="346.652" y1="459.159" x2="358.402" y2="459.159"/> + <text font-size="4.51549" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="349.752" y="468.247"> + <tspan x="349.752" y="468.247">CLK</tspan> + </text> + <text font-size="4.51549" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="353.502" y="472.997"> + <tspan x="353.502" y="472.997">DI</tspan> + </text> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="313.49" y1="456.922" x2="322.143" y2="456.922"/> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="313.378" y1="461.909" x2="322.268" y2="461.922"/> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="313.753" y1="467.009" x2="322.143" y2="467.047"/> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="313.893" y1="471.672" x2="322.018" y2="471.672"/> + <text font-size="4.51549" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="323.752" y="458.372"> + <tspan x="323.752" y="458.372">CS</tspan> + </text> + <text font-size="4.51549" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="324.127" y="468.497"> + <tspan x="324.127" y="468.497">WP</tspan> + </text> + <text font-size="4.51549" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="323.752" y="472.997"> + <tspan x="323.752" y="472.997">GND</tspan> + </text> + <text font-size="4.51549" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="324.127" y="463.497"> + <tspan x="324.127" y="463.497">DO</tspan> + </text> + <line style="fill: none; fill-opacity:0; stroke-width: 0.2; stroke: #000000" x1="330.852" y1="454.397" x2="323.902" y2="454.409"/> + <line style="fill: none; fill-opacity:0; stroke-width: 0.2; stroke: #000000" x1="330.802" y1="464.397" x2="323.852" y2="464.409"/> + </g> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="368.252" y1="456.797" x2="373.902" y2="456.784"/> + <g> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="374.027" y1="456.784" x2="374.027" y2="438.895"/> + <polyline style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" points="375.027,439.777 374.027,437.777 373.027,439.777 "/> + </g> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="314.277" y1="471.784" x2="314.277" y2="479.659"/> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="317.027" y1="479.659" x2="311.502" y2="479.672"/> + <g> + <line style="fill: none; fill-opacity:0; stroke-width: 1.2; stroke: #000000" x1="374.027" y1="443.284" x2="374.027" y2="447.434"/> + <polygon style="fill: #000000" points="372.027,447.434 374.027,451.434 376.027,447.434 "/> + <polygon style="fill: none; fill-opacity:0; stroke-width: 1.2; stroke: #000000" points="372.027,447.434 374.027,451.434 376.027,447.434 "/> + </g> + <line style="fill: none; fill-opacity:0; stroke-width: 1.2; stroke: #000000" x1="370.402" y1="452.032" x2="377.527" y2="452.032"/> +</svg> diff --git a/Documentation/tutorial/flashing_firmware/flash_ic_no_diode.svg b/Documentation/tutorial/flashing_firmware/flash_ic_no_diode.svg new file mode 100644 index 0000000000..543c9262df --- /dev/null +++ b/Documentation/tutorial/flashing_firmware/flash_ic_no_diode.svg @@ -0,0 +1,55 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/PR-SVG-20010719/DTD/svg10.dtd"> +<svg width="4cm" height="3cm" viewBox="311 435 65 45" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"> + <g> + <g> + <rect style="fill: #ffffff" x="322.124" y="451.034" width="37.75" height="26.6444"/> + <rect style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x="322.124" y="451.034" width="37.75" height="26.6444"/> + <text font-size="4.51556" style="fill: #000000;text-anchor:middle;font-family:sans-serif;font-style:normal;font-weight:normal" x="340.999" y="465.734"> + <tspan x="340.999" y="465.734"></tspan> + </text> + </g> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="359.874" y1="456.784" x2="368.528" y2="456.784"/> + <text font-size="4.51556" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="348.75" y="457.91"> + <tspan x="348.75" y="457.91">VCC</tspan> + </text> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="359.762" y1="461.772" x2="368.652" y2="461.784"/> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="360.138" y1="466.872" x2="368.528" y2="466.91"/> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="360.278" y1="471.534" x2="368.402" y2="471.534"/> + <text font-size="4.51556" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="345.752" y="463.246"> + <tspan x="345.752" y="463.246">HOLD</tspan> + </text> + <line style="fill: none; fill-opacity:0; stroke-width: 0.2; stroke: #000000" x1="346.652" y1="459.16" x2="358.402" y2="459.16"/> + <text font-size="4.51556" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="349.752" y="468.246"> + <tspan x="349.752" y="468.246">CLK</tspan> + </text> + <text font-size="4.51556" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="353.502" y="472.996"> + <tspan x="353.502" y="472.996">DI</tspan> + </text> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="313.49" y1="456.922" x2="322.142" y2="456.922"/> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="313.378" y1="461.91" x2="322.268" y2="461.922"/> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="313.752" y1="467.01" x2="322.142" y2="467.046"/> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="313.892" y1="471.672" x2="322.018" y2="471.672"/> + <text font-size="4.51556" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="323.752" y="458.372"> + <tspan x="323.752" y="458.372">CS</tspan> + </text> + <text font-size="4.51556" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="324.128" y="468.496"> + <tspan x="324.128" y="468.496">WP</tspan> + </text> + <text font-size="4.51556" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="323.752" y="472.996"> + <tspan x="323.752" y="472.996">GND</tspan> + </text> + <text font-size="4.51556" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="324.128" y="463.496"> + <tspan x="324.128" y="463.496">DO</tspan> + </text> + <line style="fill: none; fill-opacity:0; stroke-width: 0.2; stroke: #000000" x1="330.852" y1="454.396" x2="323.902" y2="454.41"/> + <line style="fill: none; fill-opacity:0; stroke-width: 0.2; stroke: #000000" x1="330.802" y1="464.396" x2="323.852" y2="464.41"/> + </g> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="368.252" y1="456.796" x2="373.902" y2="456.784"/> + <g> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="374.028" y1="456.784" x2="374.028" y2="438.896"/> + <polyline style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" points="375.028,439.778 374.028,437.778 373.028,439.778 "/> + </g> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="314.278" y1="471.784" x2="314.278" y2="479.66"/> + <line style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" x1="317.028" y1="479.66" x2="311.502" y2="479.672"/> +</svg> diff --git a/Documentation/tutorial/flashing_firmware/index.md b/Documentation/tutorial/flashing_firmware/index.md new file mode 100644 index 0000000000..da3d7f098f --- /dev/null +++ b/Documentation/tutorial/flashing_firmware/index.md @@ -0,0 +1,111 @@ +# Flashing firmware tutorial + +Updating the firmware is possible using the **internal method**, where the updates +happen from a running system, or using the **external method**, where the system +is in a shut down state and an external programmer is attached to write into the +flash IC. + +## Contents + +* [Flashing internally](int_flashrom.md) +* [Flashing firmware standalone](ext_standalone.md) +* [Flashing firmware externally supplying direct power](ext_power.md) +* [Flashing firmware externally without supplying direct power](no_ext_power.md) + +## General advice + +* It's recommended to only flash the BIOS region. +* Always verify the firmware image. +* If you flash externally and have transmission errors: + * Use short wires + * Reduce clock frequency + * Check power supply + * Make sure that there are no other bus masters (EC, ME, SoC, ...) + +## Internal method + +This method using [flashrom] is available on many platforms, as long as they +aren't locked down. + +There are various protection schemes that make it impossible to modify or +replace a firmware from a running system. coreboot allows to disable these +mechanisms, making it possible to overwrite (or update) the firmware from a +running system. + +Usually you must use the **external method** once to install a retrofitted +coreboot and then you can use the **internal method** for future updates. + +There are multiple ways to update the firmware: +* Using flashrom's *internal* programmer to directly write into the firmware + flash IC, running on the target machine itself +* A proprietary software to update the firmware, running on the target machine + itself +* A UEFI firmware update capsule + +More details on flashrom's +* [internal programmer](int_flashrom.md) + +## External method + +External flashing is possible on many platforms, but requires disassembling +the target hardware. You need to buy a flash programmer, that +exposes the same interface as your flash IC (likely SPI). + +Please also have a look at the mainboard-specific documentation for details. + +After exposing the firmware flash IC, read the schematics and use one of the +possible methods: + +* [Flashing firmware standalone](ext_standalone.md) +* [Flashing firmware externally supplying direct power](ext_power.md) +* [Flashing firmware externally without supplying direct power](no_ext_power.md) + +**WARNING:** Using the wrong method or accidentally using the wrong pinout might + permanently damage your hardware! + +**WARNING:** Do not rely on dots *painted* on flash ICs to orient the pins! +Any dots painted on flash ICs may only indicate if they've been tested. Dots +that appear in datasheets to indicate pin 1 correspond to some kind of physical +marker, such as a drilled hole, or one side being more flat than the other. + +## Using a layout file +On platforms where the flash IC is shared with other components you might want +to write only a part of the flash IC. On Intel for example there are IFD, ME and +GBE which don't need to be updated to install coreboot. +To make [flashrom] only write the *bios* region, leaving Intel ME and Intel IFD +untouched, you can use a layout file, which can be created with ifdtool and a backup +of the original firmware. + +```bash +ifdtool -f rom.layout backup.rom +``` + +and looks similar to: + +``` +00000000:00000fff fd +00500000:00bfffff bios +00003000:004fffff me +00001000:00002fff gbe +``` + +By specifying *-l* and *-i* [flashrom] writes a single region: +```bash +flashrom -l rom.layout -i bios -w coreboot.rom -p <programmer> +``` + +## Using an IFD to determine the layout +flashrom version 1.0 supports reading the layout from the IFD (first 4KiB of +the ROM). You don't need to manually specify a layout it, but it only works +under the following conditions: + +* Only available on Intel ICH7+ +* There's only one flash IC when flashing externally + +```bash +flashrom --ifd -i bios -w coreboot.rom -p <programmer> +``` + +**TODO** explain FMAP regions, normal/fallback mechanism, flash lock mechanisms + +[flashrom]: https://www.flashrom.org/Flashrom diff --git a/Documentation/tutorial/flashing_firmware/int_flashrom.md b/Documentation/tutorial/flashing_firmware/int_flashrom.md new file mode 100644 index 0000000000..982aca287d --- /dev/null +++ b/Documentation/tutorial/flashing_firmware/int_flashrom.md @@ -0,0 +1,19 @@ +# Flashing firmware internally + +**WARNING:** If you flash a broken firmware and have no recovery mechanism, you + must use the **external method** to flash a working firmware again. + +## Using flashrom +This method does only work on Linux, if it isn't locked down. +You may also need to boot with `iomem=relaxed` in the kernel command +line if CONFIG_IO_STRICT_DEVMEM is set. + + +For more details please also check [flashrom's wiki]. +Use the programmer *internal* to flash *coreboot.rom* internally: + +```bash +flashrom -p internal -w coreboot.rom +``` + +[flashrom's wiki]: https://www.flashrom.org/Flashrom diff --git a/Documentation/tutorial/flashing_firmware/no_ext_power.md b/Documentation/tutorial/flashing_firmware/no_ext_power.md new file mode 100644 index 0000000000..b97ba4cc7a --- /dev/null +++ b/Documentation/tutorial/flashing_firmware/no_ext_power.md @@ -0,0 +1,22 @@ +# Flashing firmware externally supplying no power + +On some mainboards the flash IC's Vcc pin is connected to the internal +power-rail, powering the entire board if the flash IC is powered externally. +Likely it powers other chips which access the flash IC, preventing the external +programmer from reading/writing the chip. It also violates the components' +power sequence, bringing the ICs into an undefined state. + +![][flash_ic_no_diode] + +Please have a look at the mainboard specific documentation for details. + +On those boards it's recommended to use a programmer without supplying power +externally. + +The key to read and write the flash IC is to put the machine into *S3* sleep- +state or *S5* sleep-state *maybe* with Wake-On-LAN enabled. +Another option that sometimes works is to keep the device in reset. This method requires +knowledge of the board schematics and might require hardware modifications. +Use a multimeter to make sure the flash IC is powered in those sleep states. + +[flash_ic_no_diode]: flash_ic_no_diode.svg diff --git a/Documentation/tutorial/index.md b/Documentation/tutorial/index.md index 8b3d88aaba..384f84084e 100644 --- a/Documentation/tutorial/index.md +++ b/Documentation/tutorial/index.md @@ -4,3 +4,4 @@ * [Part 2: Submitting a patch to coreboot.org](part2.md) * [Part 3: Writing unit tests](part3.md) * [Managing local additions](managing_local_additions.md) +* [Flashing firmware](flashing_firmware/index.md) |
