209 lines
8.4 KiB
Markdown
209 lines
8.4 KiB
Markdown
---
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title: HP EliteBook 820 G2
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x-toc-enable: true
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...
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**[PLEASE READ THESE INSTRUCTIONS BEFORE INSTALLING](../../news/safety.md),
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OR YOU MIGHT BRICK YOUR MACHINE: [SAFETY PRECAUTIONS](../../news/safety.md)**
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<div class="specs">
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<center>
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<img tabindex=1 alt="HP EliteBook 820 G2" class="p" src="https://av.libreboot.org/hp820g2/hp820g2.jpg" /><span class="f"><img src="https://av.libreboot.org/hp820g2/hp820g2.jpg" /></span>
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<img tabindex=1 alt="HP EliteBook 820 G2" class="p" src="https://av.libreboot.org/hp820g2/hp820g2_lid.jpg" /><span class="f"><img src="https://av.libreboot.org/hp820g2/hp820g2_lid.jpg" /></span>
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<br/>
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<img tabindex=1 alt="HP EliteBook 820 G2" class="p" src="https://av.libreboot.org/hp820g2/hp820g2_ports1.jpg" /><span class="f"><img src="https://av.libreboot.org/hp820g2/hp820g2_ports1.jpg" /></span>
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<img tabindex=1 alt="HP EliteBook 820 G2" class="p" src="https://av.libreboot.org/hp820g2/hp820g2_ports2.jpg" /><span class="f"><img src="https://av.libreboot.org/hp820g2/hp820g2_ports2.jpg" /></span>
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<br/>
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</center>
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| ***Specifications*** | |
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|----------------------------|------------------------------------------------|
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| **Manufacturer** | HP |
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| **Name** | EliteBook 820 G2 |
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| **Variants** | EliteBook 820 G2 |
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| **Released** | 2014 |
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| **Chipset** | 5th gen (Broadwell, SoC) |
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| **CPU** | Intel i5-5200U, i5-5300U, i7-5500U, i7-5600U |
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| **Graphics** | Intel HD 5500 graphics (libre initialisation) |
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| **Display** | 14" 1366x768 or 1920x1080 TFT |
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| **Memory** | Two slots, max 16GB/slot (32GB), DDR3/SODIMM |
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| **Architecture** | x86_64 |
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| **EC** | SMSC MEC1324 in main boot flash |
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| **Original boot firmware** | HP UEFI firmware |
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| **Intel ME/AMD PSP** | Present. Can be disabled with me_cleaner. |
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| **Flash chip** | SOIC-8 16MiB 128Mbit, 12MiB usable by coreboot |
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```
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W+: Works without vendor firmware;
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N: Doesn't work;
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W*: Works with vendor firmware;
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U: Untested;
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P+: Partially works;
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P*: Partially works with vendor firmware
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```
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| ***Features*** | |
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|---------------------------------------------------|----|
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| **Internal flashing with original boot firmware** | N |
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| **Display (if Intel GPU)** | W+ |
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| **Audio** | W+ |
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| **RAM Init** | W+ |
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| **External output** | W+ |
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| **Display brightness** | W+ |
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| ***Payloads supported*** | |
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|---------------------------|-----------|
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| **GRUB** | Works |
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| **SeaBIOS** | Works |
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| **SeaBIOS with GRUB** | Works |
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</div>
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Brief board info:
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Full hardware specifications can be found on HP's own website:
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<https://support.hp.com/gb-en/document/c04543492>
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Introduction
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============
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Please build this from source with lbmk:
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./mk -b coreboot hp820g2_12mb
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More information is available in the [build guide](../build/), including how
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to install build dependencies.
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Pre-compiled images now possible!
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--------------------------------
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From Libreboot 20241206 **revision 8** onwards, pre-compiled ROM images *are*
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now available. Previous releases excluded images for this board, because vendor
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file insertion was not reproducible, so you would get checksum errors. This
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has been fixed with the following patch:
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<https://browse.libreboot.org/lbmk.git/commit/?id=e8799310db26df89720e8476a701f1904932234b>
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The refcode is inserted uncompressed, whereas upstream uses LZMA compression.
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We can't predict how the implementation will change in the future, and any
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behavioural changes would probably affect the checksum on insertion. Older
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releases also didn't handle `rmodtool` on refcode insertion, which is used
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to make the file relocatable in CBFS. See:
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<https://doc.coreboot.org/lib/rmodules.html>
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As of Libreboot 20241206 rev8, you can now use pre-compiled release images
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and [insert vendor files](ivy_has_common.md).
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The lack of refcode compression costs about 110KB, because the refcode file is
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about 180KB uncompressed, but would be about 70KB compressed in flash. We
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insert it uncompressed, so it's 180KB in flash. This is a small sacrifice,
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considering that you still have about 10MB of unused flash space left, at least
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as of the 20241206 rev8 release.
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HP Sure Start
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=============
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There is a 16MB flash and a 2MB flash. Read this page for info:
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<https://doc.coreboot.org/mainboard/hp/hp_sure_start.html>
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The page makes it seem more complicated than necessary, from a user's point
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of view. What you really need to do is just erase the 2MB flash IC, and flash
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only the first 12MB of the 16MB flash IC. A photo is shown below. Consult
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the [SPI flashing guide](../install/spi.md) and act as if you were flashing,
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but leave out `-w libreboot.rom` (don't write an image), and instead
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use the `--erase` option, with your clip connected to the private flash (2MB
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flash IC).
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You might want to dump the private flash first, just in case (use `-r priv.rom`
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or whatever filename you want to dump to, and take two dumps, ensuring that
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the hashes match); one dump for the first erase, and another for the next
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erase. If they match, then the erase was likely a success. The private (2MB)
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flash is inaccessible from your OS. The
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system stores hashes of the IFD, GbE and a copy of IFD/GbE in private flash,
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restoring them if they were modified, but erasing the private flash disables
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this security mechanism.
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Coreboot has its own page about this machine:
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<https://doc.coreboot.org/mainboard/hp/elitebook_820_g2.html>
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Make sure to read and understand all of this first, before attempting
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the Libreboot installation, because it's also important when updating
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Libreboot later on.
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Installation of Libreboot
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=========================
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Make sure to set the MAC address in the flash:
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[Modify MAC addresses with nvmutil](../install/nvmutil.md).
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Refer to the [Libreboot flashing guides](../install/spi.md)
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Here are the flash ICs:
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When you flash the 12MB image, please do the following with it:
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dd if=/dev/zero of=4mb.bin bs=4M count=1
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cat libreboot.rom 4mb.bin > libreboot16.rom
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Be careful: do not fully flash `libreboot16.rom`
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Flash it like this, instead:
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```
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flashprog -p PROGRAMMER --ifd -i gbe -w libreboot16.rom --noverify-all
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flashprog -p PROGRAMMER --ifd -i bios -w libreboot16.rom --noverify-all
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flashprog -p PROGRAMMER --ifd -i me -w libreboot16.rom --noverify-all
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flashprog -p PROGRAMMER --ifd -i fd -w libreboot16.rom --noverify-all
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```
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Replace `PROGRAMMER` according to whichever flasher you're using. You could
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also replace it with `internal`, if later flashing internally to update an
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existing Libreboot installation.
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If you're flashing internally, add `--noverify-all` to the flashprog
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command.
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To erase the 2MB flash, do this:
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```
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flashprog -p PROGRAMMER --erase
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```
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Refer generally to the [main flashing guide](../install/) and to
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the [external flashing guide](../install/spi.md) so that you can learn how
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to actually flash it.
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TPM 2.0 potentially supported
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==============================
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The onboard TPM is an SLB 9660, which supports TPM 1.2 but it is known to be
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compatible with TPM 2.0 via firmware upgrade. Although not yet tested, we have
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some notes about that here:
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[../../tasks/#hp-820-g2-tpm](../../tasks/#hp-820-g2-tpm)
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Not yet used meaningfully by Libreboot itself, but the TPM can be used to
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implement things like measured boot.
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References
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==========
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See: <https://doc.coreboot.org/soc/intel/broadwell/blobs.html>
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Libreboot's build system automatically pulls down the MRC/refcode files, and
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modifies the refcode to enable the onboard Intel Gigabit Ethernet (GbE). You
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don't need to mess with this at all, when you build Libreboot yourself.
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You can see how this works, by looking at the patch which added 820 G2 support:
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<https://browse.libreboot.org/lbmk.git/commit/?id=401c0882aaec059eab62b5ce467d3efbc1472d1f>
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Yay. If you see this boot screen, you should be proud. This is a really
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hard machine to flash.
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