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CHIPSEC gets support for Nine more ACPI tables

Lots of news are filled with news about the latest  version of CHIPSEC released. I don’t see that, but there are some interesting new checkins w/r/t ACPI support:

ACPI_TABLE_SIG_BGRT = ‘BGRT’
ACPI_TABLE_SIG_LPIT = ‘LPIT’
ACPI_TABLE_SIG_ASPT = ‘ASPT’
+ACPI_TABLE_SIG_FIDT = ‘FIDT’
+ACPI_TABLE_SIG_HEST = ‘HEST’
+ACPI_TABLE_SIG_BERT = ‘BERT’
+ACPI_TABLE_SIG_ERST = ‘ERST’
+ACPI_TABLE_SIG_EINJ = ‘EINJ’
+ACPI_TABLE_SIG_TPM2 = ‘TPM2’
+ACPI_TABLE_SIG_WSMT = ‘WSMT’
+ACPI_TABLE_SIG_DBG2 = ‘DBG2’
+ACPI_TABLE_SIG_NHLT = ‘NHLT’
+ACPI_TABLE_SIG_MSCT = ‘MSCT’
+ACPI_TABLE_SIG_RASF = ‘RASF’
+ACPI_TABLE_SIG_SPMI = ‘SPMI’
+ACPI_TABLE_SIG_OEM1 = ‘OEM1’
+ACPI_TABLE_SIG_OEM2 = ‘OEM2’
+ACPI_TABLE_SIG_OEM3 = ‘OEM3’
+ACPI_TABLE_SIG_OEM4 = ‘OEM4’
+ACPI_TABLE_SIG_NFIT = ‘NFIT’

as well as some new SGX support… Fun!

https://github.com/chipsec/chipsec/commits/master

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Lenovo ACPI bug – affects X1C6, X1Y3, X280, T480s, T480, T580, P52s, possibly more. ‎

“This bug deserves more attention than it is currently receiving. It should be pinned in every forum with an affected machine, so that owners of those machines will be aware that it exists. It is currently squirreled away in the T series forum, under the outdated title “T480s – ACPI bug”. I have asked that the title be updated and received no response, which is why I’m posting this here.[…]

There’s a bug in the ACPI tables that affects all of the machines listed in the title. The bug causes heavy CPU usage on one thread due to frequent ACPI interrupts. The symptoms are a slow system, and high CPU temperatures (idles around 65 degrees Celsius). Some operating systems may mitigate the symptoms, but the bug is present regardless.

The following circumstances trigger it:
-powering on the laptop
-waking from suspend (and possibly hibernate – untested)

The following actions prevent it:
-reboot the laptop (temporary fix)
-disable thunderbolt in the UEFI settings (permanent fix – with latest UEFI updates)

The official UEFI update changelogs for all of these machines make explicit mention of this issue: “-(Fix) Fix an issue where system may become hot by system interrupts when Thundrebolt is disabled in ThinkPad Setup – Security – I/O Port Access.”[…]

https://forums.lenovo.com/t5/ThinkPad-X-Series-Laptops/ACPI-bug-affects-X1C6-X1Y3-X280-T480s-T480-T580-P52s-possibly/td-p/4084521

https://forums.lenovo.com/t5/ThinkPad-T400-T500-and-newer-T/T480s-ACPI-bug/m-p/4064963#M124889

https://forums.lenovo.com/t5/ThinkPad-T400-T500-and-newer-T/T480s-ACPI-bug/m-p/4067181#M124936

https://download.lenovo.com/pccbbs/mobiles/n22ur05w.txt

 

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ACPI Debugging: ACPI AML Debugger in Ubuntu 18.04

Alex Hung of Canonical — and one of the FirmWare Test Suite developers — has a new blog post, showing how to debug ACPI on recent builds of Ubuntu:

ACPICA is a project that provides an operating system (OS)-independent reference implementation. It also contains a list of utilities such as ASL compiler (iasl), acpiexec (an AML emulator) and so on. However, debugging AML on Linux in real time wasn’t provided in ACPICA … until Linux Kernel 4.13. The aml-debugger.txt the instruction of how to enable AML debugger, is available at Documentation/acpi/ in Linux kernel source code. In short, two things are required to run AML debugging. […] While compiling a custom-build kernel with the above two config is nothing new to kernel developers, it is often inconvenient for firmware developers who need to verify ACPI implementation in their firmware. Fortunately, Ubuntu 18.04 (x64) enables these two config by default, and one can run acpidbg on Ubuntu 18.04 – even on Ubuntu Live from USB too! Executing acpidbg on Ubuntu 18.04 is very straight-forward[…]

http://alexhungdmz.blogspot.ca/2018/05/acpi-debugging-1-acpi-aml-debugger-in.html

See also:

https://raw.githubusercontent.com/torvalds/linux/master/Documentation/acpi/aml-debugger.txt
https://www.kernel.org/doc/Documentation/acpi/debug.txt
https://wiki.ubuntu.com/DebuggingACPI
https://wiki.ubuntu.com/Kernel/Reference/ACPITricksAndTips
https://01.org/linux-acpi/documentation/debug-how-isolate-linux-acpi-issues
https://lwn.net/Articles/237085/

 

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Lai (Lux ACPI Implementation): AML for Lux, a Unix-like OS

Lux is a new Unix-like operating written for the PC, aiming for high performance with minimal requirements. Lai, the Lux ACPI Implementation, is an implementation of ACPI’s Machine Language (AML) written for use with lux, but with portability in mind. As such, lai is portable and OS-independent. It depends on a few OS-specific functions, and so a small layer is written for each OS lai is to be used with, and this requires no changes to the core code of lai.

https://github.com/omarrx024/lux
https://omarrx024.github.io/

https://github.com/omarrx024/lai
https://omarrx024.github.io/docs/lai.html

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AHCI BIOS Security Extension

This software is useful if:
* you have a (probably self-encrypting) hard disk / solid state drive that supports the (S)ATA SECURITY command set

* you want to boot from this drive.
* your motherboard’s BIOS does not support asking the user for a hard disk password at startup
* you don’t want to buy a new motherboard.
* the hard disk controller of your motherboard supports AHCI.

http://www.tb-kaiser.de/ahci_sbe/

https://github.com/TobiasKaiser/ahci_sbe

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