Openembedded/Yocto hardware support layer for TQ-Systems x86 COMs

This README file contains information on the contents of the meta-tqmx86 layer. This layer provides support for TQ-Systems COMs (Computer-on-Modules) with x86 CPU.

Dependencies

This layer depends on a number of base layers, which are listed in the following.

The correct branch matching the Yocto version must be checked out for each layer. The supported Yocto version is "scarthgap". Historical branches for building against older Yocto versions can also be found in this repository.

• poky

  URL: https://git.yoctoproject.org/cgit.cgi/poky/

• meta-intel

  URL: http://git.yoctoproject.org/cgit/cgit.cgi/meta-intel

Patches

Please submit patches against the meta-tqmx86 layer to the TQ-Systems Linux team ([email protected]) or use Github's collaboration features.

Build setup

In order to use this layer you need to make the build system aware of it.

Assuming the all layers exist in a subdir sources at the top-level of your Yocto build tree, you can add it to the build system by adding the location of the meta-tqmx86 layer to bblayers.conf along with any other layers needed, e.g.:

BBLAYERS ?= " \
  ${BSPDIR}/sources/poky/meta \
  ${BSPDIR}/sources/poky/meta-poky \
  ${BSPDIR}/sources/meta-intel \
  ${BSPDIR}/sources/meta-tqmx86 \
"

Supported hardware

All TQ-Systems x86 hardware listed in the following is supported by the MACHINE configuration "intel-x86-64-tqmx86". The core-image-base and the DISTRO "poky" are the recommended starting point for customization of the BSP.

The "intel-x86-64-tqmx86" machine uses the linux-yocto kernel recipe by default. A realtime kernel can be built by setting PREFERRED_PROVIDER_virtual/kernel = "linux-yocto-rt" in local.conf or a custom distro.

For many COMs, variants with alternative CPUs are available, and different mainboards with the same form factor can be used. The boards listed in the following table have been used for testing the Yocto BSP.

	COM	Mainboard	CPU	Form factor
b	TQMx50UC		Intel Core (5th generation)	COM Express Compact Type 6
b	TQMx60EB		Intel Core (6th generation)	COM Express Basic Type 6
b	TQMx70EB		Intel Core (7th generation)	COM Express Basic Type 6
b	TQMx80UC		Intel Core (8th generation)	COM Express Compact Type 6
b	TQMx110EB		Intel Core (11th generation)	COM Express Basic Type 6
y	TQMx120HC/PC/UC	MB-COME6-4	Intel Core (12th generation)	COM Express Compact Type 6
p	TQMx130HC/PC/UC		Intel Core (13th generation)	COM Express Compact Type 6
b	TQMxE38C		Intel Atom E3800	COM Express Compact Type 6
b	TQMxE38M		Intel Atom E3800	COM Express Mini Type 10
b	TQMxE39C1/2		Intel Atom E3900	COM Express Compact Type 6
b	TQMxE39M		Intel Atom E3900	COM Express Mini Type 10
b	TQMxE39S		Intel Atom E3900	SMARC 2.0/2.1
b	TQMxE40C1/2		Intel Atom x6000	COM Express Compact Type 6
b	TQMxE40M		Intel Atom x6000	COM Express Mini Type 10
y	TQMxE40S	MB-SMARC-3	Intel Atom x6000	SMARC 2.1
b	TQMxE41S		Intel Atom x7000E	SMARC 2.1

	Support status
y	supported
b	build tested only
p	prerelease

Known issues

• The both-edges IRQ trigger of the TQMx86 GPIO driver will report multiple falling or rising edge events in a row instead of alternating between the two when the edges are received faster than they can be reported
• A warning with backtrace from the i915 driver is printed to the kernel log when booting with LVDS enabled
• No default asound.state is provided. Manual mixier configuration (amixer/ alsamixer) is required to enable audio recording from Line-in or Mic inputs.
• After switching the framebuffer to graphical mode (using fb-test or similar), it is not possible to return to text mode. Commands like chvt or restarting getty on the VTs will hang.
• In some configurations, possibly depending on the display resolution, fb-test shows a cut-off test image instead of filling the whole screen.

The following issues are caused by the BIOS and not the Linux BSP:

• TQMxE40S: The eSPI UART controller of the MB-SMARC-3 (SER4/SER5) can't be used
• TQMxE40S: In the default BIOS configuration, Linux will warn about a deferred driver probe after boot. To avoid the warning, disable SPI0 or set DMA2 to "host owned" in the BIOS setup.
• TQMx110EB/TQMx120UC: The USB controller may stop working after reboot with some BIOS versions.