View source for OpenSTLinux distribution

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{{ArticleMainWriter|DenisH}}

{{ArticleApprovedVersion|DenisH| NathalieS, ChristopheM | RomualdJ - 27Feb'18  | Philip S. - 28Jun'18 - 8358| 28Jun'18 }}

[[Category:OpenSTLinux distribution|00]]
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==What is the OpenSTLinux distribution?==
The OpenSTLinux distribution, running on the Arm<sup>&reg;</sup> Cortex<sup>&reg;</sup>-A processor(s), is a sub-part of the [[STM32MPU Embedded Software distribution]].
[[File:OpenSTLinux distribution.png|thumb|200px|link=]]

OpenSTLinux is a Linux<sup>&reg;</sup> distribution based on the [[OpenEmbedded]] build framework.<br>

It includes the following collection of software components:
* [[OpenSTLinux BSP architecture overview|OpenSTLinux BSP]] (OP-TEE secure OS, boot chain and Linux kernel)
* Application frameworks such as the following Linux application frameworks (non-exhaustive list):
** [[Wayland Weston overview|Wayland-Weston]] as a display/graphic framework
** [[GStreamer_overview|Gstreamer]] as a multimedia framework
** [[ALSA overview|Advanced Linux Sound Architecture (ALSA)]] libraries

As explained in the [[OpenEmbedded]] article, the files used to build an image are stored in layers that come from different sources, and that are configured for this image. <br>
Only layers specific to the OpenSTLinux distribution (for example the OpenSTLinux Board Support Package layer) are detailed in the [[#Layers|Layers]]  chapter below. Community layers referenced in this article are not listed.
{{ReviewsComments| JLD (product maketing): today:The diagram inludes Yocto while not described into the above comment. That might drive some confusion..Is Yocto included into the distro or not??}}


The [[#Machines|Machines]] chapter introduces the machine metadata (the information needed to build a kernel for specific target boards), while the [[#Images|Images]] chapter specifies the images that contain the information needed to build the user space. The [[#Distros|Distros]] chapter describes the available distros configurations.

==Software architecture overview==
The figure below gives an overview of the [[OpenSTLinux architecture overview|OpenSTLinux architecture]]. You can obtain more details by clicking on one of the sub-levels.<br>

The '''Linux application frameworks''' (or Linux user space components) that rely on the [[OpenSTLinux BSP architecture overview|OpenSTLinux BSP]], mainly come from open-source communities.

OpenEmbedded core components (community layers) combined with STMicroelectronics-specific layers (for example the BSP layer) give a consistent starting point to develop customer applications based on a standardized interface.

{{:OpenSTLinux architecture overview}}

==OpenSTLinux concept==

To build an OpenSTLinux based software, a combination of machine, image and distro must be selected.<br>
Available machines, images and distros are listed below.

More information on how to compile and use an OpenSTLinux distribution can be found in the '''Distribution Package''' articles available in [[:category:Distribution Package]].

===Layers===
This chapter describes the layers developed by STMicroelectonics.
{{ReviewsComments| JLD (product marketing): Today: I think there is a different hirarchy to take into account between Layers / machine & image & distro... Machine should not be 3.1.1, image 3.1.2 etc..}}

STMicroelectronics' strategy is to organize the layers in order to split BSP descriptions from applications and frameworks.<br>
By doing this, any BSP can be combined with any framework, or no framework at all.
 
{| class="wikitable" style="text-align: left; border-style: solid; border-width: 3px; border-color:#00C0FF"
|-
! style="border-style: solid; border-width: 3px; border-color:#00C0FF"  align="center" valign="center"| Layer
! style="border-style: solid; border-width: 3px; border-color:#00C0FF"  align="center" valign="center"| Description
|-
| meta-st-stm32mp || BSP Layer for stm32mp
|-
| meta-st-openstlinux || OpenSTLinux layer - framework/image settings
|}

For the detailed content of the layers, please check [[STM32MP15_OpenSTLinux_release_note#Detailed delivery content]]

In addition, in OpenSTLinux distribution, a layer (meta-st-stm32mp-addons) has been created to manage STM32CubeMX integration.<br>
If necessary, you can also create your own layer. The procedure to do so is explained in [[How_to_create_a_new_open_embedded_layer]].

{| class="wikitable" style="text-align: left; border-style: solid; border-width: 3px; border-color:#00C0FF"
|-
! style="border-style: solid; border-width: 3px; border-color:#00C0FF"  align="center" valign="center"| Layer
! style="border-style: solid; border-width: 3px; border-color:#00C0FF"  align="center" valign="center"| Description
|-
| meta-st-stm32mp-addons || BSP Layer addons for stm32mp (CubeMX Machine)
|-
| meta-my-custo-layer || framework addons/customization
|}

===Machines===
{| class="wikitable" style="text-align: left; border-style: solid; border-width: 3px; border-color:#00C0FF"
|-
! style="border-style: solid; border-width: 3px; border-color:#00C0FF"  align="center" valign="center"| Machine
! style="border-style: solid; border-width: 3px; border-color:#00C0FF"  align="center" valign="center"| Description
|-
| stm32mp1 || Machine configuration for STM32MP1 microprocessor device boards
|-
| stm32mp1-eval || Machine configuration for STM32MP1 evaluation board
|-
| stm32mp1-disco || Machine configuration for STM32MP1 disco board
|}

===Images===
{| class="wikitable" style="text-align: left; border-style: solid; border-width: 3px; border-color:#00C0FF"
|-
! style="border-style: solid; border-width: 3px; border-color:#00C0FF"  align="center" valign="center "| Image
! style="border-style: solid; border-width: 3px; border-color:#00C0FF"  align="center" valign="center "| Description
|-
!! colspan="2" style="background-color: Grey;"| Official images
|-
| st-image-weston || OpenSTLinux weston image with basic Wayland support (if enabled in distro)
|-
!! colspan="2" style="background-color: Grey;"| Supported images
|-
| st-image-core || OpenSTLinux core image
|-
!! colspan="2" style="background-color: Grey;"| Proposed images as example only
|-
| st-example-image-qt || ST example of image based on QT framework
|-
| st-example-image-x11 || ST example of image based on X11
|-
| st-example-image-xfce || ST example of image based on XFCE framework
|-
| st-example-image-gtk || ST example of image based on GTK framework
|}

===Distros===

For further details on distributions (distros), read "Creating a distribution"  <ref> http://www.yoctoproject.org/docs/2.4/mega-manual/mega-manual.html#creating-your-own-distribution Creating a distribution </ref>

{| class="wikitable" style="text-align: left; border-style: solid; border-width: 3px; border-color:#00C0FF"
|-
! style="border-style: solid; border-width: 3px; border-color:#00C0FF"  align="center" valign="center "| Distro
! style="border-style: solid; border-width: 3px; border-color:#00C0FF"  align="center" valign="center "| Description
|-
| openstlinux-eglfs || OpenSTLinux featuring eglfs - no X11, no Wayland
|-
| openstlinux-weston || OpenSTLinux featuring Weston/Wayland
|-
| openstlinux-x11 || OpenSTLinux featuring X11
|-
| nodistro || *** DEFAULT OPENEMBEDDED SETTING : DISTRO is not defined *** 
|}

===Reference source code===

The TF-A, U-Boot, OP-TEE and kernel components have been configured by default to use '''tarball + patches''' for source code.

If you prefer to use '''github'''<sup>&reg;</sup> as a source code reference, you need to update your local.conf file 

Refer to the section ‘Configure STM32MP default version to github’ in local.conf :

 # =========================================================================
 # Configure STM32MP default version to github
 # =========================================================================
 #STM32MP_SOURCE_SELECTION_pn-linux-stm32mp = "github"
 #STM32MP_SOURCE_SELECTION_pn-optee-os-stm32mp = "github"
 #STM32MP_SOURCE_SELECTION_pn-tf-a-stm32mp = "github"
 #STM32MP_SOURCE_SELECTION_pn-u-boot-stm32mp = "github"

Then just uncomment the line to switch the component to github<sup>&reg;</sup> for source code.

==How to get the software for this distribution==
The OpenSTLinux distribution is available through the three Packages (Starter, Developer, and Distribution) of the [[STM32MPU Embedded Software distribution|STM32MPU Embedded Software distribution]].

==References==
<references/>