Hi all,
I am sorry that I didn't have enough discussion about why new window
system code is needed for Tizen on mesa.
This is a brief architecture of Tizen Window System.
+--------------------------------------------------------------------------------------------------+
| [Tizen Window System Architecture]
|
|
|
|
|
|
|
| +-----------------------+
+------------+ +------------+ |
| | Enlightenment Display | |
| | 3D UI | |
| | Server for Tizen +------------------>|
EvasGL | | Toolkit | |
| | | |
| | | |
| | |
+-----+------+ +-----+------+ |
| +--+-----------------+--+
| | |
| | |
v | |
| | |
+------------+ | |
| | | | GPU
Vendor | | |
| | | |
GL/EGL |<-----------+ |
| | | |
Driver | |
| | |
+-----+------+ |
| | |
| |
| v v
v |
| +-----------------------+ +----------------------+
+------------+ |
| | TDM | | TBM | |
| |
| |(Tizen Display Manager)+--->|(Tizen Buffer Manager)|<-----|
TPL-EGL | |
| | | | | |
| |
| +-----------------------+ +----------------------+
+------------+ |
|
|
+--------------------------------------------------------------------------------------------------+
< display server / wayland-egl client >
+-----------------------------+
+-------------------------------+
| | |
|
| +-----------------------+ | |
+-----------------------+ |
| | Enlightenment Display +-------+ |
| wayland-egl client | |
| | Server for Tizen | | | |
+--+-------------+------+ |
| +----------+------------+ | | |
| | |
| | | | |
| | |
| v | | |
| | |
| +-----------------------+ | | |
| | |
| | EVAS GL TBM | | | |
| | |
| +----+-------------+----+ | | |
| | |
| | | | | |
| | |
| | v | | |
v v |
| | +---------+ | | +--------------+ |
+-----+ +-------------+ |
| | | EGL +-------|--->| GPU Vendor
|<---------+ EGL | | wayland-egl | |
| | +----+----+ | | | GL Driver | |
+--+--+ +---+---------+ |
| | | | | +--------------+ |
| | ^ |
| v v | | |
v v | |
| +---------+ +---------+ | | +--------------+ |
+--------------------+--+ |
| | TBM |<--+ TPL-EGL +-------|--->| wayland-tbm
|<---------+ TPL-EGL | |
| +---------+ +---------+ | | +--------------+ |
+-----------------------+ |
| | | ^ |
|
| | | | |
|
+-----------------------------+ +------------+
+-------------------------------+
* TBM:
- Tizen Buffer Manager (TBM) provides the abstraction interface for
the graphic buffer manager
in Tizen. [1]
- Why does it needed?
Because different vendors provides different user-level interface
for the memory manager,
Tizen made TBM for supporting a common interface. refer [3], page 6-8.
* TDM:
- TDM stands for Tizen Display Manager. Tizen Display Manager (TDM)
provides the display device
abstraction interface for the display server to allow the direct
access to graphics hardware
in a safe and efficient manner as a display HAL. The primary goal
of TDM is the unification
of display hardware management procedures in user space. [2]
- Why does it needed?
Because different vendors provides different user-level interface
for the display devices,
Tizen made TDM for supporting a common interface. refer [3], page 15-16.
* wayland-tbm:
- wayland-tbm is a protocol for graphics memory management for Tizen.
The wayland-tbm provides the library for sharing the
tbm_surfaces between the client and the server.
When the client creates the wl_buffer though the wayland-tbm
library, the client can gets
the wl_buffer which is shared with the server through the wl_tbm protocol.
- wayland-tbm suppots two major features
1) sharing the tbm_surfaces between the client and the server
* it is similar with wayland-drm but it shares tbm_surface
as a base buffer.
2) obtaining the scanout buffer and assigning it to the server
or the client.
* Because some vendor provide limited scanout buffers,
therefore tizen added a protocol
of releasing/assigning scanoutbuffers.
* non-compisite mode / direct rendering: obtaining scanout
buffer from display-server and
assigning it to the
wayland-egl client.
* composite mode: obtaining the scanout buffer from the
wayland-egl client and assigning it
to the display-server.
* TPL-EGL:
- TPL-EGL is an abstraction layer for surface and buffer
management on Tizen platform aimed to
implement the EGL porting layer of OpenGLES driver over various
display protocols.
TPL-EGL treats tbm_surface as a base buffer object. And it uses
wayland-tbm protocol
instead of wayland-drm for sharing buffers on wayland-egl.
It supports tbm, wayland-egl, gbm window system.
And tizen's enligthenment display server create egl_display from
tbm instead of gbm. [4],[5]
Compared to mesa, Tizen Platform depends on TBM, TDM, wayland-tbm protocol.
Tizen uses TBM for treating a native buffer. And Display manager uses
tbm_surface as a base buffer for displying.
And for sharing native buffers between display server and wayland-egl
client tizen uses wayland-tbm protocol
also wayland-tbm protocol/library provides a manners of managing
limited scanout buffers between the client and the server.
Therefore to support Tizen to mesa egl, I am suggesting to add new
window system code for Tizen.
Thanks for reading this far, comments welcome.
Thanks,
Gwan-gyeong.
[1] https://wiki.tizen.org/TBM
[2] https://wiki.tizen.org/TDM
[3] Tizen Buffer HAL and Tizen Display HAL
https://www.tizenconference.com/frontend/site/show-details?eventId=2612&object=session&id=21124
https://swoogo.s3.amazonaws.com/uploads/46837-5926fd6b24dfd.pdf
[4]
https://www.x.org/wiki/Events/XDC2016/Program/XDC2016_Tizen_Window_System_EGL_Vulkan.pdf
[5] https://wiki.tizen.org/3.0_Porting_Guide/Graphics_and_UI
2017-10-28 2:22 GMT+09:00 Kenneth Graunke <kenn...@whitecape.org>:
> On Thursday, October 26, 2017 11:16:06 AM PDT Eric Anholt wrote:
>> Gwan-gyeong Mun <elong...@gmail.com> writes:
>>
>> > Hi,
>> >
>> > These Patch v5 series modified with new helper function series [1].
>> >
>> > These series only have mesa for tizen feature.
>> >
>> > [1] https://patchwork.freedesktop.org/series/32577/
>>
>> Rather than have another giant pile of window system code in the tree,
>> I'd like to see a serious discussion of why you aren't using the
>> existing wayland and gbm platforms and what you would need from them.
>> The TPL stuff looks like abstraction for the sake of abstraction, to me.
>
> I agree with Eric. I've never understood why this is necessary.
--
Gwan-gyeong Mun
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