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Share RAM resource help
- From: Oscar <martinos72 at libero dot it>
- To: Ecos-Discuss <ecos-discuss at sources dot redhat dot com>
- Date: Sun, 04 Apr 2004 17:17:05 +0100
- Subject: [ECOS] Share RAM resource help
I'm working with ecos+microwindows on xscale PXA255 and i need:
1. improve built in LCD controller (i need to drive lcd bigger then
640x480) adding external logic for manage the frame buffer refresh
outside from the cpu's databus to avoid bus overhead
2. add an external video source that it'll share the LCD with ECOS.
So i need to share the RAM frame buffer beetween CPU (microwindows
thread), hardware LCD refresh (hardware1 thread that only needs to read
from the fb) and second external video source (hardware2 thread that
only needs to write to the fb): i've one sw thread and two hw threads.
The hardware threads always need to finish the own execution before
being interrupt.
To resolve this problem i thought to manage the hw threads by sw threads
give to ecos the necessary input/output signal for manage the hw (ex.
request_resource_from_hw and hw_finish_thread_execution) and use ECOS
mutex facilietes for manage the RAM sharing.
Could be this a good way to face the problem? Have anyone another idea
or recommendation?
I can't understand where is the best point in MW source code to put the
CYG_MUTEX_LOCK, i think just before the frame buffer call.... but where?
In wich file?
Thanks
OSCAR
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