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From: Alessio Sangalli <alesan@manoweb.com>
To: "linux-fbdev-devel@lists.sourceforge.net"
	<linux-fbdev-devel@lists.sourceforge.net>
Subject: Framebuffer using system memory
Date: Fri, 24 Apr 2009 18:13:52 -0700	[thread overview]
Message-ID: <49F263D0.4030108@manoweb.com> (raw)

Hi I am working on a framebuffer that uses the system memory.

What I mean here is that I need to pass mem=120M to a system that has
128MB to "reserve" 8MB of memory for the framebuffer; then I program the
hardware to use that region of memory.

The reason I do this is that it seems impossible to kmalloc more that
4MB of contiguos physical memory with the Linux Kernel.

Bottom line, I do not know how to map those 8MB back to userspace. If
userspace opens mmaps /dev/mem and writes to the appropriate location it
can access the fb perfectly.

Any hints? All of this is on ARM9.

Thank you
Alessio


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             reply	other threads:[~2009-04-25  1:26 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-25  1:13 Alessio Sangalli [this message]
2009-04-25  7:45 ` Framebuffer using system memory Geert Uytterhoeven
2009-04-25  9:37   ` Alessio Sangalli
2009-04-25 19:08   ` Alessio Sangalli
2009-04-26 18:03     ` Geert Uytterhoeven

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