nanogui: 4bpp OK, 1bpp Not So Good
Subject:
4bpp OK, 1bpp Not So Good
From:
Gil Glass ####@####.####
Date:
23 Jan 2006 20:29:14 +0000
Message-Id: <OF892F5232.4B812234-ON852570FF.006FB356-852570FF.007087A7@acterna.com>
Hello,
I have been using Nano-X version 0.91 compiled for an ARM processor
successfully for some time now. I've been using it in framebuffer mode
with a 4 bit-per-pixel monochrome display and it's been just fine.
However, the real-deal hardware that my product is going to use is one
bit-per-pixel and, wouldn't you know it, the display hardware expects 4
pixels in each data word sent to it!
Now we have modified the Linux framebuffer primitives to correctly handle
the 4-pixel-nybble structure (2.6.11 does it wrong) and we can write to
the display via /dev/tty0. However, when I try to run Nano-X, as it is
currently built, on the 1-bpp display, I see the expected image but with
narrow vertical stripes across the entire display. It's hard to tell, but
the stripes are probably about 4 pixels wide. Any idea what's up? Does
Nano-X use the Linux framebuffer primitives, i.e. those for drawing
rectangles, etc., or does Nano-X draw directly to framebuffer space? If
this is the case, are we looking at modifying Nano-X?
Finally, I'm currently using SCREEN_PIXTYPE = MWPF_PALETTE in my config
file. Is this correct?
Cheers,
Gil Glass
Telecom Field Services
JDSU
Germantown, MD, USA
+1-240-404-2551
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