Commit graph

3 commits

Author SHA1 Message Date
eric.gao@rock-chips.com
7682736c89 video: Fix crash when scroll screen
After enabling log printing to lcd, when the screen starts
scrolling, system crashes. Log is shown as bellow:

    "Synchronous Abort" handler, esr 0x96000045
    "Synchronous Abort" handler, esr 0x96000045

Checking the source code, we found that the variable "pixels"
gets a wrong value:

    int pixels = VIDEO_FONT_HEIGHT * vid_priv->line_length;

"pixels" here means the value of pixels for a character, rather
than the bytes for a character. So the variable "pixels" is 4
times bigger than it's exact value, which will cause the memory
overflow when the cpu runs the following code:

    for (i = 0; i < pixels; i++)
        *dst++ = clr; <<----

Signed-off-by: Eric Gao <eric.gao@rock-chips.com>
2017-04-14 16:11:38 +02:00
Simon Glass
f266178698 video: Use fractional units for X coordinates
With anti-aliased fonts we need a more fine-grained horizontal position
than a single pixel. Characters can be positioned to start part-way through
a pixel, with anti-aliasing (greyscale edges) taking care of the visual
effect.

To cope with this, use fractional units (1/256 pixel) for horizontal
positions in the text console.

Signed-off-by: Simon Glass <sjg@chromium.org>
[agust: rebased]
Signed-off-by: Anatolij Gustschin <agust@denx.de>
2016-01-30 10:53:26 +01:00
Simon Glass
72cded9ec0 dm: video: Add a 'normal' text console driver
Most of the time we don't need to rotate the display so a simple font
blitting feature is enough for our purposes. Add a simple driver which
supports this function. It provides text output on the console using
the standard 8x16-pixel font.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Anatolij Gustschin <agust@denx.de>
2016-01-20 19:10:15 -07:00