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>
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>
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>
eric.gao@rock-chips.com
Simon Glass