fb: introduce flush for virtual framebuffer ...

Some drivers need an explicit sync method to flush the virtual
framebuffer to the display. It is called fb_flush().

fb_flush() gets called on fbc_putc, on fb_close and in the pattern cycle
in the fbtest command.

Signed-off-by: Bastian Stender <bst@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

console: replace set_active by open/close ...

Opening and closing consoles should be independent from setting them
active. This way it is possible to open e.g. a framebuffer console and
display text on it without showing stdout/stderr.

Signed-off-by: Bastian Stender <bst@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fbconsole: implement vt100 cursor shown/hidden ...

This implements the vt100 show cursor command '[?25h' and the hide
cursor command '[?25l'. It is useful for displaying text on a non-active
(no stdout/stdin/stderr) console with 'echo'.

Signed-off-by: Bastian Stender <bst@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fbconsole: check cursor position before moving ...

Moving the cursor to x=2, y=2 with "\e[3;3H" on a 12x2 framebuffer
console lead to a barebox crash while drawing the cursor. If the
cursor position is out of bounds clip the cursor to the corresponding
edge.

Signed-off-by: Bastian Stender <bst@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

font: fbconsole: add custom font supports ...

Signed-off-by: Du Huanpeng <u74147@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fbconsole: move font variable into struct font_desc ...

replace font related variables with a struct pointer,
font_desc.

Signed-off-by: Du Huanpeng <u74147@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fbconsole: no need to copy extra line ...

Signed-off-by: Aleksey Kuleshov <rndfax@yandex.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fb: fbconsole: Add missing blits ...

When using offscreen rendering we need some more points where we
blit the offscreen buffer to the screen. Add them.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fb: fbconsole: print cursor after clearing the screen ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

gui: Use fb provided shadowfb for offscreen rendering ...

The fb core now has builtin support for offscreen rendering, use
this and drop offscreen handling in the gui code.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

video: fbconsole: do not enter when we are already in fbconsole ...

Make it possible to issue console messages from inside the fbconsole
code without entering the fbconsole again.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

video: implement framebuffer console ...

This patch realizes framebuffer console support for barebox. It
supports colors and enough escape sequences to show the barebox
console and editor properly.

fbconsole mini-HOWTO
====================

1. compile sandbox barebox with

    CONFIG_VIDEO=y
    CONFIG_FRAMEBUFFER_CONSOLE=y
    CONFIG_DRIVER_VIDEO_SDL=y

2. run barebox

3. test fbconsole

    fbconsole0.active=oe

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>