Re: [PATCH] fbcon: make cursor display conditional

From: Clemens Ladisch
Date: Mon Nov 09 2009 - 03:35:18 EST


Daniel Mack wrote:
> > On Fri, Nov 06, 2009 at 09:16:44AM +0100, Clemens Ladisch wrote:
> > > Wouldn't it be more useful to change the CUR_DEFAULT symbol (see the
> > > end of <linux/console_struct.h>) into a kernel parameter, instead of
> > > adding a new flag?
>
> Ok, much better idea, I agree. See the patch below.
>
> Subject: [PATCH] char/console: make default cursor type configurable
>
> --- a/drivers/char/vt.c
> +++ b/drivers/char/vt.c
> +#if defined(CONFIG_CONSOLE_DEF_CUR_NONE)
> +#define CUR_DEFAULT CUR_NONE
> +
> +#elif defined(CONFIG_CONSOLE_DEF_CUR_UNDERLINE)
> +#define CUR_DEFAULT CUR_UNDERLINE
> +...

With a separate Kconfig variable, we can avoid having to put the
parallel list into vt.c.

Furthermore, we can add options for the software cursor while we're
at it; something like this:

Signed-off-by: Clemens Ladisch <clemens@xxxxxxxxxx>

--- linux-2.6/include/linux/console_struct.h
+++ linux-2.6/include/linux/console_struct.h
@@ -130,8 +130,6 @@ extern void vc_SAK(struct work_struct *w
#define CUR_HWMASK 0x0f
#define CUR_SWMASK 0xfff0

-#define CUR_DEFAULT CUR_UNDERLINE
-
#define CON_IS_VISIBLE(conp) (*conp->vc_display_fg == conp)

#endif /* _LINUX_CONSOLE_STRUCT_H */
--- linux-2.6/drivers/char/vt.c
+++ linux-2.6/drivers/char/vt.c
@@ -138,6 +138,11 @@ const struct consw *conswitchp;
#define DEFAULT_BELL_PITCH 750
#define DEFAULT_BELL_DURATION (HZ/8)

+#define CUR_DEFAULT (CONFIG_CUR_DEFAULT_HW | \
+ CONFIG_CUR_DEFAULT_SW_FLAGS | \
+ (CONFIG_CUR_DEFAULT_SW_ATTR_XOR << 8) | \
+ (CONFIG_CUR_DEFAULT_SW_ATTR_SET << 16))
+
struct vc vc_cons [MAX_NR_CONSOLES];

#ifndef VT_SINGLE_DRIVER
--- linux-2.6/drivers/char/Kconfig
+++ linux-2.6/drivers/char/Kconfig
@@ -88,6 +88,104 @@ config VT_HW_CONSOLE_BINDING
information. For framebuffer console users, please refer to
<file:Documentation/fb/fbcon.txt>.

+choice
+ prompt "Default hardware cursor shape"
+ depends on HW_CONSOLE
+ default CUR_DEFAULT_UNDERLINE
+ help
+ Select the default shape of the blinking hardware cursor.
+
+ config CUR_DEFAULT_DEF
+ bool "Default"
+ config CUR_DEFAULT_NONE
+ bool "None"
+ config CUR_DEFAULT_UNDERLINE
+ bool "Underline"
+ config CUR_DEFAULT_LOWER_THIRD
+ bool "Lower third"
+ config CUR_DEFAULT_LOWER_HALF
+ bool "Lower half"
+ config CUR_DEFAULT_TWO_THIRDS
+ bool "Two thirds"
+ config CUR_DEFAULT_BLOCK
+ bool "Block"
+endchoice
+
+config CUR_DEFAULT_HW
+ depends on HW_CONSOLE
+ int
+ default 0 if CUR_DEFAULT_DEF
+ default 1 if CUR_DEFAULT_NONE
+ default 2 if CUR_DEFAULT_UNDERLINE
+ default 3 if CUR_DEFAULT_LOWER_THIRD
+ default 4 if CUR_DEFAULT_LOWER_HALF
+ default 5 if CUR_DEFAULT_TWO_THIRDS
+ default 6 if CUR_DEFAULT_BLOCK
+
+config CUR_DEFAULT_SW
+ bool "Use software cursor by default"
+ depends on HW_CONSOLE
+ default n
+ help
+ The software cursor allows you to customize the appearance of the
+ cursor; this is done by changing the attributes (the color) of the
+ character under the cursor.
+
+ See <file:Documentation/VGA-softcursor.txt> for more information.
+
+config CUR_DEFAULT_SW_ATTR_XOR
+ depends on HW_CONSOLE
+ prompt "Software cursor changed attribute bits" if CUR_DEFAULT_SW
+ int
+ range 0 255
+ default 0
+ help
+ Enter the character attribute bits that are changed by the
+ software cursor. This is equivalent to the second parameter
+ of the <ESC>[?1;2;3c escape sequence; for more information,
+ see <file:Documentation/VGA-softcursor.txt>.
+
+config CUR_DEFAULT_SW_ATTR_SET
+ depends on HW_CONSOLE
+ prompt "Software cursor set attribute bits" if CUR_DEFAULT_SW
+ int
+ range 0 255
+ default 0
+ help
+ Enter the character attribute bits that are set by the
+ software cursor. This is equivalent to the third parameter
+ of the <ESC>[?1;2;3c escape sequence; for more information,
+ see <file:Documentation/VGA-softcursor.txt>.
+
+config CUR_DEFAULT_SW_CHANGE_BKGND
+ bool "Software cursor always changes background"
+ depends on CUR_DEFAULT_SW
+ default y
+ help
+ If you say Y here, the software cursor will ensure that the
+ background color of the character under the cursor is changed,
+ even if the cursor color is the same as the original character's
+ color.
+
+config CUR_DEFAULT_SW_BKGND_DIFFERENT
+ bool "Software cursor makes foreground color different from background"
+ depends on CUR_DEFAULT_SW
+ default y
+ help
+ If you say Y here, the software cursor will ensure that the
+ foreground color of the character under the cursor is different
+ from the background color.
+
+config CUR_DEFAULT_SW_FLAGS
+ depends on HW_CONSOLE
+ int
+ default 0 if !CUR_DEFAULT_SW
+ # 16 + (32 if CHANGE_BKGND) + (64 if BKGND_DIFFERENT):
+ default 16 if !CUR_DEFAULT_SW_CHANGE_BKGND && !CUR_DEFAULT_SW_BKGND_DIFFERENT
+ default 48 if CUR_DEFAULT_SW_CHANGE_BKGND && !CUR_DEFAULT_SW_BKGND_DIFFERENT
+ default 80 if !CUR_DEFAULT_SW_CHANGE_BKGND && CUR_DEFAULT_SW_BKGND_DIFFERENT
+ default 112 if CUR_DEFAULT_SW_CHANGE_BKGND && CUR_DEFAULT_SW_BKGND_DIFFERENT
+
config DEVKMEM
bool "/dev/kmem virtual device support"
default y
--
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