Re: [PATCH] fbcon: make cursor display conditional

[Clemens Ladisch <clemens@ladisch.de>]

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@ladisch.de>

--- 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