[fbcon] Add generic concept of a frame buffer console

Add support for a simple frame buffer console, using single buffering
and a fixed-width bitmap font.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 160 insertions, 0 deletions

diff --git a/src/include/ipxe/fbcon.h b/src/include/ipxe/fbcon.h
new file mode 100644
index 000000000..913a7feaf
--- /dev/null
+++ b/src/include/ipxe/fbcon.h
@@ -0,0 +1,160 @@
+#ifndef _IPXE_FBCON_H
+#define _IPXE_FBCON_H
+
+/** @file
+ *
+ * Frame buffer console
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <ipxe/ansiesc.h>
+#include <ipxe/uaccess.h>
+
+struct pixel_buffer;
+
+/** Character width, in pixels */
+#define FBCON_CHAR_WIDTH 9
+
+/** Character height, in pixels */
+#define FBCON_CHAR_HEIGHT 16
+
+/** Bold colour modifier (RGB value) */
+#define FBCON_BOLD 0x555555
+
+/** Transparent background magic colour (raw colour value) */
+#define FBCON_TRANSPARENT 0xffffffff
+
+/** A font glyph */
+struct fbcon_font_glyph {
+	/** Row bitmask */
+	uint8_t bitmask[FBCON_CHAR_HEIGHT];
+} __attribute__ (( packed ));
+
+/** A font definition */
+struct fbcon_font {
+	/** Character glyphs */
+	userptr_t start;
+} __attribute__ (( packed ));
+
+/** A frame buffer geometry
+ *
+ * The geometry is defined in terms of "entities" (which can be either
+ * pixels or characters).
+ */
+struct fbcon_geometry {
+	/** Width (number of entities per displayed row) */
+	unsigned int width;
+	/** Height (number of entities per displayed column) */
+	unsigned int height;
+	/** Length of a single entity */
+	size_t len;
+	/** Stride (offset between vertically adjacent entities) */
+	size_t stride;
+};
+
+/** A frame buffer margin */
+struct fbcon_margin {
+	/** Left margin */
+	unsigned int left;
+	/** Right margin */
+	unsigned int right;
+	/** Top margin */
+	unsigned int top;
+	/** Bottom margin */
+	unsigned int bottom;
+};
+
+/** A frame buffer colour mapping */
+struct fbcon_colour_map {
+	/** Red scale (right shift amount from 24-bit RGB) */
+	uint8_t red_scale;
+	/** Green scale (right shift amount from 24-bit RGB) */
+	uint8_t green_scale;
+	/** Blue scale (right shift amount from 24-bit RGB) */
+	uint8_t blue_scale;
+	/** Red LSB */
+	uint8_t red_lsb;
+	/** Green LSB */
+	uint8_t green_lsb;
+	/** Blue LSB */
+	uint8_t blue_lsb;
+};
+
+/** A frame buffer text cell */
+struct fbcon_text_cell {
+	/** Foreground colour */
+	uint32_t foreground;
+	/** Background colour */
+	uint32_t background;
+	/** Character */
+	unsigned int character;
+};
+
+/** A frame buffer text array */
+struct fbcon_text {
+	/** Stored text cells */
+	userptr_t start;
+};
+
+/** A frame buffer background picture */
+struct fbcon_picture {
+	/** Start address */
+	userptr_t start;
+	/** Pixel geometry */
+	struct fbcon_geometry pixel;
+	/** Character geometry */
+	struct fbcon_geometry character;
+	/** Margin */
+	struct fbcon_margin margin;
+	/** Indent to first character (in bytes) */
+	size_t indent;
+};
+
+/** A frame buffer console */
+struct fbcon {
+	/** Start address */
+	userptr_t start;
+	/** Length of one complete displayed screen */
+	size_t len;
+	/** Pixel geometry */
+	struct fbcon_geometry *pixel;
+	/** Character geometry */
+	struct fbcon_geometry character;
+	/** Margin */
+	struct fbcon_margin margin;
+	/** Indent to first character (in bytes) */
+	size_t indent;
+	/** Colour mapping */
+	struct fbcon_colour_map *map;
+	/** Font definition */
+	struct fbcon_font *font;
+	/** Text foreground raw colour */
+	uint32_t foreground;
+	/** Text background raw colour */
+	uint32_t background;
+	/** Bold colour modifier raw colour */
+	uint32_t bold;
+	/** Text cursor X position */
+	unsigned int xpos;
+	/** Text cursor Y position */
+	unsigned int ypos;
+	/** ANSI escape sequence context */
+	struct ansiesc_context ctx;
+	/** Text array */
+	struct fbcon_text text;
+	/** Background picture */
+	struct fbcon_picture picture;
+};
+
+extern int fbcon_init ( struct fbcon *fbcon, userptr_t start,
+			struct fbcon_geometry *pixel,
+			struct fbcon_colour_map *map,
+			struct fbcon_font *font,
+			struct pixel_buffer *pixbuf );
+extern void fbcon_fini ( struct fbcon *fbcon );
+extern void fbcon_putchar ( struct fbcon *fbcon, int character );
+
+#endif /* _IPXE_FBCON_H */