Mailing List Archive

Abstract away from vesa.c the funcions to handle a linear framebuffer
and print characters to it.
The corresponding functions are going to be removed from vesa.c in the
next patch.

Changes in v3:
- rename fb_cr to fb_carriage_return.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
xen/drivers/video/Makefile | 1 +
xen/drivers/video/fb.c | 209 ++++++++++++++++++++++++++++++++++++++++++++
xen/drivers/video/fb.h | 49 ++++++++++
3 files changed, 259 insertions(+), 0 deletions(-)
create mode 100644 xen/drivers/video/fb.c
create mode 100644 xen/drivers/video/fb.h

diff --git a/xen/drivers/video/Makefile b/xen/drivers/video/Makefile
index 2993c39..3b3eb43 100644
--- a/xen/drivers/video/Makefile
+++ b/xen/drivers/video/Makefile
@@ -2,4 +2,5 @@ obj-$(HAS_VGA) := vga.o
obj-$(HAS_VIDEO) += font_8x14.o
obj-$(HAS_VIDEO) += font_8x16.o
obj-$(HAS_VIDEO) += font_8x8.o
+obj-$(HAS_VIDEO) += fb.o
obj-$(HAS_VGA) += vesa.o
diff --git a/xen/drivers/video/fb.c b/xen/drivers/video/fb.c
new file mode 100644
index 0000000..a4f0500
--- /dev/null
+++ b/xen/drivers/video/fb.c
@@ -0,0 +1,209 @@
+/******************************************************************************
+ * fb.c
+ *
+ * linear frame buffer handling.
+ */
+
+#include <xen/config.h>
+#include <xen/kernel.h>
+#include <xen/lib.h>
+#include <xen/errno.h>
+#include "fb.h"
+#include "font.h"
+
+#define MAX_XRES 1900
+#define MAX_YRES 1200
+#define MAX_BPP 4
+#define MAX_FONT_W 8
+#define MAX_FONT_H 16
+static __initdata unsigned int line_len[MAX_XRES / MAX_FONT_W];
+static __initdata unsigned char lbuf[MAX_XRES * MAX_BPP];
+static __initdata unsigned char text_buf[(MAX_XRES / MAX_FONT_W) * \
+ (MAX_YRES / MAX_FONT_H)];
+
+struct fb_status {
+ struct fb_prop fbp;
+
+ unsigned char *lbuf, *text_buf;
+ unsigned int *line_len;
+ unsigned int xpos, ypos;
+};
+static struct fb_status fb;
+
+static void fb_show_line(
+ const unsigned char *text_line,
+ unsigned char *video_line,
+ unsigned int nr_chars,
+ unsigned int nr_cells)
+{
+ unsigned int i, j, b, bpp, pixel;
+
+ bpp = (fb.fbp.bits_per_pixel + 7) >> 3;
+
+ for ( i = 0; i < fb.fbp.font->height; i++ )
+ {
+ unsigned char *ptr = fb.lbuf;
+
+ for ( j = 0; j < nr_chars; j++ )
+ {
+ const unsigned char *bits = fb.fbp.font->data;
+ bits += ((text_line[j] * fb.fbp.font->height + i) *
+ ((fb.fbp.font->width + 7) >> 3));
+ for ( b = fb.fbp.font->width; b--; )
+ {
+ pixel = (*bits & (1u<<b)) ? fb.fbp.pixel_on : 0;
+ memcpy(ptr, &pixel, bpp);
+ ptr += bpp;
+ }
+ }
+
+ memset(ptr, 0, (fb.fbp.width - nr_chars * fb.fbp.font->width) * bpp);
+ memcpy(video_line, fb.lbuf, nr_cells * fb.fbp.font->width * bpp);
+ video_line += fb.fbp.bytes_per_line;
+ }
+}
+
+/* Fast mode which redraws all modified parts of a 2D text buffer. */
+void fb_redraw_puts(const char *s)
+{
+ unsigned int i, min_redraw_y = fb.ypos;
+ char c;
+
+ /* Paste characters into text buffer. */
+ while ( (c = *s++) != '\0' )
+ {
+ if ( (c == '\n') || (fb.xpos >= fb.fbp.text_columns) )
+ {
+ if ( ++fb.ypos >= fb.fbp.text_rows )
+ {
+ min_redraw_y = 0;
+ fb.ypos = fb.fbp.text_rows - 1;
+ memmove(fb.text_buf, fb.text_buf + fb.fbp.text_columns,
+ fb.ypos * fb.fbp.text_columns);
+ memset(fb.text_buf + fb.ypos * fb.fbp.text_columns, 0, fb.xpos);
+ }
+ fb.xpos = 0;
+ }
+
+ if ( c != '\n' )
+ fb.text_buf[fb.xpos++ + fb.ypos * fb.fbp.text_columns] = c;
+ }
+
+ /* Render modified section of text buffer to VESA linear framebuffer. */
+ for ( i = min_redraw_y; i <= fb.ypos; i++ )
+ {
+ const unsigned char *line = fb.text_buf + i * fb.fbp.text_columns;
+ unsigned int width;
+
+ for ( width = fb.fbp.text_columns; width; --width )
+ if ( line[width - 1] )
+ break;
+ fb_show_line(line,
+ fb.fbp.lfb + i * fb.fbp.font->height * fb.fbp.bytes_per_line,
+ width, max(fb.line_len[i], width));
+ fb.line_len[i] = width;
+ }
+
+ fb.fbp.flush();
+}
+
+/* Slower line-based scroll mode which interacts better with dom0. */
+void fb_scroll_puts(const char *s)
+{
+ unsigned int i;
+ char c;
+
+ while ( (c = *s++) != '\0' )
+ {
+ if ( (c == '\n') || (fb.xpos >= fb.fbp.text_columns) )
+ {
+ unsigned int bytes = (fb.fbp.width *
+ ((fb.fbp.bits_per_pixel + 7) >> 3));
+ unsigned char *src = fb.fbp.lfb + fb.fbp.font->height * fb.fbp.bytes_per_line;
+ unsigned char *dst = fb.fbp.lfb;
+
+ /* New line: scroll all previous rows up one line. */
+ for ( i = fb.fbp.font->height; i < fb.fbp.height; i++ )
+ {
+ memcpy(dst, src, bytes);
+ src += fb.fbp.bytes_per_line;
+ dst += fb.fbp.bytes_per_line;
+ }
+
+ /* Render new line. */
+ fb_show_line(
+ fb.text_buf,
+ fb.fbp.lfb + (fb.fbp.text_rows-1) * fb.fbp.font->height * fb.fbp.bytes_per_line,
+ fb.xpos, fb.fbp.text_columns);
+
+ fb.xpos = 0;
+ }
+
+ if ( c != '\n' )
+ fb.text_buf[fb.xpos++] = c;
+ }
+
+ fb.fbp.flush();
+}
+
+void fb_carriage_return(void)
+{
+ fb.xpos = 0;
+}
+
+int __init fb_init(struct fb_prop fbp)
+{
+ if ( fbp.width > MAX_XRES || fbp.height > MAX_YRES )
+ {
+ printk("Couldn't initialize a %xx%x framebuffer early.\n",
+ fbp.width, fbp.height);
+ return -EINVAL;
+ }
+
+ fb.fbp = fbp;
+ fb.lbuf = lbuf;
+ fb.text_buf = text_buf;
+ fb.line_len = line_len;
+ return 0;
+}
+
+int __init fb_alloc(void)
+{
+ fb.lbuf = NULL;
+ fb.text_buf = NULL;
+ fb.line_len = NULL;
+
+ fb.lbuf = xmalloc_bytes(fb.fbp.bytes_per_line);
+ if ( !fb.lbuf )
+ goto fail;
+
+ fb.text_buf = xzalloc_bytes(fb.fbp.text_columns * fb.fbp.text_rows);
+ if ( !fb.text_buf )
+ goto fail;
+
+ fb.line_len = xzalloc_array(unsigned int, fb.fbp.text_columns);
+ if ( !fb.line_len )
+ goto fail;
+
+ memcpy(fb.lbuf, lbuf, fb.fbp.bytes_per_line);
+ memcpy(fb.text_buf, text_buf, fb.fbp.text_columns * fb.fbp.text_rows);
+ memcpy(fb.line_len, line_len, fb.fbp.text_columns);
+
+ return 0;
+
+fail:
+ printk(XENLOG_ERR "Couldn't allocate enough memory to drive "
+ "the framebuffer\n");
+ xfree(fb.lbuf);
+ xfree(fb.text_buf);
+ xfree(fb.line_len);
+
+ return -ENOMEM;
+}
+
+void fb_free(void)
+{
+ xfree(fb.lbuf);
+ xfree(fb.text_buf);
+ xfree(fb.line_len);
+}
diff --git a/xen/drivers/video/fb.h b/xen/drivers/video/fb.h
new file mode 100644
index 0000000..0084ffa
--- /dev/null
+++ b/xen/drivers/video/fb.h
@@ -0,0 +1,49 @@
+/*
+ * xen/drivers/video/fb.h
+ *
+ * Cross-platform framebuffer library
+ *
+ * Stefano Stabellini <stefano.stabellini@eu.citrix.com>
+ * Copyright (c) 2012 Citrix Systems.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _XEN_FB_H
+#define _XEN_FB_H
+
+#include <xen/init.h>
+
+struct fb_prop {
+ const struct font_desc *font;
+ unsigned char *lfb;
+ unsigned int pixel_on;
+ uint16_t width, height;
+ uint16_t bytes_per_line;
+ uint16_t bits_per_pixel;
+ void (*flush)(void);
+
+ unsigned int text_columns;
+ unsigned int text_rows;
+};
+
+void fb_redraw_puts(const char *s);
+void fb_scroll_puts(const char *s);
+void fb_carriage_return(void);
+void fb_free(void);
+
+/* initialize the framebuffer, can be called early (before xmalloc is
+ * available) */
+int __init fb_init(struct fb_prop fbp);
+/* fb_alloc allocates internal structures using xmalloc */
+int __init fb_alloc(void);
+
+#endif
--
1.7.2.5


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