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/******************************************************************************
* lfb.c
*
* linear frame buffer handling.
*/
#include <xen/config.h>
#include <xen/kernel.h>
#include <xen/lib.h>
#include <xen/errno.h>
#include "lfb.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
struct lfb_status {
struct lfb_prop lfbp;
unsigned char *lbuf, *text_buf;
unsigned int *line_len;
unsigned int xpos, ypos;
};
static struct lfb_status lfb;
static void lfb_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 = (lfb.lfbp.bits_per_pixel + 7) >> 3;
for ( i = 0; i < lfb.lfbp.font->height; i++ )
{
unsigned char *ptr = lfb.lbuf;
for ( j = 0; j < nr_chars; j++ )
{
const unsigned char *bits = lfb.lfbp.font->data;
bits += ((text_line[j] * lfb.lfbp.font->height + i) *
((lfb.lfbp.font->width + 7) >> 3));
for ( b = lfb.lfbp.font->width; b--; )
{
pixel = (*bits & (1u<<b)) ? lfb.lfbp.pixel_on : 0;
memcpy(ptr, &pixel, bpp);
ptr += bpp;
}
}
memset(ptr, 0, (lfb.lfbp.width - nr_chars * lfb.lfbp.font->width) * bpp);
memcpy(video_line, lfb.lbuf, nr_cells * lfb.lfbp.font->width * bpp);
video_line += lfb.lfbp.bytes_per_line;
}
}
/* Fast mode which redraws all modified parts of a 2D text buffer. */
void lfb_redraw_puts(const char *s)
{
unsigned int i, min_redraw_y = lfb.ypos;
char c;
/* Paste characters into text buffer. */
while ( (c = *s++) != '\0' )
{
if ( (c == '\n') || (lfb.xpos >= lfb.lfbp.text_columns) )
{
if ( ++lfb.ypos >= lfb.lfbp.text_rows )
{
min_redraw_y = 0;
lfb.ypos = lfb.lfbp.text_rows - 1;
memmove(lfb.text_buf, lfb.text_buf + lfb.lfbp.text_columns,
lfb.ypos * lfb.lfbp.text_columns);
memset(lfb.text_buf + lfb.ypos * lfb.lfbp.text_columns, 0, lfb.xpos);
}
lfb.xpos = 0;
}
if ( c != '\n' )
lfb.text_buf[lfb.xpos++ + lfb.ypos * lfb.lfbp.text_columns] = c;
}
/* Render modified section of text buffer to VESA linear framebuffer. */
for ( i = min_redraw_y; i <= lfb.ypos; i++ )
{
const unsigned char *line = lfb.text_buf + i * lfb.lfbp.text_columns;
unsigned int width;
for ( width = lfb.lfbp.text_columns; width; --width )
if ( line[width - 1] )
break;
lfb_show_line(line,
lfb.lfbp.lfb + i * lfb.lfbp.font->height * lfb.lfbp.bytes_per_line,
width, max(lfb.line_len[i], width));
lfb.line_len[i] = width;
}
lfb.lfbp.flush();
}
/* Slower line-based scroll mode which interacts better with dom0. */
void lfb_scroll_puts(const char *s)
{
unsigned int i;
char c;
while ( (c = *s++) != '\0' )
{
if ( (c == '\n') || (lfb.xpos >= lfb.lfbp.text_columns) )
{
unsigned int bytes = (lfb.lfbp.width *
((lfb.lfbp.bits_per_pixel + 7) >> 3));
unsigned char *src = lfb.lfbp.lfb + lfb.lfbp.font->height * lfb.lfbp.bytes_per_line;
unsigned char *dst = lfb.lfbp.lfb;
/* New line: scroll all previous rows up one line. */
for ( i = lfb.lfbp.font->height; i < lfb.lfbp.height; i++ )
{
memcpy(dst, src, bytes);
src += lfb.lfbp.bytes_per_line;
dst += lfb.lfbp.bytes_per_line;
}
/* Render new line. */
lfb_show_line(
lfb.text_buf,
lfb.lfbp.lfb + (lfb.lfbp.text_rows-1) * lfb.lfbp.font->height *
lfb.lfbp.bytes_per_line,
lfb.xpos, lfb.lfbp.text_columns);
lfb.xpos = 0;
}
if ( c != '\n' )
lfb.text_buf[lfb.xpos++] = c;
}
lfb.lfbp.flush();
}
void lfb_carriage_return(void)
{
lfb.xpos = 0;
}
int __init lfb_init(struct lfb_prop *lfbp)
{
if ( lfbp->width > MAX_XRES || lfbp->height > MAX_YRES )
{
printk(XENLOG_WARNING "Couldn't initialize a %ux%u framebuffer early.\n",
lfbp->width, lfbp->height);
return -EINVAL;
}
lfb.lfbp = *lfbp;
lfb.lbuf = xmalloc_bytes(lfb.lfbp.bytes_per_line);
lfb.text_buf = xzalloc_bytes(lfb.lfbp.text_columns * lfb.lfbp.text_rows);
lfb.line_len = xzalloc_array(unsigned int, lfb.lfbp.text_columns);
if ( !lfb.lbuf || !lfb.text_buf || !lfb.line_len )
goto fail;
return 0;
fail:
printk(XENLOG_ERR "Couldn't allocate enough memory to drive the framebuffer\n");
lfb_free();
return -ENOMEM;
}
void lfb_free(void)
{
xfree(lfb.lbuf);
xfree(lfb.text_buf);
xfree(lfb.line_len);
}
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