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A bit of cleanup in vga functions

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This commit is contained in:
Thomas Lovén 2017-12-14 23:49:46 +01:00
parent 15bbfd6e6a
commit e6d046d593
1 changed files with 10 additions and 13 deletions
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23
src/kernel/drivers/vga.c
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@ -16,9 +16,10 @@ uint8_t format;
void vga_init()
{
vidmem = VGA_MEMORY;
memset(vidmem, 0, VGA_SIZE*2);
memset(vidmem, 0, VGA_SIZE*sizeof(struct vga_cell));
format = 0x7;
// White text on black background
format = 0x07;
}
void movecursor()
@ -38,14 +39,12 @@ void scroll()
{
while(cursor >= VGA_SIZE)
{
for(int i = 0; i < VGA_ROWS-1; i++)
for(int j = 0; j < VGA_COLS; j++)
buffer[VGA_POS(i, j)] = buffer[VGA_POS(i+1, j)];
for(int i = 0; i < VGA_COLS; i++)
buffer[VGA_POS(VGA_ROWS-1, i)] = (struct vga_cell){.c='\0', .f=format};
cursor -= VGA_COLS;
// Move everything up one row
memmove(buffer, &buffer[VGA_POS(1,0)], VGA_COLS*(VGA_ROWS-1)*sizeof(struct vga_cell));
// Clear last row
memset(&buffer[VGA_POS(VGA_ROWS-1, 0)], 0, VGA_COLS*sizeof(struct vga_cell));
cursor -= VGA_COLS;
}
}
void vga_write(char c)
@ -53,12 +52,10 @@ void vga_write(char c)
switch(c)
{
case '\n':
cursor += VGA_COLS;
cursor -= VGA_COL(cursor);
cursor += VGA_COLS - VGA_COL(cursor);
break;
default:
buffer[cursor] = (struct vga_cell){.c = c, .f=format};
cursor++;
buffer[cursor++] = (struct vga_cell){.c = c, .f=format};
}
scroll();
flush();