Hi, Some people use 66-cells braille devices for reading the console, and hence would like to reduce the width of the screen by using:
stty cols 66 However, the vga text console doesn't behave correctly: the 14 first characters of the second line are put on the right of the first line and so forth. Here is a patch to correct that. It corrects the disp_end and offset registers of the vga board on console resize and console switch. On usual screens, you then correctly get a right and/or bottom blank margin. On some laptop panels, the output is resized so that text actually gets magnified, which can be great for some people (see http://dept-info.labri.fr/~thibault/ls.jpg ). Regards, Samuel Signed-off-by: Samuel Thibault <[EMAIL PROTECTED]> --- linux-2.6.13/drivers/video/console/vgacon.c 2005-09-02 18:18:38.000000000 +0200 +++ linux/drivers/video/console/vgacon.c 2005-09-03 01:18:05.000000000 +0200 @@ -497,6 +497,56 @@ static void vgacon_cursor(struct vc_data } } +static int vgacon_doresize(struct vc_data *c, + unsigned int width, unsigned int height) { + unsigned long flags; + unsigned int scanlines = height * c->vc_font.height; + u8 scanlines_lo, r7, vsync_end, mode; + + spin_lock_irqsave(&vga_lock, flags); + + outb_p(VGA_CRTC_MODE, vga_video_port_reg); + mode = inb_p(vga_video_port_val); + + if (mode & 0x04) + scanlines >>= 1; + + scanlines -= 1; + scanlines_lo = scanlines & 0xff; + + outb_p(VGA_CRTC_OVERFLOW, vga_video_port_reg); + r7 = inb_p(vga_video_port_val) & ~0x42; + + if (scanlines & 0x100) + r7 |= 0x02; + if (scanlines & 0x200) + r7 |= 0x40; + + /* deprotect registers */ + outb_p(VGA_CRTC_V_SYNC_END, vga_video_port_reg); + vsync_end = inb_p(vga_video_port_val); + outb_p(VGA_CRTC_V_SYNC_END, vga_video_port_reg); + outb_p(vsync_end & ~0x80, vga_video_port_val); + + outb_p(VGA_CRTC_H_DISP, vga_video_port_reg); + outb_p(width - 1, vga_video_port_val); + outb_p(VGA_CRTC_OFFSET, vga_video_port_reg); + outb_p(width >> 1, vga_video_port_val); + + outb_p(VGA_CRTC_V_DISP_END, vga_video_port_reg); + outb_p(scanlines_lo, vga_video_port_val); + outb_p(VGA_CRTC_OVERFLOW, vga_video_port_reg); + outb_p(r7,vga_video_port_val); + + /* reprotect registers */ + outb_p(VGA_CRTC_V_SYNC_END, vga_video_port_reg); + outb_p(vsync_end, vga_video_port_val); + + spin_unlock_irqrestore(&vga_lock, flags); + + return 0; +} + static int vgacon_switch(struct vc_data *c) { /* @@ -510,9 +560,12 @@ static int vgacon_switch(struct vc_data /* We can only copy out the size of the video buffer here, * otherwise we get into VGA BIOS */ - if (!vga_is_gfx) + if (!vga_is_gfx) { scr_memcpyw((u16 *) c->vc_origin, (u16 *) c->vc_screenbuf, c->vc_screenbuf_size > vga_vram_size ? vga_vram_size : c->vc_screenbuf_size); + vgacon_doresize(c, c->vc_cols, c->vc_rows); + } + return 0; /* Redrawing not needed */ } @@ -962,6 +1015,15 @@ static int vgacon_font_get(struct vc_dat #endif +static int vgacon_resize(struct vc_data *c, unsigned int width, unsigned int height) { + if (width % 2 || width > ORIG_VIDEO_COLS || height > ORIG_VIDEO_LINES) + return -EINVAL; + + if (CON_IS_VISIBLE(c) && !vga_is_gfx) /* who knows */ + vgacon_doresize(c, width, height); + return 0; +} + static int vgacon_scrolldelta(struct vc_data *c, int lines) { if (!lines) /* Turn scrollback off */ @@ -1103,6 +1165,7 @@ const struct consw vga_con = { .con_blank = vgacon_blank, .con_font_set = vgacon_font_set, .con_font_get = vgacon_font_get, + .con_resize = vgacon_resize, .con_set_palette = vgacon_set_palette, .con_scrolldelta = vgacon_scrolldelta, .con_set_origin = vgacon_set_origin, - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
