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-rw-r--r--drivers/video/console/Kconfig24
-rw-r--r--drivers/video/console/vgacon.c244
2 files changed, 225 insertions, 43 deletions
diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig
index 6ee4498..4444bef 100644
--- a/drivers/video/console/Kconfig
+++ b/drivers/video/console/Kconfig
@@ -26,6 +26,30 @@ config VGA_CONSOLE
# fi
# fi
+config VGACON_SOFT_SCROLLBACK
+ bool "Enable Scrollback Buffer in System RAM"
+ depends on VGA_CONSOLE
+ default n
+ help
+ The scrollback buffer of the standard VGA console is located in
+ the VGA RAM. The size of this RAM is fixed and is quite small.
+ If you require a larger scrollback buffer, this can be placed in
+ System RAM which is dynamically allocated during intialization.
+ Placing the scrollback buffer in System RAM will slightly slow
+ down the console.
+
+ If you want this feature, say 'Y' here and enter the amount of
+ RAM to allocate for this buffer. If unsure, say 'N'.
+
+config VGACON_SOFT_SCROLLBACK_SIZE
+ int "Scrollback Buffer Size (in KB)"
+ depends on VGACON_SOFT_SCROLLBACK
+ default "64"
+ help
+ Enter the amount of System RAM to allocate for the scrollback
+ buffer. Each 64KB will give you approximately 16 80x25
+ screenfuls of scrollback buffer
+
config VIDEO_SELECT
bool "Video mode selection support"
depends on X86 && VGA_CONSOLE
diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index 61894d5..d5a04b6 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -93,7 +93,6 @@ static u8 vgacon_build_attr(struct vc_data *c, u8 color, u8 intensity,
static void vgacon_invert_region(struct vc_data *c, u16 * p, int count);
static unsigned long vgacon_uni_pagedir[2];
-
/* Description of the hardware situation */
static unsigned long vga_vram_base; /* Base of video memory */
static unsigned long vga_vram_end; /* End of video memory */
@@ -161,6 +160,201 @@ static inline void write_vga(unsigned char reg, unsigned int val)
spin_unlock_irqrestore(&vga_lock, flags);
}
+static inline void vga_set_mem_top(struct vc_data *c)
+{
+ write_vga(12, (c->vc_visible_origin - vga_vram_base) / 2);
+}
+
+#ifdef CONFIG_VGACON_SOFT_SCROLLBACK
+#include <linux/bootmem.h>
+/* software scrollback */
+static void *vgacon_scrollback;
+static int vgacon_scrollback_tail;
+static int vgacon_scrollback_size;
+static int vgacon_scrollback_rows;
+static int vgacon_scrollback_cnt;
+static int vgacon_scrollback_cur;
+static int vgacon_scrollback_save;
+static int vgacon_scrollback_restore;
+
+static void vgacon_scrollback_init(int pitch)
+{
+ int rows = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024/pitch;
+
+ if (vgacon_scrollback) {
+ vgacon_scrollback_cnt = 0;
+ vgacon_scrollback_tail = 0;
+ vgacon_scrollback_cur = 0;
+ vgacon_scrollback_rows = rows - 1;
+ vgacon_scrollback_size = rows * pitch;
+ }
+}
+
+static void __init vgacon_scrollback_startup(void)
+{
+ vgacon_scrollback = alloc_bootmem(CONFIG_VGACON_SOFT_SCROLLBACK_SIZE
+ * 1024);
+ vgacon_scrollback_init(vga_video_num_columns * 2);
+}
+
+static void vgacon_scrollback_update(struct vc_data *c, int t, int count)
+{
+ void *p;
+
+ if (!vgacon_scrollback_size || c->vc_num != fg_console)
+ return;
+
+ p = (void *) (c->vc_origin + t * c->vc_size_row);
+
+ while (count--) {
+ scr_memcpyw(vgacon_scrollback + vgacon_scrollback_tail,
+ p, c->vc_size_row);
+ vgacon_scrollback_cnt++;
+ p += c->vc_size_row;
+ vgacon_scrollback_tail += c->vc_size_row;
+
+ if (vgacon_scrollback_tail >= vgacon_scrollback_size)
+ vgacon_scrollback_tail = 0;
+
+ if (vgacon_scrollback_cnt > vgacon_scrollback_rows)
+ vgacon_scrollback_cnt = vgacon_scrollback_rows;
+
+ vgacon_scrollback_cur = vgacon_scrollback_cnt;
+ }
+}
+
+static void vgacon_restore_screen(struct vc_data *c)
+{
+ vgacon_scrollback_save = 0;
+
+ if (!vga_is_gfx && !vgacon_scrollback_restore) {
+ 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_scrollback_restore = 1;
+ vgacon_scrollback_cur = vgacon_scrollback_cnt;
+ }
+}
+
+static int vgacon_scrolldelta(struct vc_data *c, int lines)
+{
+ int start, end, count, soff, diff;
+ void *d, *s;
+
+ if (!lines) {
+ c->vc_visible_origin = c->vc_origin;
+ vga_set_mem_top(c);
+ return 1;
+ }
+
+ if (!vgacon_scrollback)
+ return 1;
+
+ if (!vgacon_scrollback_save) {
+ vgacon_cursor(c, CM_ERASE);
+ vgacon_save_screen(c);
+ vgacon_scrollback_save = 1;
+ }
+
+ vgacon_scrollback_restore = 0;
+ start = vgacon_scrollback_cur + lines;
+ end = start + abs(lines);
+
+ if (start < 0)
+ start = 0;
+
+ if (start > vgacon_scrollback_cnt)
+ start = vgacon_scrollback_cnt;
+
+ if (end < 0)
+ end = 0;
+
+ if (end > vgacon_scrollback_cnt)
+ end = vgacon_scrollback_cnt;
+
+ vgacon_scrollback_cur = start;
+ count = end - start;
+ soff = vgacon_scrollback_tail - ((vgacon_scrollback_cnt - end) *
+ c->vc_size_row);
+ soff -= count * c->vc_size_row;
+
+ if (soff < 0)
+ soff += vgacon_scrollback_size;
+
+ count = vgacon_scrollback_cnt - start;
+
+ if (count > c->vc_rows)
+ count = c->vc_rows;
+
+ diff = c->vc_rows - count;
+
+ d = (void *) c->vc_origin;
+ s = (void *) c->vc_screenbuf;
+
+ while (count--) {
+ scr_memcpyw(d, vgacon_scrollback + soff, c->vc_size_row);
+ d += c->vc_size_row;
+ soff += c->vc_size_row;
+
+ if (soff >= vgacon_scrollback_size)
+ soff = 0;
+ }
+
+ if (diff == c->vc_rows) {
+ vgacon_cursor(c, CM_MOVE);
+ } else {
+ while (diff--) {
+ scr_memcpyw(d, s, c->vc_size_row);
+ d += c->vc_size_row;
+ s += c->vc_size_row;
+ }
+ }
+
+ return 1;
+}
+#else
+#define vgacon_scrollback_startup(...) do { } while (0)
+#define vgacon_scrollback_init(...) do { } while (0)
+#define vgacon_scrollback_update(...) do { } while (0)
+
+static void vgacon_restore_screen(struct vc_data *c)
+{
+ if (c->vc_origin != c->vc_visible_origin)
+ vgacon_scrolldelta(c, 0);
+}
+
+static int vgacon_scrolldelta(struct vc_data *c, int lines)
+{
+ if (!lines) /* Turn scrollback off */
+ c->vc_visible_origin = c->vc_origin;
+ else {
+ int margin = c->vc_size_row * 4;
+ int ul, we, p, st;
+
+ if (vga_rolled_over >
+ (c->vc_scr_end - vga_vram_base) + margin) {
+ ul = c->vc_scr_end - vga_vram_base;
+ we = vga_rolled_over + c->vc_size_row;
+ } else {
+ ul = 0;
+ we = vga_vram_size;
+ }
+ p = (c->vc_visible_origin - vga_vram_base - ul + we) % we +
+ lines * c->vc_size_row;
+ st = (c->vc_origin - vga_vram_base - ul + we) % we;
+ if (st < 2 * margin)
+ margin = 0;
+ if (p < margin)
+ p = 0;
+ if (p > st - margin)
+ p = st;
+ c->vc_visible_origin = vga_vram_base + (p + ul) % we;
+ }
+ vga_set_mem_top(c);
+ return 1;
+}
+#endif /* CONFIG_VGACON_SOFT_SCROLLBACK */
+
static const char __init *vgacon_startup(void)
{
const char *display_desc = NULL;
@@ -330,7 +524,7 @@ static const char __init *vgacon_startup(void)
vgacon_xres = ORIG_VIDEO_COLS * VGA_FONTWIDTH;
vgacon_yres = vga_scan_lines;
-
+ vgacon_scrollback_startup();
return display_desc;
}
@@ -357,11 +551,6 @@ static void vgacon_init(struct vc_data *c, int init)
con_set_default_unimap(c);
}
-static inline void vga_set_mem_top(struct vc_data *c)
-{
- write_vga(12, (c->vc_visible_origin - vga_vram_base) / 2);
-}
-
static void vgacon_deinit(struct vc_data *c)
{
/* When closing the last console, reset video origin */
@@ -455,8 +644,8 @@ static void vgacon_set_cursor_size(int xpos, int from, int to)
static void vgacon_cursor(struct vc_data *c, int mode)
{
- if (c->vc_origin != c->vc_visible_origin)
- vgacon_scrolldelta(c, 0);
+ vgacon_restore_screen(c);
+
switch (mode) {
case CM_ERASE:
write_vga(14, (c->vc_pos - vga_vram_base) / 2);
@@ -606,6 +795,7 @@ static int vgacon_switch(struct vc_data *c)
vgacon_doresize(c, c->vc_cols, c->vc_rows);
}
+ vgacon_scrollback_init(c->vc_size_row);
return 0; /* Redrawing not needed */
}
@@ -1073,37 +1263,6 @@ static int vgacon_resize(struct vc_data *c, unsigned int width,
return 0;
}
-static int vgacon_scrolldelta(struct vc_data *c, int lines)
-{
- if (!lines) /* Turn scrollback off */
- c->vc_visible_origin = c->vc_origin;
- else {
- int margin = c->vc_size_row * 4;
- int ul, we, p, st;
-
- if (vga_rolled_over >
- (c->vc_scr_end - vga_vram_base) + margin) {
- ul = c->vc_scr_end - vga_vram_base;
- we = vga_rolled_over + c->vc_size_row;
- } else {
- ul = 0;
- we = vga_vram_size;
- }
- p = (c->vc_visible_origin - vga_vram_base - ul + we) % we +
- lines * c->vc_size_row;
- st = (c->vc_origin - vga_vram_base - ul + we) % we;
- if (st < 2 * margin)
- margin = 0;
- if (p < margin)
- p = 0;
- if (p > st - margin)
- p = st;
- c->vc_visible_origin = vga_vram_base + (p + ul) % we;
- }
- vga_set_mem_top(c);
- return 1;
-}
-
static int vgacon_set_origin(struct vc_data *c)
{
if (vga_is_gfx || /* We don't play origin tricks in graphic modes */
@@ -1146,15 +1305,14 @@ static int vgacon_scroll(struct vc_data *c, int t, int b, int dir,
if (t || b != c->vc_rows || vga_is_gfx)
return 0;
- if (c->vc_origin != c->vc_visible_origin)
- vgacon_scrolldelta(c, 0);
-
if (!vga_hardscroll_enabled || lines >= c->vc_rows / 2)
return 0;
+ vgacon_restore_screen(c);
oldo = c->vc_origin;
delta = lines * c->vc_size_row;
if (dir == SM_UP) {
+ vgacon_scrollback_update(c, t, lines);
if (c->vc_scr_end + delta >= vga_vram_end) {
scr_memcpyw((u16 *) vga_vram_base,
(u16 *) (oldo + delta),