Say Y.
-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 initialization.
- 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
- range 1 1024
- default "64"
- help
- Enter the amount of System RAM to allocate for scrollback
- buffers of VGA consoles. Each 64KB will give you approximately
- 16 80x25 screenfuls of scrollback buffer.
-
-config VGACON_SOFT_SCROLLBACK_PERSISTENT_ENABLE_BY_DEFAULT
- bool "Persistent Scrollback History for each console by default"
- depends on VGACON_SOFT_SCROLLBACK
- default n
- help
- Say Y here if the scrollback history should persist by default when
- switching between consoles. Otherwise, the scrollback history will be
- flushed each time the console is switched. This feature can also be
- enabled using the boot command line parameter
- 'vgacon.scrollback_persistent=1'.
-
- This feature might break your tool of choice to flush the scrollback
- buffer, e.g. clear(1) will work fine but Debian's clear_console(1)
- will be broken, which might cause security issues.
- You can use the escape sequence \e[3J instead if this feature is
- activated.
-
- Note that a buffer of VGACON_SOFT_SCROLLBACK_SIZE is taken for each
- created tty device.
- So if you use a RAM-constrained system, say N here.
-
config MDA_CONSOLE
depends on !M68K && !PARISC && ISA
tristate "MDA text console (dual-headed)"
write_vga(12, (c->vc_visible_origin - vga_vram_base) / 2);
}
-#ifdef CONFIG_VGACON_SOFT_SCROLLBACK
-/* software scrollback */
-struct vgacon_scrollback_info {
- void *data;
- int tail;
- int size;
- int rows;
- int cnt;
- int cur;
- int save;
- int restore;
-};
-
-static struct vgacon_scrollback_info *vgacon_scrollback_cur;
-static struct vgacon_scrollback_info vgacon_scrollbacks[MAX_NR_CONSOLES];
-static bool scrollback_persistent = \
- IS_ENABLED(CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT_ENABLE_BY_DEFAULT);
-module_param_named(scrollback_persistent, scrollback_persistent, bool, 0000);
-MODULE_PARM_DESC(scrollback_persistent, "Enable persistent scrollback for all vga consoles");
-
-static void vgacon_scrollback_reset(int vc_num, size_t reset_size)
-{
- struct vgacon_scrollback_info *scrollback = &vgacon_scrollbacks[vc_num];
-
- if (scrollback->data && reset_size > 0)
- memset(scrollback->data, 0, reset_size);
-
- scrollback->cnt = 0;
- scrollback->tail = 0;
- scrollback->cur = 0;
-}
-
-static void vgacon_scrollback_init(int vc_num)
-{
- int pitch = vga_video_num_columns * 2;
- size_t size = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024;
- int rows = size / pitch;
- void *data;
-
- data = kmalloc_array(CONFIG_VGACON_SOFT_SCROLLBACK_SIZE, 1024,
- GFP_NOWAIT);
-
- vgacon_scrollbacks[vc_num].data = data;
- vgacon_scrollback_cur = &vgacon_scrollbacks[vc_num];
-
- vgacon_scrollback_cur->rows = rows - 1;
- vgacon_scrollback_cur->size = rows * pitch;
-
- vgacon_scrollback_reset(vc_num, size);
-}
-
-static void vgacon_scrollback_switch(int vc_num)
-{
- if (!scrollback_persistent)
- vc_num = 0;
-
- if (!vgacon_scrollbacks[vc_num].data) {
- vgacon_scrollback_init(vc_num);
- } else {
- if (scrollback_persistent) {
- vgacon_scrollback_cur = &vgacon_scrollbacks[vc_num];
- } else {
- size_t size = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024;
-
- vgacon_scrollback_reset(vc_num, size);
- }
- }
-}
-
-static void vgacon_scrollback_startup(void)
-{
- vgacon_scrollback_cur = &vgacon_scrollbacks[0];
- vgacon_scrollback_init(0);
-}
-
-static void vgacon_scrollback_update(struct vc_data *c, int t, int count)
-{
- void *p;
-
- if (!vgacon_scrollback_cur->data || !vgacon_scrollback_cur->size ||
- c->vc_num != fg_console)
- return;
-
- p = (void *) (c->vc_origin + t * c->vc_size_row);
-
- while (count--) {
- if ((vgacon_scrollback_cur->tail + c->vc_size_row) >
- vgacon_scrollback_cur->size)
- vgacon_scrollback_cur->tail = 0;
-
- scr_memcpyw(vgacon_scrollback_cur->data +
- vgacon_scrollback_cur->tail,
- p, c->vc_size_row);
-
- vgacon_scrollback_cur->cnt++;
- p += c->vc_size_row;
- vgacon_scrollback_cur->tail += c->vc_size_row;
-
- if (vgacon_scrollback_cur->tail >= vgacon_scrollback_cur->size)
- vgacon_scrollback_cur->tail = 0;
-
- if (vgacon_scrollback_cur->cnt > vgacon_scrollback_cur->rows)
- vgacon_scrollback_cur->cnt = vgacon_scrollback_cur->rows;
-
- vgacon_scrollback_cur->cur = vgacon_scrollback_cur->cnt;
- }
-}
-
-static void vgacon_restore_screen(struct vc_data *c)
-{
- c->vc_origin = c->vc_visible_origin;
- vgacon_scrollback_cur->save = 0;
-
- if (!vga_is_gfx && !vgacon_scrollback_cur->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_cur->restore = 1;
- vgacon_scrollback_cur->cur = vgacon_scrollback_cur->cnt;
- }
-}
-
-static void vgacon_scrolldelta(struct vc_data *c, int lines)
-{
- int start, end, count, soff;
-
- if (!lines) {
- vgacon_restore_screen(c);
- return;
- }
-
- if (!vgacon_scrollback_cur->data)
- return;
-
- if (!vgacon_scrollback_cur->save) {
- vgacon_cursor(c, CM_ERASE);
- vgacon_save_screen(c);
- c->vc_origin = (unsigned long)c->vc_screenbuf;
- vgacon_scrollback_cur->save = 1;
- }
-
- vgacon_scrollback_cur->restore = 0;
- start = vgacon_scrollback_cur->cur + lines;
- end = start + abs(lines);
-
- if (start < 0)
- start = 0;
-
- if (start > vgacon_scrollback_cur->cnt)
- start = vgacon_scrollback_cur->cnt;
-
- if (end < 0)
- end = 0;
-
- if (end > vgacon_scrollback_cur->cnt)
- end = vgacon_scrollback_cur->cnt;
-
- vgacon_scrollback_cur->cur = start;
- count = end - start;
- soff = vgacon_scrollback_cur->tail -
- ((vgacon_scrollback_cur->cnt - end) * c->vc_size_row);
- soff -= count * c->vc_size_row;
-
- if (soff < 0)
- soff += vgacon_scrollback_cur->size;
-
- count = vgacon_scrollback_cur->cnt - start;
-
- if (count > c->vc_rows)
- count = c->vc_rows;
-
- if (count) {
- int copysize;
-
- int diff = c->vc_rows - count;
- void *d = (void *) c->vc_visible_origin;
- void *s = (void *) c->vc_screenbuf;
-
- count *= c->vc_size_row;
- /* how much memory to end of buffer left? */
- copysize = min(count, vgacon_scrollback_cur->size - soff);
- scr_memcpyw(d, vgacon_scrollback_cur->data + soff, copysize);
- d += copysize;
- count -= copysize;
-
- if (count) {
- scr_memcpyw(d, vgacon_scrollback_cur->data, count);
- d += count;
- }
-
- if (diff)
- scr_memcpyw(d, s, diff * c->vc_size_row);
- } else
- vgacon_cursor(c, CM_MOVE);
-}
-
-static void vgacon_flush_scrollback(struct vc_data *c)
-{
- size_t size = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024;
-
- vgacon_scrollback_reset(c->vc_num, size);
-}
-#else
-#define vgacon_scrollback_startup(...) do { } while (0)
-#define vgacon_scrollback_init(...) do { } while (0)
-#define vgacon_scrollback_update(...) do { } while (0)
-#define vgacon_scrollback_switch(...) do { } while (0)
-
static void vgacon_restore_screen(struct vc_data *c)
{
if (c->vc_origin != c->vc_visible_origin)
vga_set_mem_top(c);
}
-static void vgacon_flush_scrollback(struct vc_data *c)
-{
-}
-#endif /* CONFIG_VGACON_SOFT_SCROLLBACK */
-
static const char *vgacon_startup(void)
{
const char *display_desc = NULL;
vgacon_xres = screen_info.orig_video_cols * VGA_FONTWIDTH;
vgacon_yres = vga_scan_lines;
- if (!vga_init_done) {
- vgacon_scrollback_startup();
- vga_init_done = true;
- }
+ vga_init_done = true;
return display_desc;
}
vgacon_doresize(c, c->vc_cols, c->vc_rows);
}
- vgacon_scrollback_switch(c->vc_num);
return 0; /* Redrawing not needed */
}
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),
.con_save_screen = vgacon_save_screen,
.con_build_attr = vgacon_build_attr,
.con_invert_region = vgacon_invert_region,
- .con_flush_scrollback = vgacon_flush_scrollback,
};
EXPORT_SYMBOL(vga_con);
projects / kernel.git / commitdiff