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authorH. Peter Anvin <hpa@zytor.com>2008-02-13 16:05:06 -0800
committerH. Peter Anvin <hpa@zytor.com>2008-02-13 16:11:53 -0800
commitf7122d423f1eba4e2c620c7599d59d78e9315112 (patch)
treea4f42c3057c4245c86fbfdb92fabcc89ac397293 /com32/lib/sys/vesa/screencpy.c
parent4d459d16f68ebcd8fbac96bf505db5bd1ac337db (diff)
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Add support for paged (banked) VESA video mode
Add support for paged ("banked", non-linear-framebuffer) VESA video modes. Apparently some manufacturers haven't caught on that non-linear graphics modes have been obsolete for 15 years or so already.
Diffstat (limited to 'com32/lib/sys/vesa/screencpy.c')
-rw-r--r--com32/lib/sys/vesa/screencpy.c115
1 files changed, 115 insertions, 0 deletions
diff --git a/com32/lib/sys/vesa/screencpy.c b/com32/lib/sys/vesa/screencpy.c
new file mode 100644
index 00000000..a8be4306
--- /dev/null
+++ b/com32/lib/sys/vesa/screencpy.c
@@ -0,0 +1,115 @@
+/* ----------------------------------------------------------------------- *
+ *
+ * Copyright 2008 H. Peter Anvin - All Rights Reserved
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom
+ * the Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall
+ * be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * ----------------------------------------------------------------------- */
+
+#include <inttypes.h>
+#include <minmax.h>
+#include <klibc/compiler.h>
+#include <string.h>
+#include <com32.h>
+#include "vesa.h"
+#include "video.h"
+
+static struct win_info {
+ char *win_base;
+ size_t win_pos;
+ size_t win_size;
+ int win_gshift;
+ int win_num;
+} wi;
+
+static void *
+vesacon_copy_to_paged_screen(void *dst, const void *src, size_t len);
+
+static inline int __constfunc ilog2(unsigned int x)
+{
+ asm("bsrl %1,%0" : "=r" (x) : "rm" (x));
+ return x;
+}
+
+void __vesacon_init_copy_to_screen(void)
+{
+ struct vesa_mode_info * const mi = &__vesa_info.mi;
+ int winn;
+
+ if (mi->mode_attr & 0x0080) {
+ __vesacon_copy_to_screen = memcpy; /* Really easy... */
+ } else {
+ __vesacon_copy_to_screen = vesacon_copy_to_paged_screen;
+
+ mi->lfb_ptr = 0; /* Zero-base this */
+ wi.win_pos = -1; /* Undefined position */
+
+ /* We have already tested that *one* of these is usable */
+ if ((mi->win_attr[0] & 0x05) == 0x05 && mi->win_seg[0])
+ winn = 0;
+ else
+ winn = 1;
+
+ wi.win_num = winn;
+ wi.win_base = (char *)(mi->win_seg[winn] << 4);
+ wi.win_size = mi->win_size << 10;
+ wi.win_gshift = ilog2(mi->win_grain) + 10;
+ }
+}
+
+static void *
+vesacon_copy_to_paged_screen(void *dst, const void *src, size_t len)
+{
+ size_t win_pos, win_off;
+ size_t win_size = wi.win_size;
+ size_t omask = win_size - 1;
+ char *win_base = wi.win_base;
+ size_t l;
+ size_t d = (size_t)dst;
+ const char *s = src;
+ com32sys_t ireg;
+
+ memset(&ireg, 0, sizeof ireg);
+ ireg.eax.w[0] = 0x4F05; /* VBE Window Control */
+ /* BH = 0 -> Set memory window */
+ ireg.ebx.b[0] = wi.win_num;
+
+ while (len) {
+ win_off = d & omask;
+ win_pos = d & ~omask;
+
+ if (win_pos != wi.win_pos) {
+ ireg.edx.w[0] = win_pos >> wi.win_gshift;
+ __intcall(0x10, &ireg, NULL);
+ wi.win_pos = win_pos;
+ }
+
+ l = min(len, win_size - win_off);
+ memcpy(win_base + win_off, s, l);
+
+ len -= l;
+ s += l;
+ d += l;
+ }
+
+ return dst;
+}