Revert "vga: add some optional CGA compatibility hacks"

This reverts commit 482f7bf86b.

Signed-off-by: malc <av1474@comtv.ru>

hw/pc.h

@@ -176,10 +176,6 @@ enum vga_retrace_method {
 
 extern enum vga_retrace_method vga_retrace_method;
 
-#define VGA_CGA_HACK_PALETTE_BLANKING  (1<<0)
-#define VGA_CGA_HACK_FONT_HEIGHT       (1<<1)
-extern int vga_cga_hacks;
-
 static inline DeviceState *isa_vga_init(ISABus *bus)
 {
     ISADevice *dev;

hw/vga.c

@@ -547,31 +547,14 @@ void vga_ioport_write(void *opaque, uint32_t addr, uint32_t val)
         printf("vga: write CR%x = 0x%02x\n", s->cr_index, val);
 #endif
         /* handle CR0-7 protection */
-        if (s->cr[VGA_CRTC_V_SYNC_END] & VGA_CR11_LOCK_CR0_CR7) {
+        if ((s->cr[VGA_CRTC_V_SYNC_END] & VGA_CR11_LOCK_CR0_CR7) &&
-            if (s->cr_index <= VGA_CRTC_OVERFLOW) {
+            s->cr_index <= VGA_CRTC_OVERFLOW) {
-                /* can always write bit 4 of CR7 */
+            /* can always write bit 4 of CR7 */
-                if (s->cr_index == VGA_CRTC_OVERFLOW) {
+            if (s->cr_index == VGA_CRTC_OVERFLOW) {
-                    s->cr[VGA_CRTC_OVERFLOW] =
+                s->cr[VGA_CRTC_OVERFLOW] = (s->cr[VGA_CRTC_OVERFLOW] & ~0x10) |
-                        (s->cr[VGA_CRTC_OVERFLOW] & ~0x10) | (val & 0x10);
+                    (val & 0x10);
-                }
-                return;
-            } else if ((vga_cga_hacks & VGA_CGA_HACK_FONT_HEIGHT) &&
-                       !(s->sr[VGA_SEQ_CLOCK_MODE] & VGA_SR01_CHAR_CLK_8DOTS)) {
-                /* extra CGA compatibility hacks (not in standard VGA) */
-                if (s->cr_index == VGA_CRTC_MAX_SCAN &&
-                    val == 7 &&
-                    (s->cr[VGA_CRTC_MAX_SCAN] & 0xf) == 0xf) {
-                    return;
-                } else if (s->cr_index == VGA_CRTC_CURSOR_START &&
-                           val == 6 &&
-                           (s->cr[VGA_CRTC_MAX_SCAN] & 0xf) == 0xf) {
-                    val = 0xd;
-                } else if (s->cr_index == VGA_CRTC_CURSOR_END &&
-                           val == 7 &&
-                           (s->cr[VGA_CRTC_MAX_SCAN] & 0xf) == 0xf) {
-                    val = 0xe;
-                }
             }
+            return;
         }
         s->cr[s->cr_index] = val;
 
@@ -1903,10 +1886,7 @@ static void vga_update_display(void *opaque)
         /* nothing to do */
     } else {
         full_update = 0;
-        if (!(s->ar_index & 0x20) &&
+        if (!(s->ar_index & 0x20)) {
-            /* extra CGA compatibility hacks (not in standard VGA */
-            (!(vga_cga_hacks & VGA_CGA_HACK_PALETTE_BLANKING) ||
-             (s->ar_index != 0 && s->ar_flip_flop))) {
             graphic_mode = GMODE_BLANK;
         } else {
             graphic_mode = s->gr[VGA_GFX_MISC] & VGA_GR06_GRAPHICS_MODE;

qemu-options.hx

@@ -975,25 +975,6 @@ Valid optional properties are
 @item retrace=dumb|precise
 Select dumb (default) or precise VGA retrace logic, useful for some
 DOS games/demos.
-@item cga_hacks=@var{hack1}[+@var{hack2},[...]]
-Enable various extra CGA compatibility hacks for programs that are
-trying to directly set CGA modes without BIOS assistance nor
-real knowledge of EGA/VGA.  These might only work with -vga std.
-Valid hacks are
-@table @option
-@item palette_blanking
-Wait to blank the screen until palette registers seem to actually be
-modified, instead of blanking it as soon as the palette address bit (0x10)
-of the attribute address register (0x3c0) is cleared.
-@item font_height
-Ignore attempts to change the VGA font height (index 9),
-cursor start (index 10), and cursor end (index 11) of the CRTC control
-registers (0x3d5) if trying to set them to the default for CGA fonts
-instead of VGA fonts.
-@item all
-Enable all CGA hacks.  More CGA hacks may be added in future versions
-of qemu.
-@end table
 @end table
 ETEXI
 

vl.c

@@ -179,7 +179,6 @@ int main(int argc, char **argv)
 static const char *data_dir;
 const char *bios_name = NULL;
 enum vga_retrace_method vga_retrace_method = VGA_RETRACE_DUMB;
-int vga_cga_hacks = 0;
 DisplayType display_type = DT_DEFAULT;
 int display_remote = 0;
 const char* keyboard_layout = NULL;
@@ -1749,28 +1748,6 @@ static void select_vgahw (const char *p)
             else if (strstart(opts, "precise", &nextopt))
                 vga_retrace_method = VGA_RETRACE_PRECISE;
             else goto invalid_vga;
-        } else if (strstart(opts, ",cga_hacks=", &nextopt)) {
-            opts = nextopt;
-            while (*opts) {
-                if (strstart(opts, "all", &nextopt)) {
-                    opts = nextopt;
-                    vga_cga_hacks |= ~0;
-                } else if (strstart(opts, "palette_blanking", &nextopt)) {
-                    opts = nextopt;
-                    vga_cga_hacks |= VGA_CGA_HACK_PALETTE_BLANKING;
-                } else if (strstart(opts, "font_height", &nextopt)) {
-                    opts = nextopt;
-                    vga_cga_hacks |= VGA_CGA_HACK_FONT_HEIGHT;
-                } else {
-                    break;
-                }
-
-                if (*opts == '+') {
-                    opts++;
-                } else {
-                    break;
-                }
-            }
         } else goto invalid_vga;
         opts = nextopt;
     }