Matrox MGA fixes:

1. When the 128K banking is activated, use a mask of 0xffff instead of 0x1ffff.
2. Debian uses standard VGA mapping when in chain4 mode and its lfb is adapted accordingly.
3. Fixed the decode VRAM mask on the Millennium II so that the vram is detected correctly and no more glitches.
4. Undev the Millennium II as well.

src/include/86box/video.h

@@ -439,8 +439,8 @@ extern const device_t pgc_device;
 extern const device_t millennium_device;
 extern const device_t mystique_device;
 extern const device_t mystique_220_device;
-#    if defined(DEV_BRANCH) && defined(USE_MGA2)
 extern const device_t millennium_ii_device;
+#    if defined(DEV_BRANCH) && defined(USE_MGA2)
 extern const device_t productiva_g100_device;
 #    endif
 

src/video/vid_mga.c

@@ -1137,7 +1137,7 @@ mystique_recalc_mapping(mystique_t *mystique)
         switch (svga->gdcreg[6] & 0x0C) {
             case 0x0: /*128k at A0000*/
                 mem_mapping_set_addr(&svga->mapping, 0xa0000, 0x20000);
-                svga->banked_mask = 0x1ffff;
+                svga->banked_mask = 0xffff;
                 break;
             case 0x4: /*64k at A0000*/
                 mem_mapping_set_addr(&svga->mapping, 0xa0000, 0x10000);
@@ -2812,13 +2812,21 @@ mystique_readb_linear(uint32_t addr, void *priv)
     const svga_t *svga = (svga_t *) priv;
     mystique_t *mystique = (mystique_t *) svga->priv;
 
-    if (mystique->type < MGA_1064SG) {
-        if (!svga->fast)
-            return svga_read_linear(addr, priv);
-    }
-
     cycles -= svga->monitor->mon_video_timing_read_b;
 
+    if ((svga->chain4 && (svga->packed_chain4 || svga->force_old_addr)) || svga->fb_only) {
+        addr &= svga->decode_mask;
+        if (addr >= svga->vram_max)
+            return 0xff;
+
+        return svga->vram[addr & svga->vram_mask];
+    } else if (svga->chain4 && !svga->force_old_addr) {
+        addr      = ((addr & 0xfffc) << 2) | ((addr & 0x30000) >> 14) | (addr & ~0x3ffff);
+    } else if (svga->chain2_read) {
+        addr &= ~1;
+        addr <<= 2;
+    }
+
     addr &= svga->decode_mask;
     if (addr >= svga->vram_max)
         return 0xff;
@@ -2860,15 +2868,17 @@ mystique_writeb_linear(uint32_t addr, uint8_t val, void *priv)
     svga_t *svga = (svga_t *) priv;
     mystique_t *mystique = (mystique_t *) svga->priv;
 
-    if (mystique->type < MGA_1064SG) {
-        if (!svga->fast) {
-            svga_write_linear(addr, val, priv);
-            return;
-        }
-    }
-
     cycles -= svga->monitor->mon_video_timing_write_b;
 
+    if (((svga->chain4 && (svga->packed_chain4 || svga->force_old_addr)) || svga->fb_only) && (svga->writemode < 4)) {
+        addr &= ~3;
+    } else if (svga->chain4 && (svga->writemode < 4)) {
+        addr = ((addr & 0xfffc) << 2) | ((addr & 0x30000) >> 14) | (addr & ~0x3ffff);
+    } else if (svga->chain2_write) {
+        addr &= ~1;
+        addr <<= 2;
+    }
+
     addr &= svga->decode_mask;
     if (addr >= svga->vram_max)
         return;
@@ -6401,8 +6411,8 @@ mystique_init(const device_t *info)
         mystique->svga.clock_gen         = mystique->svga.ramdac;
         mystique->svga.getclock          = tvp3026_getclock;
         mystique->svga.conv_16to32       = tvp3026_conv_16to32;
-        if (mystique->vram_size >= 16)
-            mystique->svga.decode_mask = mystique->svga.vram_mask;
+        if (mystique->type == MGA_2164W)
+            mystique->svga.decode_mask = 0xffffff;
         tvp3026_gpio(mystique_tvp3026_gpio_read, mystique_tvp3026_gpio_write, mystique, mystique->svga.ramdac);
     } else {
         video_inform(VIDEO_FLAG_TYPE_SPECIAL, &timing_matrox_mystique);
@@ -6413,8 +6423,8 @@ mystique_init(const device_t *info)
                   NULL);
         mystique->svga.clock_gen = mystique;
         mystique->svga.getclock  = mystique_getclock;
-        if (mystique->vram_size >= 16)
-            mystique->svga.decode_mask = mystique->svga.vram_mask;
+        if (mystique->type == MGA_G100)
+            mystique->svga.decode_mask = 0xffffff;
     }
 
     io_sethandler(0x03c0, 0x0020, mystique_in, NULL, NULL, mystique_out, NULL, NULL, mystique);
@@ -6541,13 +6551,13 @@ mystique_220_available(void)
     return rom_present(ROM_MYSTIQUE_220);
 }
 
-#if defined(DEV_BRANCH) && defined(USE_MGA2)
 static int
 millennium_ii_available(void)
 {
     return rom_present(ROM_MILLENNIUM_II);
 }
 
+#if defined(DEV_BRANCH) && defined(USE_MGA2)
 static int
 matrox_g100_available(void)
 {
@@ -6603,7 +6613,6 @@ static const device_config_t mystique_config[] = {
   // clang-format on
 };
 
-#if defined(DEV_BRANCH) && defined(USE_MGA2)
 static const device_config_t millennium_ii_config[] = {
   // clang-format off
     {
@@ -6635,7 +6644,6 @@ static const device_config_t millennium_ii_config[] = {
     }
   // clang-format on
 };
-#endif
 
 const device_t millennium_device = {
     .name          = "Matrox Millennium",
@@ -6679,7 +6687,6 @@ const device_t mystique_220_device = {
     .config        = mystique_config
 };
 
-#if defined(DEV_BRANCH) && defined(USE_MGA2)
 const device_t millennium_ii_device = {
     .name          = "Matrox Millennium II",
     .internal_name = "millennium_ii",
@@ -6694,6 +6701,7 @@ const device_t millennium_ii_device = {
     .config        = millennium_ii_config
 };
 
+#if defined(DEV_BRANCH) && defined(USE_MGA2)
 const device_t productiva_g100_device = {
     .name          = "Matrox Productiva G100",
     .internal_name = "productiva_g100",

src/video/vid_table.c

@@ -209,9 +209,7 @@ video_cards[] = {
     { &s3_trio3d2x_pci_device                          },
     { &chips_69000_device                              },
     { &millennium_device                               },
-#if defined(DEV_BRANCH) && defined(USE_MGA2)
     { &millennium_ii_device                            },
-#endif
     { &mystique_device                                 },
     { &mystique_220_device                             },
     { &tgui9440_pci_device                             },