Change ISA memory hole option 512kb to true/false/auto

maron2000 · Oct 9, 2023 · dc9e0ff · dc9e0ff
1 parent 2a1ea2d
commit dc9e0ff
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Showing 5 changed files with 18 additions and 6 deletions.
diff --git a/CHANGELOG b/CHANGELOG
@@ -1,5 +1,5 @@
 Next:
-  - 
+  - Change ISA memory hole 512kb option from boolean to true/false/auto.
 
 2023.10.06
   - Add "VRD" debugger command to force redraw of the VGA screen.

diff --git a/contrib/windows/installer/dosbox-x.reference.setup.conf b/contrib/windows/installer/dosbox-x.reference.setup.conf
@@ -379,6 +379,7 @@ debuggerrun = debugger
 #DOSBOX-X-ADV:#                                                    A few DOS games & demos require this option to be set:
 #DOSBOX-X-ADV:#                                                         Majic 12 "Show": If UMBs are enabled, set this option to 639 to avoid MCB chain corruption error.
 #DOSBOX-X-ADV:#                        isa memory hole at 512kb: If set, emulate an ISA memory hole at the 512KB to 640KB area (0x80000-0x9FFFF).
+#DOSBOX-X-ADV:#                                                    Possible values: true, false, 1, 0, auto.
 #DOSBOX-X-ADV:#                                    reboot delay: Reboot delay. How long to pause at BIOS POST after reboot in milliseconds.
 #DOSBOX-X-ADV:#                                                    This option is provided so that it is possible to see what the guest application
 #DOSBOX-X-ADV:#                                                    or OS might have written to the screen before resetting the system. A value of
@@ -497,7 +498,7 @@ a20                                             = mask
 memsize                                         = 16
 #DOSBOX-X-ADV:memsizekb                                       = 0
 #DOSBOX-X-ADV:dos mem limit                                   = 0
-#DOSBOX-X-ADV:isa memory hole at 512kb                        = false
+#DOSBOX-X-ADV:isa memory hole at 512kb                        = auto
 #DOSBOX-X-ADV:reboot delay                                    = -1
 #DOSBOX-X-ADV:memalias                                        = 0
 nocachedir                                      = false

diff --git a/dosbox-x.reference.full.conf b/dosbox-x.reference.full.conf
@@ -371,6 +371,7 @@ debuggerrun = debugger
 #                                                    A few DOS games & demos require this option to be set:
 #                                                         Majic 12 "Show": If UMBs are enabled, set this option to 639 to avoid MCB chain corruption error.
 #                        isa memory hole at 512kb: If set, emulate an ISA memory hole at the 512KB to 640KB area (0x80000-0x9FFFF).
+#                                                    Possible values: true, false, 1, 0, auto.
 #                                    reboot delay: Reboot delay. How long to pause at BIOS POST after reboot in milliseconds.
 #                                                    This option is provided so that it is possible to see what the guest application
 #                                                    or OS might have written to the screen before resetting the system. A value of
@@ -485,7 +486,7 @@ acpi reserved size                              = 0
 memsize                                         = 16
 memsizekb                                       = 0
 dos mem limit                                   = 0
-isa memory hole at 512kb                        = false
+isa memory hole at 512kb                        = auto
 reboot delay                                    = -1
 memalias                                        = 0
 nocachedir                                      = false

diff --git a/src/dosbox.cpp b/src/dosbox.cpp
@@ -1800,8 +1800,9 @@ void DOSBOX_SetupConfigSections(void) {
             "A few DOS games & demos require this option to be set:\n"
             "     Majic 12 \"Show\": If UMBs are enabled, set this option to 639 to avoid MCB chain corruption error.");
 
-    Pbool = secprop->Add_bool("isa memory hole at 512kb",Property::Changeable::WhenIdle,false);
-    Pbool->Set_help("If set, emulate an ISA memory hole at the 512KB to 640KB area (0x80000-0x9FFFF).");
+    Pstring = secprop->Add_string("isa memory hole at 512kb",Property::Changeable::WhenIdle,"auto");
+    Pstring->Set_values(truefalseautoopt);
+    Pstring->Set_help("If set, emulate an ISA memory hole at the 512KB to 640KB area (0x80000-0x9FFFF).");
 
     Pint = secprop->Add_int("reboot delay", Property::Changeable::WhenIdle,-1);
     Pint->SetMinMax(-1,10000);

diff --git a/src/ints/bios.cpp b/src/ints/bios.cpp
@@ -9918,7 +9918,16 @@ class BIOS:public Module_base{
             bochs_port_e9 = section->Get_bool("bochs debug port e9");
 
             // TODO: motherboard init, especially when we get around to full Intel Triton/i440FX chipset emulation
-            isa_memory_hole_512kb = section->Get_bool("isa memory hole at 512kb");
+            {
+                std::string s = section->Get_string("isa memory hole at 512kb");
+
+                if (s == "true" || s == "1")
+                    isa_memory_hole_512kb = true;
+                else if (s == "false" || s == "0")
+                    isa_memory_hole_512kb = false;
+                else
+                    isa_memory_hole_512kb = false;
+            }
 
             // FIXME: Erm, well this couldv'e been named better. It refers to the amount of conventional memory
             //        made available to the operating system below 1MB, which is usually DOS.