Add permanent option for initial DOSBox-X shell

Author: maron2000

dosbox-x.reference.conf

@@ -212,7 +212,7 @@ debuggerrun = debugger
 #           convertdrivefat: If set, DOSBox-X will auto-convert mounted non-FAT drives (such as local drives) to FAT format for use with guest systems.
 #
 # Advanced options (see full configuration reference file [dosbox-x.reference.full.conf] for more details):
-# -> disable graphical splash; allow quit after warning; keyboard hook; weitek; bochs debug port e9; video debug at startup; compresssaveparts; show recorded filename; skip encoding unchanged frames; capture chroma format; capture format; shell environment size; private area size; turn off a20 gate on boot; cbus bus clock; isa bus clock; pci bus clock; call binary on reset; unhandled irq handler; call binary on boot; ibm rom basic; rom bios allocation max; rom bios minimum size; irq delay ns; iodelay; iodelay16; iodelay32; acpi; acpi rsd ptr location; acpi sci irq; acpi iobase; acpi reserved size; memsizekb; dos mem limit; isa memory hole at 512kb; isa memory hole at 15mb; reboot delay; memalias; convert fat free space; convert fat timeout; leading colon write protect image; locking disk image mount; unmask keyboard on int 16 read; int16 keyboard polling undocumented cf behavior; allow port 92 reset; enable port 92; enable 1st dma controller; enable 2nd dma controller; allow dma address decrement; enable 128k capable 16-bit dma; enable dma extra page registers; dma page registers write-only; cascade interrupt never in service; cascade interrupt ignore in service; enable slave pic; enable pc nmi mask; allow more than 640kb base memory; enable pci bus
+# -> disable graphical splash; allow quit after warning; keyboard hook; weitek; bochs debug port e9; video debug at startup; compresssaveparts; show recorded filename; skip encoding unchanged frames; capture chroma format; capture format; shell environment size; shell permanent; private area size; turn off a20 gate on boot; cbus bus clock; isa bus clock; pci bus clock; call binary on reset; unhandled irq handler; call binary on boot; ibm rom basic; rom bios allocation max; rom bios minimum size; irq delay ns; iodelay; iodelay16; iodelay32; acpi; acpi rsd ptr location; acpi sci irq; acpi iobase; acpi reserved size; memsizekb; dos mem limit; isa memory hole at 512kb; isa memory hole at 15mb; reboot delay; memalias; convert fat free space; convert fat timeout; leading colon write protect image; locking disk image mount; unmask keyboard on int 16 read; int16 keyboard polling undocumented cf behavior; allow port 92 reset; enable port 92; enable 1st dma controller; enable 2nd dma controller; allow dma address decrement; enable 128k capable 16-bit dma; enable dma extra page registers; dma page registers write-only; cascade interrupt never in service; cascade interrupt ignore in service; enable slave pic; enable pc nmi mask; allow more than 640kb base memory; enable pci bus
 #
 language                  = 
 title                     = 

dosbox-x.reference.full.conf

@@ -279,6 +279,7 @@ debuggerrun = debugger
 #                          shell environment size: Size of the initial DOSBox-X shell environment block, in bytes. Setting to 0 implies a default size of 720 bytes as in DOSBox.
 #                                                    You can increase this size to store more environment variables in DOS, although this does not affect the environment block
 #                                                    of sub-processes spawned from the DOS shell. This option has no effect unless the dynamic kernel allocation is enabled.
+#                                 shell permanent: If enabled, initial DOSBox-X shell will stay permanent (equivalent to /P switch).
 #                               private area size: Set DOSBox-X private memory area size. This area contains private memory structures used by the DOS kernel.
 #                                                    It is discarded when you boot into another OS. Mainline DOSBox uses 32KB. Testing shows that it is possible
 #                                                    to run DOSBox with as little as 4KB. If DOSBox-X aborts with error "not enough memory for internal tables"
@@ -491,6 +492,7 @@ skip encoding unchanged frames                  = false
 capture chroma format                           = auto
 capture format                                  = default
 shell environment size                          = 0
+shell permanent                                 = false
 private area size                               = 32768
 a20                                             = mask
 turn off a20 gate on boot                       = true

src/dosbox.cpp

@@ -1767,6 +1767,9 @@ void DOSBOX_SetupConfigSections(void) {
                    "You can increase this size to store more environment variables in DOS, although this does not affect the environment block\n"
                    "of sub-processes spawned from the DOS shell. This option has no effect unless the dynamic kernel allocation is enabled.");
 
+    Pbool = secprop->Add_bool("shell permanent", Property::Changeable::OnlyAtStart, false);
+    Pbool->Set_help("If enabled, initial DOSBox-X shell will stay permanent (equivalent to /P switch).");
+
     Pint = secprop->Add_int("private area size",Property::Changeable::OnlyAtStart,32768); // DOSBox mainline compatible 32KB region
     Pint->SetMinMax(16,128*1024);
     Pint->Set_help("Set DOSBox-X private memory area size. This area contains private memory structures used by the DOS kernel.\n"

src/shell/shell.cpp

@@ -892,6 +892,7 @@ void DOS_Shell::Prepare(void) {
         }
         Section_prop *section = static_cast<Section_prop *>(control->GetSection("dosbox"));
         bool startbanner = section->Get_bool("startbanner");
+        first_shell->perm = section->Get_bool("shell permanent");
         if (!countryNo) {
 #if defined(WIN32)
 			char buffer[128];