Make sure new tasks are created with the interrupt flag set. Don't leave interrupts disabled unless necessary.

This fixes the command "run exclusive my_doom.exe".
More work needs to be done before "run my_doom.exe" will work.

Author: tthomps

MyOS_1/Build_Number.h

@@ -3,4 +3,4 @@
 // Define a build number. This number will be incremented by a simple console program called by a post-build event
 // It's put here in its own file to keep the other program from messing up the source
 #define \
-BUILD_NUMBER 6464
+BUILD_NUMBER 6507

MyOS_1/Executables/PE32.c

@@ -82,7 +82,7 @@ bool loadAndRunPE(uint8_t *executableDestination, DOS_Header *mzAddress, const c
         }
     }
 
-    // Disable interrupts
+    // Disable interrupts while we mess with page tables
     _disable();
 
     // Get a new page directory for the new task
@@ -119,6 +119,9 @@ bool loadAndRunPE(uint8_t *executableDestination, DOS_Header *mzAddress, const c
     else
         newPageDirectory = pageDir;
 
+    // It's safe for interrupts to run again; we're done messing with the page tables
+    _enable();
+
     // TEMPTEMP - zero out 5 0x1000 sections of memory (tailored to TestApp1.exe)
     memset((void*)physicalLocation, 0, 0x5000);
 

MyOS_1/Tasks/Dispatcher.c

@@ -90,15 +90,15 @@ void CloseApp(uint32_t PID)
 
 void DispatchNewTask(uint32_t programStart, PAGE_DIRECTORY_ENTRY *newPageDirectory, uint32_t stackSize, const char *imageName, bool exclusive)
 {
-    // disable interrupts
-    __asm cli
-
     if (debugLevel)
     {
         kprintf("Dispatching %s\n", imageName);
         kprintf("program starts at 0x%lX\n", programStart);
     }
 
+    // disable interrupts while we mess with task slots
+    _disable();
+
     // Find a free task slot
     uint16_t taskSlot;
     for (taskSlot = 0; taskSlot < MAX_TASKS; ++taskSlot)
@@ -180,10 +180,12 @@ void DispatchNewTask(uint32_t programStart, PAGE_DIRECTORY_ENTRY *newPageDirecto
     // setup stack for the task, and copy the stack to stackPtr
     __asm
     {
+        sti
         push esp
         push [stackPtr]
         int SYSCALL_DISPATCH_NEW_TASK   // call dispatch_new_task_interrupt_handler(eflags, cs, stackPtr, esp)
         add esp, 8
+        cli
     }
 
     // Update the task's "stack image" to represent values appropriate for the new task