Do not create new bootloader stack as it is not needed any longer and kernel will use its own stack

xtldr/amd64/memory.c

@@ -9,50 +9,6 @@
 #include <xtbl.h>
 
 
-/**
- * Creates and switches to a new stack.
- *
- * @param StackPtr
- *        Supplies a pointer to memory area, where the stack will be created.
- *
- * @param StackSize
- *        Specifies a size (in bytes) of the new stack.
- *
- * @param Callback
- *        Supplies a pointer to a callback function that will be executed on top of new stack.
- *
- * @return This routine does not return any value.
- *
- * @since XT 1.0
- */
-XTCDECL
-VOID
-BlCreateStack(IN PVOID *StackPtr,
-              IN ULONG StackSize,
-              IN PVOID Callback)
-{
-    EFI_PHYSICAL_ADDRESS Address;
-    PVOID StackEnd;
-
-    /* Allocate pages for new stack and calculate its end */
-    BlEfiMemoryAllocatePages(EFI_SIZE_TO_PAGES(StackSize), &Address);
-    *StackPtr = (PVOID)(UINT_PTR)Address;
-    StackEnd = (PUINT8)*StackPtr + (StackSize - EFI_PAGE_SIZE);
-
-    /* Create new stack and switch to it immediatelly by calling callback function */
-    asm volatile("mov %1, %%rax\n"
-                 "mov %%rsp, %%rbx\n"
-                 "mov %0, %%rsp\n"
-                 "push %%rbp\n"
-                 "mov %%rsp, %%rbp\n"
-                 "push %%rbx\n"
-                 "sub $32, %%rsp\n"
-                 "call *%%rax\n"
-                 :
-                 : "m" (StackEnd), "m" (Callback)
-                 : "rax", "rbx");
-}
-
 /**
  * Builds the actual memory mapping page table and enables paging. This routine exits EFI boot services as well.
  *
@@ -84,7 +40,6 @@ BlEnablePaging(IN PLIST_ENTRY MemoryMappings,
     PEFI_MEMORY_MAP MemoryMap;
     PLIST_ENTRY ListEntry;
     EFI_STATUS Status;
-    PVOID Stack;
 
     /* Allocate and zero-fill buffer for EFI memory map */
     BlEfiMemoryAllocatePool(sizeof(EFI_MEMORY_MAP), (PVOID*)&MemoryMap);
@@ -110,16 +65,6 @@ BlEnablePaging(IN PLIST_ENTRY MemoryMappings,
     *PtePointer = (PVOID)(UINT_PTR)Address;
     RtlZeroMemory(*PtePointer, EFI_PAGE_SIZE);
 
-    /* Map the stack */
-    BlGetStackPointer(&Stack);
-    Status = BlAddVirtualMemoryMapping(MemoryMappings, Stack, Stack, EFI_SIZE_TO_PAGES(KERNEL_STACK_SIZE),
-                                       LoaderOsloaderStack);
-    if(Status != STATUS_EFI_SUCCESS)
-    {
-        /* Mapping the stack failed */
-        return Status;
-    }
-
     /* Map XTLDR code */
     Status = BlAddVirtualMemoryMapping(MemoryMappings, ImageProtocol->ImageBase, ImageProtocol->ImageBase,
                                        EFI_SIZE_TO_PAGES(ImageProtocol->ImageSize), LoaderFirmwareTemporary);

xtldr/i686/memory.c

@@ -9,50 +9,6 @@
 #include <xtbl.h>
 
 
-/**
- * Creates and switches to a new stack.
- *
- * @param StackPtr
- *        Supplies a pointer to memory area, where the stack will be created.
- *
- * @param StackSize
- *        Specifies a size (in bytes) of the new stack.
- *
- * @param Callback
- *        Supplies a pointer to a callback function that will be executed on top of new stack.
- *
- * @return This routine does not return any value.
- *
- * @since XT 1.0
- */
-XTCDECL
-VOID
-BlCreateStack(IN PVOID *StackPtr,
-              IN ULONG StackSize,
-              IN PVOID Callback)
-{
-    EFI_PHYSICAL_ADDRESS Address;
-    PVOID StackEnd;
-
-    /* Allocate pages for new stack and calculate its end */
-    BlEfiMemoryAllocatePages(EFI_SIZE_TO_PAGES(StackSize), &Address);
-    *StackPtr = (PVOID)(UINT_PTR)Address;
-    StackEnd = (PUINT8)*StackPtr + (StackSize - EFI_PAGE_SIZE);
-
-    /* Create new stack and switch to it immediatelly by calling callback function */
-    asm volatile("mov %1, %%eax\n"
-                 "mov %%esp, %%ebx\n"
-                 "mov %0, %%esp\n"
-                 "push %%ebp\n"
-                 "mov %%esp, %%ebp\n"
-                 "push %%ebx\n"
-                 "sub $32, %%esp\n"
-                 "call *%%eax\n"
-                 :
-                 : "m" (StackEnd), "m" (Callback)
-                 : "eax", "ebx");
-}
-
 /**
  * Builds the actual memory mapping page table and enables paging. This routine exits EFI boot services as well.
  *
@@ -87,7 +43,6 @@ BlEnablePaging(IN PLIST_ENTRY MemoryMappings,
     PEFI_MEMORY_MAP MemoryMap;
     PLIST_ENTRY ListEntry;
     EFI_STATUS Status;
-    PVOID Stack;
     UINT Index;
 
     /* Prepare CPUID registers */
@@ -196,16 +151,6 @@ BlEnablePaging(IN PLIST_ENTRY MemoryMappings,
         Address += EFI_PAGE_SIZE;
     }
 
-    /* Map the stack */
-    BlGetStackPointer(&Stack);
-    Status = BlAddVirtualMemoryMapping(MemoryMappings, Stack, Stack, EFI_SIZE_TO_PAGES(KERNEL_STACK_SIZE),
-                                       LoaderOsloaderStack);
-    if(Status != STATUS_EFI_SUCCESS)
-    {
-        /* Mapping the stack failed */
-        return Status;
-    }
-
     /* Map XTLDR code */
     Status = BlAddVirtualMemoryMapping(MemoryMappings, ImageProtocol->ImageBase, ImageProtocol->ImageBase,
                                        EFI_SIZE_TO_PAGES(ImageProtocol->ImageSize), LoaderFirmwareTemporary);

xtldr/includes/blproto.h

@@ -43,7 +43,6 @@ typedef struct _XT_BOOT_LOADER_PROTOCOL
     PBL_GET_VIRTUAL_ADDRESS GetVirtualAddress;
     PBL_INIT_VIRTUAL_MEMORY InitializeVirtualMemory;
     PBL_MAP_VIRTUAL_MEMORY MapVirtualMemory;
-    PBL_GET_STACK GetStack;
     PBL_DBG_PRINT DbgPrint;
     PBL_EFI_PRINT EfiPrint;
     PBL_CLOSE_VOLUME CloseVolume;

xtldr/includes/xtbl.h

@@ -72,12 +72,6 @@ XTCDECL
 LOADER_MEMORY_TYPE
 BlConvertEfiMemoryType(IN EFI_MEMORY_TYPE EfiMemoryType);
 
-XTCDECL
-VOID
-BlCreateStack(IN PVOID *StackPtr,
-              IN ULONG StackSize,
-              IN PVOID Callback);
-
 XTCDECL
 VOID
 BlDbgPrint(IN PUINT16 Format,
@@ -137,10 +131,6 @@ XTCDECL
 EFI_STATUS
 BlGetMemoryMap(OUT PEFI_MEMORY_MAP MemoryMap);
 
-XTCDECL
-VOID
-BlGetStackPointer(OUT PVOID *Stack);
-
 XTCDECL
 EFI_STATUS
 BlGetVirtualAddress(IN PLIST_ENTRY MemoryMappings,
@@ -185,10 +175,6 @@ XTCDECL
 EFI_STATUS
 BlRegisterXtLoaderProtocol();
 
-XTCDECL
-EFI_STATUS
-BlStartNewStack();
-
 XTCDECL
 EFI_STATUS
 BlStartXtLoader(IN EFI_HANDLE ImageHandle,

xtldr/xtldr.c

@@ -28,23 +28,6 @@ PVOID EfiLoaderStack;
 CPPORT EfiSerialPort;
 
 
-/**
- * Gets a pointer to the stack address.
- *
- * @param Stack
- *        Supplies a pointer to the memory area where address to the current stack will be stored.
- *
- * @return This routine does not return any value.
- *
- * @since XT 1.0
- */
-XTCDECL
-VOID
-BlGetStackPointer(OUT PVOID *Stack)
-{
-    *Stack = EfiLoaderStack;
-}
-
 /**
  * This routine loads XTLDR EFI modules.
  *
@@ -351,7 +334,6 @@ BlRegisterXtLoaderProtocol()
     EfiLdrProtocol.GetVirtualAddress = BlGetVirtualAddress;
     EfiLdrProtocol.InitializeVirtualMemory = BlInitializeVirtualMemory;
     EfiLdrProtocol.MapVirtualMemory = BlMapVirtualMemory;
-    EfiLdrProtocol.GetStack = BlGetStackPointer;
     EfiLdrProtocol.DbgPrint = BlDbgPrint;
     EfiLdrProtocol.EfiPrint = BlEfiPrint;
     EfiLdrProtocol.CloseVolume = BlCloseVolume;
@@ -363,39 +345,6 @@ BlRegisterXtLoaderProtocol()
                                                                   &EfiLdrProtocol);
 }
 
-/**
- * Callback routine called right after new stack is created.
- *
- * @return This routine returns a status code.
- *
- * @since XT 1.0
- */
-XTCDECL
-EFI_STATUS
-BlStartNewStack()
-{
-    EFI_STATUS Status;
-
-    /* Boot XTOS */
-    Status = BlLoadXtSystem();
-    if(Status != STATUS_EFI_SUCCESS)
-    {
-        /* Boot process failed */
-        BlEfiPrint(L"Failed to start XT OS (Status code: %lx)!\n", Status);
-    }
-
-    /* Infinite bootloader loop */
-    BlEfiPrint(L"System halted!");
-    for(;;)
-    {
-        HlClearInterruptFlag();
-        HlHalt();
-    }
-
-    /* Return success */
-    return STATUS_EFI_SUCCESS;
-}
-
 /**
  * This routine is the entry point of the XT EFI boot loader.
  *
@@ -469,11 +418,15 @@ BlStartXtLoader(IN EFI_HANDLE ImageHandle,
     /* Discover and enumerate EFI block devices */
     BlEnumerateEfiBlockDevices();
 
-    /* Create new bootloader stack */
+    /* Boot XTOS */
-    BlCreateStack(&EfiLoaderStack, KERNEL_STACK_SIZE, &BlStartNewStack);
+    Status = BlLoadXtSystem();
+    if(Status != STATUS_EFI_SUCCESS)
+    {
+        /* Boot process failed */
+        BlEfiPrint(L"Failed to start XT OS (Status code: %lx)!\n", Status);
+    }
 
     /* Infinite bootloader loop */
-    BlDbgPrint(L"ERROR: Unexpected exception occurred, probably did not create a new stack\n");
     BlEfiPrint(L"System halted!");
     for(;;)
     {