MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c

   1 /*++
   2
   3 Copyright (c) 2006, Intel Corporation
   4 All rights reserved. This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 Module Name:
  13
  14   DxeLoadFunc.c
  15
  16 Abstract:
  17
  18   Ia32-specifc functionality for DxeLoad.
  19
  20 --*/
  21
  22 #include "DxeIpl.h"
  23 #include "VirtualMemory.h"
  24
  25 //
  26 // Global Descriptor Table (GDT)
  27 //
  28 GLOBAL_REMOVE_IF_UNREFERENCED IA32_GDT gGdtEntries [] = {
  29 /* selector { Global Segment Descriptor                              } */
  30 /* 0x00 */  {{0,      0,  0,  0,    0,  0,  0,  0,    0,  0, 0,  0,  0}}, //null descriptor
  31 /* 0x08 */  {{0xffff, 0,  0,  0x2,  1,  0,  1,  0xf,  0,  0, 1,  1,  0}}, //linear data segment descriptor
  32 /* 0x10 */  {{0xffff, 0,  0,  0xf,  1,  0,  1,  0xf,  0,  0, 1,  1,  0}}, //linear code segment descriptor
  33 /* 0x18 */  {{0xffff, 0,  0,  0x3,  1,  0,  1,  0xf,  0,  0, 1,  1,  0}}, //system data segment descriptor
  34 /* 0x20 */  {{0xffff, 0,  0,  0xa,  1,  0,  1,  0xf,  0,  0, 1,  1,  0}}, //system code segment descriptor
  35 /* 0x28 */  {{0,      0,  0,  0,    0,  0,  0,  0,    0,  0, 0,  0,  0}}, //spare segment descriptor
  36 /* 0x30 */  {{0xffff, 0,  0,  0x2,  1,  0,  1,  0xf,  0,  0, 1,  1,  0}}, //system data segment descriptor
  37 /* 0x38 */  {{0xffff, 0,  0,  0xa,  1,  0,  1,  0xf,  0,  1, 0,  1,  0}}, //system code segment descriptor
  38 /* 0x40 */  {{0,      0,  0,  0,    0,  0,  0,  0,    0,  0, 0,  0,  0}}, //spare segment descriptor
  39 };
  40
  41 //
  42 // IA32 Gdt register
  43 //
  44 GLOBAL_REMOVE_IF_UNREFERENCED CONST IA32_DESCRIPTOR gGdt = {
  45   sizeof (gGdtEntries) - 1,
  46   (UINTN) gGdtEntries
  47   };
  48
  49 VOID
  50 HandOffToDxeCore (
  51   IN EFI_PHYSICAL_ADDRESS   DxeCoreEntryPoint,
  52   IN EFI_PEI_HOB_POINTERS   HobList,
  53   IN EFI_PEI_PPI_DESCRIPTOR *EndOfPeiSignal
  54   )
  55 {
  56   EFI_STATUS                Status;
  57   EFI_PHYSICAL_ADDRESS      BaseOfStack;
  58   EFI_PHYSICAL_ADDRESS      TopOfStack;
  59   UINTN                     PageTables;
  60
  61   Status = PeiServicesAllocatePages (EfiBootServicesData, EFI_SIZE_TO_PAGES (STACK_SIZE), &BaseOfStack);
  62   ASSERT_EFI_ERROR (Status);
  63
  64   if (FeaturePcdGet(PcdDxeIplSwitchToLongMode)) {
  65     //
  66     // Compute the top of the stack we were allocated, which is used to load X64 dxe core.
  67     // Pre-allocate a 32 bytes which confroms to x64 calling convention.
  68     //
  69     // The first four parameters to a function are passed in rcx, rdx, r8 and r9.
  70     // Any further parameters are pushed on the stack. Furthermore, space (4 * 8bytes) for the
  71     // register parameters is reserved on the stack, in case the called function
  72     // wants to spill them; this is important if the function is variadic.
  73     //
  74     TopOfStack = BaseOfStack + EFI_SIZE_TO_PAGES (STACK_SIZE) * EFI_PAGE_SIZE - 32;
  75
  76     //
  77     //  X64 Calling Conventions requires that the stack must be aligned to 16 bytes
  78     //
  79     TopOfStack = (EFI_PHYSICAL_ADDRESS) (UINTN) ALIGN_POINTER (TopOfStack, 16);
  80
  81     //
  82     // Load the GDT of Go64. Since the GDT of 32-bit Tiano locates in the BS_DATA
  83     // memory, it may be corrupted when copying FV to high-end memory
  84     //
  85     AsmWriteGdtr (&gGdt);
  86     //
  87     // Create page table and save PageMapLevel4 to CR3
  88     //
  89     PageTables = CreateIdentityMappingPageTables ();
  90
  91     //
  92     // End of PEI phase singal
  93     //
  94     Status = PeiServicesInstallPpi (EndOfPeiSignal);
  95     ASSERT_EFI_ERROR (Status);
  96
  97     AsmWriteCr3 (PageTables);
  98      //
  99     // Go to Long Mode. Interrupts will not get turned on until the CPU AP is loaded.
 100     // Call x64 drivers passing in single argument, a pointer to the HOBs.
 101     //
 102     AsmEnablePaging64 (
 103       SYS_CODE64_SEL,
 104       DxeCoreEntryPoint,
 105       (EFI_PHYSICAL_ADDRESS)(UINTN)(HobList.Raw),
 106       0,
 107       TopOfStack
 108       );
 109   } else {
 110     //
 111     // Compute the top of the stack we were allocated. Pre-allocate a UINTN
 112     // for safety.
 113     //
 114     TopOfStack = BaseOfStack + EFI_SIZE_TO_PAGES (STACK_SIZE) * EFI_PAGE_SIZE - CPU_STACK_ALIGNMENT;
 115     TopOfStack = (EFI_PHYSICAL_ADDRESS) (UINTN) ALIGN_POINTER (TopOfStack, CPU_STACK_ALIGNMENT);
 116
 117     //
 118     // End of PEI phase singal
 119     //
 120     Status = PeiServicesInstallPpi (EndOfPeiSignal);
 121     ASSERT_EFI_ERROR (Status);
 122
 123     SwitchStack (
 124       (SWITCH_STACK_ENTRY_POINT)(UINTN)DxeCoreEntryPoint,
 125       HobList.Raw,
 126       NULL,
 127       (VOID *) (UINTN) TopOfStack
 128       );
 129   }
 130 }
 131