reactos/boot/freeldr/freeldr/arch/i386/loader.c

   1 /*
   2  *  FreeLoader
   3  *  Copyright (C) 1998-2003  Brian Palmer  <brianp@sginet.com>
   4  *  Copyright (C) 2005       Alex Ionescu  <alex@relsoft.net>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  */
  20 #define _NTSYSTEM_
  21 #include <freeldr.h>
  22
  23 #define NDEBUG
  24 #include <debug.h>
  25 #undef DbgPrint
  26
  27 /* Page Directory and Tables for non-PAE Systems */
  28 extern PAGE_DIRECTORY_X86 startup_pagedirectory;
  29 extern PAGE_DIRECTORY_X86 lowmem_pagetable;
  30 extern PAGE_DIRECTORY_X86 kernel_pagetable;
  31 extern PAGE_DIRECTORY_X86 hyperspace_pagetable;
  32 extern PAGE_DIRECTORY_X86 apic_pagetable;
  33 extern PAGE_DIRECTORY_X86 kpcr_pagetable;
  34 extern PAGE_DIRECTORY_X86 kuser_pagetable;
  35 extern ULONG_PTR KernelBase;
  36 extern ROS_KERNEL_ENTRY_POINT KernelEntryPoint;
  37 /* FUNCTIONS *****************************************************************/
  38
  39 /*++
  40  * FrLdrStartup
  41  * INTERNAL
  42  *
  43  *     Prepares the system for loading the Kernel.
  44  *
  45  * Params:
  46  *     Magic - Multiboot Magic
  47  *
  48  * Returns:
  49  *     None.
  50  *
  51  * Remarks:
  52  *     None.
  53  *
  54  *--*/
  55 VOID
  56 NTAPI
  57 FrLdrStartup(ULONG Magic)
  58 {
  59     /* Disable Interrupts */
  60     _disable();
  61
  62     /* Re-initalize EFLAGS */
  63     Ke386EraseFlags();
  64
  65     /* Initialize the page directory */
  66     FrLdrSetupPageDirectory();
  67
  68     /* Initialize Paging, Write-Protection and Load NTOSKRNL */
  69     FrLdrSetupPae(Magic);
  70 }
  71
  72 /*++
  73  * FrLdrSetupPae
  74  * INTERNAL
  75  *
  76  *     Configures PAE on a MP System, and sets the PDBR if it's supported, or if
  77  *     the system is UP.
  78  *
  79  * Params:
  80  *     Magic - Multiboot Magic
  81  *
  82  * Returns:
  83  *     None.
  84  *
  85  * Remarks:
  86  *     None.
  87  *
  88  *--*/
  89 VOID
  90 FASTCALL
  91 FrLdrSetupPae(ULONG Magic)
  92 {
  93     ULONG_PTR PageDirectoryBaseAddress = (ULONG_PTR)&startup_pagedirectory;
  94
  95     /* Set the PDBR */
  96     __writecr3(PageDirectoryBaseAddress);
  97
  98     /* Enable Paging and Write Protect*/
  99     __writecr0(__readcr0() | CR0_PG | CR0_WP);
 100
 101     /* Jump to Kernel */
 102     (*KernelEntryPoint)(Magic, &LoaderBlock);
 103 }
 104
 105 /*++
 106  * FrLdrSetupPageDirectory
 107  * INTERNAL
 108  *
 109  *     Sets up the ReactOS Startup Page Directory.
 110  *
 111  * Params:
 112  *     None.
 113  *
 114  * Returns:
 115  *     None.
 116  *
 117  * Remarks:
 118  *     We are setting PDEs, but using the equvivalent (for our purpose) PTE structure.
 119  *     As such, please note that PageFrameNumber == PageEntryNumber.
 120  *
 121  *--*/
 122 VOID
 123 FASTCALL
 124 FrLdrSetupPageDirectory(VOID)
 125 {
 126     PPAGE_DIRECTORY_X86 PageDir;
 127     ULONG KernelPageTableIndex;
 128     ULONG i;
 129
 130     /* Get the Kernel Table Index */
 131     KernelPageTableIndex = KernelBase >> PDE_SHIFT;
 132
 133     /* Get the Startup Page Directory */
 134     PageDir = (PPAGE_DIRECTORY_X86)&startup_pagedirectory;
 135
 136     /* Set up the Low Memory PDE */
 137     PageDir->Pde[LowMemPageTableIndex].Valid = 1;
 138     PageDir->Pde[LowMemPageTableIndex].Write = 1;
 139     PageDir->Pde[LowMemPageTableIndex].PageFrameNumber = PaPtrToPfn(lowmem_pagetable);
 140
 141     /* Set up the Kernel PDEs */
 142     PageDir->Pde[KernelPageTableIndex].Valid = 1;
 143     PageDir->Pde[KernelPageTableIndex].Write = 1;
 144     PageDir->Pde[KernelPageTableIndex].PageFrameNumber = PaPtrToPfn(kernel_pagetable);
 145     PageDir->Pde[KernelPageTableIndex + 1].Valid = 1;
 146     PageDir->Pde[KernelPageTableIndex + 1].Write = 1;
 147     PageDir->Pde[KernelPageTableIndex + 1].PageFrameNumber = PaPtrToPfn(kernel_pagetable + 4096);
 148
 149     /* Set up the Startup PDE */
 150     PageDir->Pde[StartupPageTableIndex].Valid = 1;
 151     PageDir->Pde[StartupPageTableIndex].Write = 1;
 152     PageDir->Pde[StartupPageTableIndex].PageFrameNumber = PaPtrToPfn(startup_pagedirectory);
 153
 154     /* Set up the Hyperspace PDE */
 155     PageDir->Pde[HyperspacePageTableIndex].Valid = 1;
 156     PageDir->Pde[HyperspacePageTableIndex].Write = 1;
 157     PageDir->Pde[HyperspacePageTableIndex].PageFrameNumber = PaPtrToPfn(hyperspace_pagetable);
 158
 159     /* Set up the HAL PDE */
 160     PageDir->Pde[HalPageTableIndex].Valid = 1;
 161     PageDir->Pde[HalPageTableIndex].Write = 1;
 162     PageDir->Pde[HalPageTableIndex].PageFrameNumber = PaPtrToPfn(apic_pagetable);
 163
 164     /* Set up Low Memory PTEs */
 165     PageDir = (PPAGE_DIRECTORY_X86)&lowmem_pagetable;
 166     for (i=0; i<1024; i++)
 167     {
 168         PageDir->Pde[i].Valid = 1;
 169         PageDir->Pde[i].Write = 1;
 170         PageDir->Pde[i].Owner = 1;
 171         PageDir->Pde[i].PageFrameNumber = PaToPfn(i * PAGE_SIZE);
 172     }
 173
 174     /* Set up Kernel PTEs */
 175     PageDir = (PPAGE_DIRECTORY_X86)&kernel_pagetable;
 176     for (i=0; i<1536; i++)
 177     {
 178         PageDir->Pde[i].Valid = 1;
 179         PageDir->Pde[i].Write = 1;
 180         PageDir->Pde[i].PageFrameNumber = PaToPfn(KERNEL_BASE_PHYS + i * PAGE_SIZE);
 181     }
 182
 183     /* Setup APIC Base */
 184     PageDir = (PPAGE_DIRECTORY_X86)&apic_pagetable;
 185     PageDir->Pde[0].Valid = 1;
 186     PageDir->Pde[0].Write = 1;
 187     PageDir->Pde[0].CacheDisable = 1;
 188     PageDir->Pde[0].WriteThrough = 1;
 189     PageDir->Pde[0].PageFrameNumber = PaToPfn(HAL_BASE);
 190     PageDir->Pde[0x200].Valid = 1;
 191     PageDir->Pde[0x200].Write = 1;
 192     PageDir->Pde[0x200].CacheDisable = 1;
 193     PageDir->Pde[0x200].WriteThrough = 1;
 194     PageDir->Pde[0x200].PageFrameNumber = PaToPfn(HAL_BASE + KERNEL_BASE_PHYS);
 195
 196     /* Setup KUSER_SHARED_DATA Base */
 197     PageDir->Pde[0x1F0].Valid = 1;
 198     PageDir->Pde[0x1F0].Write = 1;
 199     PageDir->Pde[0x1F0].PageFrameNumber = 2;
 200
 201     /* Setup KPCR Base*/
 202     PageDir->Pde[0x1FF].Valid = 1;
 203     PageDir->Pde[0x1FF].Write = 1;
 204     PageDir->Pde[0x1FF].PageFrameNumber = 1;
 205
 206     /* Zero shared data */
 207     RtlZeroMemory((PVOID)(2 << MM_PAGE_SHIFT), PAGE_SIZE);
 208 }
 209