Common routines for reading from and writing to CPU control registers

sdk/xtdk/amd64/hlfuncs.h

@@ -37,42 +37,11 @@ HlIoPortOutByte(IN USHORT Port,
 
 XTAPI
 ULONG_PTR
-HlReadCR0();
+HlReadControlRegister(USHORT ControlRegister);
-
-XTAPI
-ULONG_PTR
-HlReadCR2();
-
-XTAPI
-ULONG_PTR
-HlReadCR3();
-
-XTAPI
-ULONG_PTR
-HlReadCR4();
-
-XTAPI
-ULONG_PTR
-HlReadCR8();
 
 XTAPI
 VOID
-HlWriteCR0(UINT_PTR Data);
+HlWriteControlRegister(USHORT ControlRegister,
-
+                       UINT_PTR Value);
-XTAPI
-VOID
-HlWriteCR2(UINT_PTR Data);
-
-XTAPI
-VOID
-HlWriteCR3(UINT_PTR Data);
-
-XTAPI
-VOID
-HlWriteCR4(UINT_PTR Data);
-
-XTAPI
-VOID
-HlWriteCR8(UINT_PTR Data);
 
 #endif /* __XTDK_AMD64_HLFUNCS_H */

sdk/xtdk/i686/hlfuncs.h

@@ -37,34 +37,11 @@ HlIoPortOutByte(IN USHORT Port,
 
 XTAPI
 ULONG_PTR
-HlReadCR0();
+HlReadControlRegister(USHORT ControlRegister);
-
-XTAPI
-ULONG_PTR
-HlReadCR2();
-
-XTAPI
-ULONG_PTR
-HlReadCR3();
-
-XTAPI
-ULONG_PTR
-HlReadCR4();
 
 XTAPI
 VOID
-HlWriteCR0(IN UINT_PTR Data);
+HlWriteControlRegister(USHORT ControlRegister,
-
+                       UINT_PTR Value);
-XTAPI
-VOID
-HlWriteCR2(IN UINT_PTR Data);
-
-XTAPI
-VOID
-HlWriteCR3(IN UINT_PTR Data);
-
-XTAPI
-VOID
-HlWriteCR4(IN UINT_PTR Data);
 
 #endif /* __XTDK_I686_HLFUNCS_H */

xtldr/amd64/memory.c

@@ -168,7 +168,7 @@ BlEnablePaging(IN PLIST_ENTRY MemoryMappings,
                                                           MemoryMap->DescriptorVersion, MemoryMap->Map);
 
     /* Write PML4 to CR3 */
-    HlWriteCR3((UINT_PTR)*PtePointer);
+    HlWriteControlRegister(3, (UINT_PTR)*PtePointer);
 
     /* Return success */
     return STATUS_EFI_SUCCESS;

xtldr/i686/memory.c

@@ -170,7 +170,7 @@ BlEnablePaging(IN PLIST_ENTRY MemoryMappings,
         VirtualAddress = (PVOID)(UINT_PTR)(PDPTAddress + EFI_PAGE_SIZE + KSEG0_BASE);
 
         /* Set base page frame number */
-        Address = 0x100000; // MEM_TOP_DOWN ?
+        Address = 0x100000;
 
         /* Allocate pages for the PFN */
         Status = BlEfiMemoryAllocatePages(4, &Address);
@@ -278,14 +278,14 @@ BlEnablePaging(IN PLIST_ENTRY MemoryMappings,
     if(PaeExtension)
     {
         /* Enable Physical Address Extension (PAE) */
-        HlWriteCR4(HlReadCR4() | 0x00000020);
+        HlWriteControlRegister(4, HlReadControlRegister(4) | 0x00000020);
     }
 
     /* Write page mappings to CR3 */
-    HlWriteCR3((UINT_PTR)*PtePointer);
+    HlWriteControlRegister(3, (UINT_PTR)*PtePointer);
 
     /* Enable paging */
-    HlWriteCR0(HlReadCR0() | 0x80000000);
+    HlWriteControlRegister(0, HlReadControlRegister(0) | 0x80000000);
 
     /* Return success */
     return STATUS_EFI_SUCCESS;

xtoskrnl/hl/amd64/cpufunc.c

@@ -114,105 +114,76 @@ HlIoPortOutByte(IN USHORT Port,
 }
 
 /**
- * Reads the CR0 register and returns its value.
+ * Reads the specified CPU control register and returns its value.
  *
- * @return The value stored in the CR0 register.
+ * @param ControlRegister
+ *        Supplies a number of a control register which controls the general behavior of a CPU.
+ *
+ * @return The value stored in the control register.
  *
  * @since XT 1.0
  */
 XTAPI
 ULONG_PTR
-HlReadCR0()
+HlReadControlRegister(USHORT ControlRegister)
 {
     ULONG_PTR Value;
+
+    /* Read a value from specified CR register */
+    switch(ControlRegister)
+    {
+        case 0:
+            /* Read value from CR0 */
             asm volatile("mov %%cr0, %0"
                          : "=r" (Value)
                          :
                          : "memory");
-    return Value;
+            break;
-}
+        case 2:
-
+            /* Read value from CR2 */
-/**
- * Reads the CR2 register and returns its value.
- *
- * @return The value stored in the CR2 register.
- *
- * @since XT 1.0
- */
-XTAPI
-ULONG_PTR
-HlReadCR2()
-{
-    ULONG_PTR Value;
             asm volatile("mov %%cr2, %0"
                          : "=r" (Value)
                          :
                          : "memory");
-    return Value;
+            break;
-}
+        case 3:
-
+            /* Read value from CR3 */
-/**
- * Reads the CR3 register and returns its value.
- *
- * @return The value stored in the CR3 register.
- *
- * @since XT 1.0
- */
-XTAPI
-ULONG_PTR
-HlReadCR3()
-{
-    ULONG_PTR Value;
             asm volatile("mov %%cr3, %0"
                          : "=r" (Value)
                          :
                          : "memory");
-    return Value;
+            break;
-}
+        case 4:
-
+            /* Read value from CR4 */
-/**
- * Reads the CR4 register and returns its value.
- *
- * @return The value stored in the CR4 register.
- *
- * @since XT 1.0
- */
-XTAPI
-ULONG_PTR
-HlReadCR4()
-{
-    ULONG_PTR Value;
             asm volatile("mov %%cr4, %0"
                          : "=r" (Value)
                          :
                          : "memory");
-    return Value;
+            break;
-}
+        case 8:
-
+            /* Read value from CR8 */
-/**
- * Reads the CR8 register and returns its value.
- *
- * @return The value stored in the CR8 register.
- *
- * @since XT 1.0
- */
-XTAPI
-ULONG_PTR
-HlReadCR8()
-{
-    ULONG_PTR Value;
             asm volatile("mov %%cr8, %0"
                          : "=r" (Value)
                          :
                          : "memory");
+        default:
+            /* Invalid control register set */
+            Value = 0;
+            break;
+    }
+
+    /* Return value read from given CR register */
     return Value;
 }
 
 /**
- * Writes the value to the CR0 register.
+ * Writes a value to the specified CPU control register.
  *
- * @param Data
+ * @param ControlRegister
- *        The value to write to the CR0 register.
+ *        Supplies a number of a control register which controls the general behavior of a CPU.
+ *
+ * @param Value
+ *        Suplies a value to write to the CR register.
  *
  * @return This routine does not return any value.
  *
@@ -220,90 +191,46 @@ HlReadCR8()
  */
 XTAPI
 VOID
-HlWriteCR0(UINT_PTR Data)
+HlWriteControlRegister(USHORT ControlRegister,
+                       UINT_PTR Value)
 {
+    /* Write a value into specified control register */
+    switch(ControlRegister)
+    {
+        case 0:
+            /* Write value to CR0 */
             asm volatile("mov %0, %%cr0"
                          :
-                 : "r"(Data)
+                         : "r"(Value)
                          : "memory");
-}
+            break;
-
+        case 2:
-/**
+            /* Write value to CR2 */
- * Writes the value to the CR2 register.
- *
- * @param Data
- *        The value to write to the CR2 register.
- *
- * @return This routine does not return any value.
- *
- * @since XT 1.0
- */
-XTAPI
-VOID
-HlWriteCR2(UINT_PTR Data)
-{
             asm volatile("mov %0, %%cr2"
                          :
-                 : "r"(Data)
+                         : "r"(Value)
                          : "memory");
-}
+            break;
-
+        case 3:
-/**
+            /* Write value to CR3 */
- * Writes the value to the CR3 register.
- *
- * @param Data
- *        The value to write to the CR3 register.
- *
- * @return This routine does not return any value.
- *
- * @since XT 1.0
- */
-XTAPI
-VOID
-HlWriteCR3(UINT_PTR Data)
-{
             asm volatile("mov %0, %%cr3"
                          :
-                 : "r"(Data)
+                         : "r"(Value)
                          : "memory");
-}
+            break;
-
+        case 4:
-/**
+            /* Write value to CR4 */
- * Writes the value to the CR4 register.
- *
- * @param Data
- *        The value to write to the CR4 register.
- *
- * @return This routine does not return any value.
- *
- * @since XT 1.0
- */
-XTAPI
-VOID
-HlWriteCR4(UINT_PTR Data)
-{
             asm volatile("mov %0, %%cr4"
                          :
-                 : "r"(Data)
+                         : "r"(Value)
                          : "memory");
-}
+            break;
-
+        case 8:
-/**
+            /* Write value to CR8 */
- * Writes the value to the CR8 register.
- *
- * @param Data
- *        The value to write to the CR8 register.
- *
- * @return This routine does not return any value.
- *
- * @since XT 1.0
- */
-XTAPI
-VOID
-HlWriteCR8(UINT_PTR Data)
-{
             asm volatile("mov %0, %%cr8"
                          :
-                 : "r"(Data)
+                         : "r"(Value)
                          : "memory");
+            break;
+    }
 }

xtoskrnl/hl/i686/cpufunc.c

@@ -114,86 +114,70 @@ HlIoPortOutByte(IN USHORT Port,
 }
 
 /**
- * Reads the CR0 register and returns its value.
+ * Reads the specified CPU control register and returns its value.
  *
- * @return The value stored in the CR0 register.
+ * @param ControlRegister
+ *        Supplies a number of a control register which controls the general behavior of a CPU.
+ *
+ * @return The value stored in the control register.
  *
  * @since XT 1.0
  */
 XTAPI
 ULONG_PTR
-HlReadCR0()
+HlReadControlRegister(USHORT ControlRegister)
 {
     ULONG_PTR Value;
+
+    /* Read a value from specified CR register */
+    switch(ControlRegister)
+    {
+        case 0:
+            /* Read value from CR0 */
             asm volatile("mov %%cr0, %0"
                          : "=r" (Value)
                          :
                          : "memory");
-    return Value;
+            break;
-}
+        case 2:
-
+            /* Read value from CR2 */
-/**
- * Reads the CR2 register and returns its value.
- *
- * @return The value stored in the CR2 register.
- *
- * @since XT 1.0
- */
-XTAPI
-ULONG_PTR
-HlReadCR2()
-{
-    ULONG_PTR Value;
             asm volatile("mov %%cr2, %0"
                          : "=r" (Value)
                          :
                          : "memory");
-    return Value;
+            break;
-}
+        case 3:
-
+            /* Read value from CR3 */
-/**
- * Reads the CR3 register and returns its value.
- *
- * @return The value stored in the CR3 register.
- *
- * @since XT 1.0
- */
-XTAPI
-ULONG_PTR
-HlReadCR3()
-{
-    ULONG_PTR Value;
             asm volatile("mov %%cr3, %0"
                          : "=r" (Value)
                          :
                          : "memory");
-    return Value;
+            break;
-}
+        case 4:
-
+            /* Read value from CR4 */
-/**
- * Reads the CR4 register and returns its value.
- *
- * @return The value stored in the CR4 register.
- *
- * @since XT 1.0
- */
-XTAPI
-ULONG_PTR
-HlReadCR4()
-{
-    ULONG_PTR Value;
             asm volatile("mov %%cr4, %0"
                          : "=r" (Value)
                          :
                          : "memory");
+            break;
+        default:
+            /* Invalid control register set */
+            Value = 0;
+            break;
+    }
+
+    /* Return value read from given CR register */
     return Value;
 }
 
 /**
- * Writes the value to the CR0 register.
+ * Writes a value to the specified CPU control register.
  *
- * @param Data
+ * @param ControlRegister
- *        The value to write to the CR0 register.
+ *        Supplies a number of a control register which controls the general behavior of a CPU.
+ *
+ * @param Value
+ *        Suplies a value to write to the CR register.
  *
  * @return This routine does not return any value.
  *
@@ -201,70 +185,39 @@ HlReadCR4()
  */
 XTAPI
 VOID
-HlWriteCR0(UINT_PTR Data)
+HlWriteControlRegister(USHORT ControlRegister,
+                       UINT_PTR Value)
 {
+    /* Write a value into specified control register */
+    switch(ControlRegister)
+    {
+        case 0:
+            /* Write value to CR0 */
             asm volatile("mov %0, %%cr0"
                          :
-                 : "r"(Data)
+                         : "r"(Value)
                          : "memory");
-}
+            break;
-
+        case 2:
-/**
+            /* Write value to CR2 */
- * Writes the value to the CR2 register.
- *
- * @param Data
- *        The value to write to the CR2 register.
- *
- * @return This routine does not return any value.
- *
- * @since XT 1.0
- */
-XTAPI
-VOID
-HlWriteCR2(UINT_PTR Data)
-{
             asm volatile("mov %0, %%cr2"
                          :
-                 : "r"(Data)
+                         : "r"(Value)
                          : "memory");
-}
+            break;
-
+        case 3:
-/**
+            /* Write value to CR3 */
- * Writes the value to the CR3 register.
- *
- * @param Data
- *        The value to write to the CR3 register.
- *
- * @return This routine does not return any value.
- *
- * @since XT 1.0
- */
-XTAPI
-VOID
-HlWriteCR3(UINT_PTR Data)
-{
             asm volatile("mov %0, %%cr3"
                          :
-                 : "r"(Data)
+                         : "r"(Value)
                          : "memory");
-}
+            break;
-
+        case 4:
-/**
+            /* Write value to CR4 */
- * Writes the value to the CR4 register.
- *
- * @param Data
- *        The value to write to the CR4 register.
- *
- * @return This routine does not return any value.
- *
- * @since XT 1.0
- */
-XTAPI
-VOID
-HlWriteCR4(UINT_PTR Data)
-{
             asm volatile("mov %0, %%cr4"
                          :
-                 : "r"(Data)
+                         : "r"(Value)
                          : "memory");
+            break;
+    }
 }