Add GCC assember for DxeIpl module

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@7395 6f19259b-4bc3-4df7-8a09-765794883524

DuetPkg/DxeIpl/Ia32/CpuIoAccessGnu.c

@@ -0,0 +1,27 @@
+UINT8
+EFIAPI
+CpuIoRead8 (
+  IN  UINT16  Port
+  )
+{
+  UINT8     Data;
+  asm ( "inb %1, %0"
+      : "=a"(Data)
+      : "d"(Port)
+      );
+  return Data;
+}
+
+VOID
+EFIAPI
+CpuIoWrite8 (
+  IN  UINT16  Port,
+  IN  UINT32  Data
+  )
+{
+  asm ( "outb %1, %0"
+      : /* No outputs */
+      : "d"(Port)
+      , "a"((UINT8)Data)
+      );
+}

DuetPkg/DxeIpl/Ia32/EnterDxeCoreGnu.c

@@ -0,0 +1,16 @@
+VOID
+EnterDxeMain (
+  IN VOID *StackTop,
+  IN VOID *DxeCoreEntryPoint,
+  IN VOID *Hob,
+  IN VOID *PageTable
+  )
+{
+  __asm__ ( "movl  %0, %%esp \n\t"
+            "pushl %2 \n\t"
+            "pushl $0 \n\t"
+            "movl  %1, %%ecx \n\t"
+            "jmp  %%ecx"
+            ::"q"(StackTop), "q"(DxeCoreEntryPoint), "q"(Hob)
+          );
+}