+;; @file\r
+; This is the code that goes from real-mode to protected mode.\r
+; It consumes the reset vector, configures the stack.\r
+;\r
+; Copyright (c) 2015 - 2016, Intel Corporation. All rights reserved.<BR>\r
+; This program and the accompanying materials\r
+; are licensed and made available under the terms and conditions of the BSD License\r
+; which accompanies this distribution. The full text of the license may be found at\r
+; http://opensource.org/licenses/bsd-license.php.\r
+;\r
+; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
+; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
+;;\r
+\r
+;\r
+; Define assembler characteristics\r
+;\r
+\r
+extern ASM_PFX(TempRamInitApi)\r
+\r
+SECTION .text\r
+\r
+%macro RET_ESI 0\r
+\r
+ movd esi, mm7 ; restore ESP from MM7\r
+ jmp esi\r
+\r
+%endmacro\r
+\r
+;\r
+; Perform early platform initialization\r
+;\r
+global ASM_PFX(SecPlatformInit)\r
+ASM_PFX(SecPlatformInit):\r
+\r
+ RET_ESI\r
+\r
+;\r
+; Protected mode portion initializes stack, configures cache, and calls C entry point\r
+;\r
+\r
+;----------------------------------------------------------------------------\r
+;\r
+; Procedure: ProtectedModeEntryPoint\r
+;\r
+; Input: Executing in 32 Bit Protected (flat) mode\r
+; cs: 0-4GB\r
+; ds: 0-4GB\r
+; es: 0-4GB\r
+; fs: 0-4GB\r
+; gs: 0-4GB\r
+; ss: 0-4GB\r
+;\r
+; Output: This function never returns\r
+;\r
+; Destroys:\r
+; ecx\r
+; edi\r
+; esi\r
+; esp\r
+;\r
+; Description:\r
+; Perform any essential early platform initilaisation\r
+; Setup a stack\r
+;\r
+;----------------------------------------------------------------------------\r
+global ASM_PFX(ProtectedModeEntryPoint)\r
+ASM_PFX(ProtectedModeEntryPoint):\r
+ ;\r
+ ; Dummy function. Consume 2 API to make sure they can be linked.\r
+ ;\r
+ mov eax, ASM_PFX(TempRamInitApi)\r
+\r
+ ; Should never return\r
+ jmp $\r
+\r
+;\r
+; ROM-based Global-Descriptor Table for the PEI Phase\r
+;\r
+align 16\r
+global ASM_PFX(BootGdtTable)\r
+\r
+;\r
+; GDT[0]: 0x00: Null entry, never used.\r
+;\r
+NULL_SEL equ $ - GDT_BASE ; Selector [0]\r
+GDT_BASE:\r
+ASM_PFX(BootGdtTable): DD 0\r
+ DD 0\r
+;\r
+; Linear code segment descriptor\r
+;\r
+LINEAR_CODE_SEL equ $ - GDT_BASE ; Selector [0x8]\r
+ DW 0FFFFh ; limit 0xFFFF\r
+ DW 0 ; base 0\r
+ DB 0\r
+ DB 09Bh ; present, ring 0, data, expand-up, not-writable\r
+ DB 0CFh ; page-granular, 32-bit\r
+ DB 0\r
+;\r
+; System data segment descriptor\r
+;\r
+SYS_DATA_SEL equ $ - GDT_BASE ; Selector [0x10]\r
+ DW 0FFFFh ; limit 0xFFFF\r
+ DW 0 ; base 0\r
+ DB 0\r
+ DB 093h ; present, ring 0, data, expand-up, not-writable\r
+ DB 0CFh ; page-granular, 32-bit\r
+ DB 0\r
+\r
+GDT_SIZE EQU $ - GDT_BASE ; Size, in bytes\r
+\r
+;\r
+; GDT Descriptor\r
+;\r
+GdtDesc: ; GDT descriptor\r
+ DW GDT_SIZE - 1 ; GDT limit\r
+ DD GDT_BASE ; GDT base address\r
+\r
+global ASM_PFX(ProtectedModeEntryLinearAddress)\r
+global ASM_PFX(ProtectedModeEntryLinearOffset)\r
+\r
+ASM_PFX(ProtectedModeEntryLinearAddress):\r
+ASM_PFX(ProtectedModeEntryLinearOffset):\r
+ DD ASM_PFX(ProtectedModeEntryPoint) ; Offset of our 32 bit code\r
+ DW LINEAR_CODE_SEL\r
+ \r