Adding files from OvmfPkg to common location. This is so multiple packages can use...

[mirror_edk2.git] / UefiCpuPkg / ResetVector / Vtf0 / Ia16 / 16RealTo32Flat.asm

diff --git a/UefiCpuPkg/ResetVector/Vtf0/Ia16/16RealTo32Flat.asm b/UefiCpuPkg/ResetVector/Vtf0/Ia16/16RealTo32Flat.asm
new file mode 100644 (file)
index 0000000..3139ff5
--- /dev/null
+++ b/UefiCpuPkg/ResetVector/Vtf0/Ia16/16RealTo32Flat.asm
@@ -0,0 +1,133 @@
+;------------------------------------------------------------------------------\r
+; @file\r
+; Transition from 16 bit real mode into 32 bit flat protected mode\r
+;\r
+; Copyright (c) 2008 - 2010, Intel Corporation\r
+; All rights reserved. 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 SEC_DEFAULT_CR0  0x40000023\r
+%define SEC_DEFAULT_CR4  0x640\r
+\r
+BITS    16\r
+\r
+;\r
+; Modified:  EAX, EBX\r
+;\r
+TransitionFromReal16To32BitFlat:\r
+\r
+    debugShowPostCode POSTCODE_16BIT_MODE\r
+\r
+    cli\r
+\r
+    mov     bx, 0xf000\r
+    mov     ds, bx\r
+\r
+    mov     bx, ADDR16_OF(gdtr)\r
+\r
+o32 lgdt    [cs:bx]\r
+\r
+    mov     eax, SEC_DEFAULT_CR0\r
+    mov     cr0, eax\r
+\r
+    jmp     LINEAR_CODE_SEL:dword ADDR_OF(jumpTo32BitAndLandHere)\r
+BITS    32\r
+jumpTo32BitAndLandHere:\r
+\r
+    mov     eax, SEC_DEFAULT_CR4\r
+    mov     cr4, eax\r
+\r
+    debugShowPostCode POSTCODE_32BIT_MODE\r
+\r
+    mov     ax, LINEAR_SEL\r
+    mov     ds, ax\r
+    mov     es, ax\r
+    mov     fs, ax\r
+    mov     gs, ax\r
+    mov     ss, ax\r
+\r
+    OneTimeCallRet TransitionFromReal16To32BitFlat\r
+\r
+ALIGN   2\r
+\r
+gdtr:\r
+    dw      GDT_END - GDT_BASE - 1   ; GDT limit\r
+    dd      ADDR_OF(GDT_BASE)\r
+\r
+ALIGN   16\r
+\r
+;\r
+; Macros for GDT entries\r
+;\r
+\r
+%define  PRESENT_FLAG(p) (p << 7)\r
+%define  DPL(dpl) (dpl << 5)\r
+%define  SYSTEM_FLAG(s) (s << 4)\r
+%define  DESC_TYPE(t) (t)\r
+\r
+; Type: data, expand-up, writable, accessed\r
+%define  DATA32_TYPE 3\r
+\r
+; Type: execute, readable, expand-up, accessed\r
+%define  CODE32_TYPE 0xb\r
+\r
+; Type: execute, readable, expand-up, accessed\r
+%define  CODE64_TYPE 0xb\r
+\r
+%define  GRANULARITY_FLAG(g) (g << 7)\r
+%define  DEFAULT_SIZE32(d) (d << 6)\r
+%define  CODE64_FLAG(l) (l << 5)\r
+%define  UPPER_LIMIT(l) (l)\r
+\r
+;\r
+; The Global Descriptor Table (GDT)\r
+;\r
+\r
+GDT_BASE:\r
+; null descriptor\r
+NULL_SEL            equ $-GDT_BASE\r
+    DW      0            ; limit 15:0\r
+    DW      0            ; base 15:0\r
+    DB      0            ; base 23:16\r
+    DB      0            ; sys flag, dpl, type\r
+    DB      0            ; limit 19:16, flags\r
+    DB      0            ; base 31:24\r
+\r
+; linear data segment descriptor\r
+LINEAR_SEL          equ $-GDT_BASE\r
+    DW      0xffff       ; limit 15:0\r
+    DW      0            ; base 15:0\r
+    DB      0            ; base 23:16\r
+    DB      PRESENT_FLAG(1)|DPL(0)|SYSTEM_FLAG(1)|DESC_TYPE(DATA32_TYPE)\r
+    DB      GRANULARITY_FLAG(1)|DEFAULT_SIZE32(1)|CODE64_FLAG(0)|UPPER_LIMIT(0xf)\r
+    DB      0            ; base 31:24\r
+\r
+; linear code segment descriptor\r
+LINEAR_CODE_SEL     equ $-GDT_BASE\r
+    DW      0xffff       ; limit 15:0\r
+    DW      0            ; base 15:0\r
+    DB      0            ; base 23:16\r
+    DB      PRESENT_FLAG(1)|DPL(0)|SYSTEM_FLAG(1)|DESC_TYPE(CODE32_TYPE)\r
+    DB      GRANULARITY_FLAG(1)|DEFAULT_SIZE32(1)|CODE64_FLAG(0)|UPPER_LIMIT(0xf)\r
+    DB      0            ; base 31:24\r
+\r
+%ifdef ARCH_X64\r
+; linear code (64-bit) segment descriptor\r
+LINEAR_CODE64_SEL   equ $-GDT_BASE\r
+    DW      0xffff       ; limit 15:0\r
+    DW      0            ; base 15:0\r
+    DB      0            ; base 23:16\r
+    DB      PRESENT_FLAG(1)|DPL(0)|SYSTEM_FLAG(1)|DESC_TYPE(CODE64_TYPE)\r
+    DB      GRANULARITY_FLAG(1)|DEFAULT_SIZE32(0)|CODE64_FLAG(1)|UPPER_LIMIT(0xf)\r
+    DB      0            ; base 31:24\r
+%endif\r
+\r
+GDT_END:\r
+\r