[mirror_edk2.git] / IntelFspPkg / Library / SecFspSecPlatformLibNull / Ia32 / Flat32.s

#------------------------------------------------------------------------------\r
#\r
# Copyright (c) 2015, 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
# Abstract:\r
#\r
#  This is the code that goes from real-mode to protected mode.\r
#  It consumes the reset vector, configures the stack.\r
#\r
#------------------------------------------------------------------------------\r
\r
\r
#\r
# Contrary to the name, this file contains 16 bit code as well.\r
#\r
.text\r
#----------------------------------------------------------------------------\r
#\r
# Procedure:    _ModuleEntryPoint\r
#\r
# Input:        None\r
#\r
# Output:       None\r
#\r
# Destroys:     Assume all registers\r
#\r
# Description:\r
#\r
#   Transition to non-paged flat-model protected mode from a\r
#   hard-coded GDT that provides exactly two descriptors.\r
#   This is a bare bones transition to protected mode only\r
#   used for a while in PEI and possibly DXE.\r
#\r
#   After enabling protected mode, a far jump is executed to\r
#   transfer to PEI using the newly loaded GDT.\r
#\r
# Return:       None\r
#\r
#----------------------------------------------------------------------------\r
ASM_GLOBAL ASM_PFX(_ModuleEntryPoint)\r
ASM_PFX(_ModuleEntryPoint):\r
\r
  #\r
  # Load the GDT table in GdtDesc\r
  #\r
  .byte   0x66,0xbe        #movl    $GdtDesc, %esi\r
  .long   GdtDesc\r
  \r
  .byte   0x66,0x2e,0x0f,0x01,0x14   #lgdt    %cs:(%si)\r
\r
  #\r
  # Transition to 16 bit protected mode\r
  #\r
  .byte   0x0f,0x20,0xc0       #movl    %cr0, %eax                  # Get control register 0\r
  .byte   0x66,0x83,0xc8,0x03  #orl     $0x0000003, %eax            # Set PE bit (bit #0) & MP bit (bit #1)\r
  .byte   0x0f,0x22,0xc0       #movl    %eax, %cr0                  # Activate protected mode\r
\r
  #\r
  # Now we're in 16 bit protected mode\r
  # Set up the selectors for 32 bit protected mode entry\r
  # \r
  .byte   0xb8                 #movw    SYS_DATA_SEL, %ax\r
  .word   SYS_DATA_SEL\r
  \r
  .byte   0x8e,0xd8            #movw    %ax, %ds\r
  .byte   0x8e,0xc0            #movw    %ax, %es\r
  .byte   0x8e,0xe0            #movw    %ax, %fs\r
  .byte   0x8e,0xe8            #movw    %ax, %gs\r
  .byte   0x8e,0xd0            #movw    %ax, %ss\r
\r
  #\r
  # Transition to Flat 32 bit protected mode\r
  # The jump to a far pointer causes the transition to 32 bit mode\r
  #\r
  .byte   0x66,0xbe            #movl   ProtectedModeEntryLinearAddress, %esi\r
  .long   ProtectedModeEntryLinearAddress \r
  .byte   0x66,0x2e,0xff,0x2c  #jmp    %cs:(%esi)\r
\r
#\r
# Protected mode portion initializes stack, configures cache, and calls C entry point\r
#\r
\r
#----------------------------------------------------------------------------\r
#\r
# Procedure:    ProtectedModeEntryPoint\r
#\r
# Input:        Executing in 32 Bit Protected (flat) mode\r
#               cs: 0-4GB\r
#               ds: 0-4GB\r
#               es: 0-4GB\r
#               fs: 0-4GB\r
#               gs: 0-4GB\r
#               ss: 0-4GB\r
#\r
# Output:       This function never returns\r
#\r
# Destroys:\r
#               ecx\r
#               edi\r
#               esi\r
#               esp\r
#\r
# Description:\r
#               Perform any essential early platform initilaisation\r
#               Setup a stack\r
#\r
#----------------------------------------------------------------------------\r
ProtectedModeEntryPoint:\r
  #\r
  # Dummy function. Consume 2 API to make sure they can be linked.\r
  #\r
  movl   ASM_PFX(TempRamInitApi), %eax\r
  movl   ASM_PFX(FspInitApi), %eax\r
  #\r
  # Should never return\r
  #\r
  jmp     . #'$'\r
\r
#\r
# ROM-based Global-Descriptor Table for the PEI Phase\r
#\r
.align 16\r
#\r
# GDT[0]: 000h: Null entry, never used.\r
#\r
.equ   NULL_SEL, . - GDT_BASE         # Selector [0]\r
GDT_BASE: \r
BootGdtTable:   \r
        .long   0\r
        .long   0\r
#\r
# Linear code segment descriptor\r
#\r
.equ     LINEAR_CODE_SEL, . - GDT_BASE         # Selector [08h]\r
        .word   0xFFFF                      # limit 0FFFFh\r
        .word   0                           # base 0\r
        .byte   0\r
        .byte   0x9B                        # present, ring 0, data, expand-up, not-writable\r
        .byte   0xCF                        # page-granular, 32-bit\r
        .byte   0\r
#\r
# System data segment descriptor\r
#\r
.equ    SYS_DATA_SEL, . - GDT_BASE         # Selector [010h]\r
        .word   0xFFFF                      # limit 0FFFFh\r
        .word   0                           # base 0\r
        .byte   0\r
        .byte   0x93                        # present, ring 0, data, expand-up, not-writable\r
        .byte   0xCF                        # page-granular, 32-bit\r
        .byte   0\r
\r
.equ            GDT_SIZE, . - BootGdtTable  # Size, in bytes\r
\r
#\r
# GDT Descriptor\r
#\r
GdtDesc:                                     # GDT descriptor\r
       .word    GDT_SIZE - 1               \r
       .long    BootGdtTable        \r
\r
ProtectedModeEntryLinearAddress:\r
ProtectedModeEntryLinearOffset:\r
       .long    ProtectedModeEntryPoint\r
       .word    LINEAR_CODE_SEL\r
Commit	Line	Data
9da59186 JY	1	#------------------------------------------------------------------------------\r
	2	#\r
	3	# Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>\r
	4	# This program and the accompanying materials\r
	5	# are licensed and made available under the terms and conditions of the BSD License\r
	6	# which accompanies this distribution. The full text of the license may be found at\r
	7	# http://opensource.org/licenses/bsd-license.php.\r
	8	#\r
	9	# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	10	# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	11	#\r
	12	# Abstract:\r
	13	#\r
	14	# This is the code that goes from real-mode to protected mode.\r
	15	# It consumes the reset vector, configures the stack.\r
	16	#\r
	17	#------------------------------------------------------------------------------\r
	18	\r
	19	\r
	20	#\r
	21	# Contrary to the name, this file contains 16 bit code as well.\r
	22	#\r
	23	.text\r
	24	#----------------------------------------------------------------------------\r
	25	#\r
	26	# Procedure: _ModuleEntryPoint\r
	27	#\r
	28	# Input: None\r
	29	#\r
	30	# Output: None\r
	31	#\r
	32	# Destroys: Assume all registers\r
	33	#\r
	34	# Description:\r
	35	#\r
	36	# Transition to non-paged flat-model protected mode from a\r
	37	# hard-coded GDT that provides exactly two descriptors.\r
	38	# This is a bare bones transition to protected mode only\r
	39	# used for a while in PEI and possibly DXE.\r
	40	#\r
	41	# After enabling protected mode, a far jump is executed to\r
	42	# transfer to PEI using the newly loaded GDT.\r
	43	#\r
	44	# Return: None\r
	45	#\r
	46	#----------------------------------------------------------------------------\r
	47	ASM_GLOBAL ASM_PFX(_ModuleEntryPoint)\r
	48	ASM_PFX(_ModuleEntryPoint):\r
	49	\r
	50	#\r
	51	# Load the GDT table in GdtDesc\r
	52	#\r
	53	.byte 0x66,0xbe #movl $GdtDesc, %esi\r
	54	.long GdtDesc\r
	55	\r
	56	.byte 0x66,0x2e,0x0f,0x01,0x14 #lgdt %cs:(%si)\r
	57	\r
	58	#\r
	59	# Transition to 16 bit protected mode\r
	60	#\r
	61	.byte 0x0f,0x20,0xc0 #movl %cr0, %eax # Get control register 0\r
	62	.byte 0x66,0x83,0xc8,0x03 #orl $0x0000003, %eax # Set PE bit (bit #0) & MP bit (bit #1)\r
	63	.byte 0x0f,0x22,0xc0 #movl %eax, %cr0 # Activate protected mode\r
	64	\r
65	#\r
66	# Now we're in 16 bit protected mode\r
67	# Set up the selectors for 32 bit protected mode entry\r
68	# \r
69	.byte 0xb8 #movw SYS_DATA_SEL, %ax\r
70	.word SYS_DATA_SEL\r
71	\r
72	.byte 0x8e,0xd8 #movw %ax, %ds\r
73	.byte 0x8e,0xc0 #movw %ax, %es\r
74	.byte 0x8e,0xe0 #movw %ax, %fs\r
75	.byte 0x8e,0xe8 #movw %ax, %gs\r
76	.byte 0x8e,0xd0 #movw %ax, %ss\r
77	\r
78	#\r
79	# Transition to Flat 32 bit protected mode\r
80	# The jump to a far pointer causes the transition to 32 bit mode\r
81	#\r
82	.byte 0x66,0xbe #movl ProtectedModeEntryLinearAddress, %esi\r
83	.long ProtectedModeEntryLinearAddress \r
84	.byte 0x66,0x2e,0xff,0x2c #jmp %cs:(%esi)\r
85	\r
86	#\r
87	# Protected mode portion initializes stack, configures cache, and calls C entry point\r
88	#\r
89	\r
90	#----------------------------------------------------------------------------\r
91	#\r
92	# Procedure: ProtectedModeEntryPoint\r
93	#\r
94	# Input: Executing in 32 Bit Protected (flat) mode\r
95	# cs: 0-4GB\r
96	# ds: 0-4GB\r
97	# es: 0-4GB\r
98	# fs: 0-4GB\r
99	# gs: 0-4GB\r
100	# ss: 0-4GB\r
101	#\r
102	# Output: This function never returns\r
103	#\r
104	# Destroys:\r
105	# ecx\r
106	# edi\r
107	# esi\r
108	# esp\r
109	#\r
110	# Description:\r
111	# Perform any essential early platform initilaisation\r
112	# Setup a stack\r
113	#\r
114	#----------------------------------------------------------------------------\r
115	ProtectedModeEntryPoint:\r
116	#\r
117	# Dummy function. Consume 2 API to make sure they can be linked.\r
118	#\r
119	movl ASM_PFX(TempRamInitApi), %eax\r
120	movl ASM_PFX(FspInitApi), %eax\r
121	#\r
122	# Should never return\r
123	#\r
124	jmp . #'$'\r
125	\r
126	#\r
127	# ROM-based Global-Descriptor Table for the PEI Phase\r
128	#\r
129	.align 16\r
130	#\r
131	# GDT[0]: 000h: Null entry, never used.\r
132	#\r
133	.equ NULL_SEL, . - GDT_BASE # Selector [0]\r
134	GDT_BASE: \r
135	BootGdtTable: \r
136	.long 0\r
137	.long 0\r
138	#\r
139	# Linear code segment descriptor\r
140	#\r
141	.equ LINEAR_CODE_SEL, . - GDT_BASE # Selector [08h]\r
142	.word 0xFFFF # limit 0FFFFh\r
143	.word 0 # base 0\r
144	.byte 0\r
145	.byte 0x9B # present, ring 0, data, expand-up, not-writable\r
146	.byte 0xCF # page-granular, 32-bit\r
147	.byte 0\r
148	#\r
149	# System data segment descriptor\r
150	#\r
151	.equ SYS_DATA_SEL, . - GDT_BASE # Selector [010h]\r
152	.word 0xFFFF # limit 0FFFFh\r
153	.word 0 # base 0\r
154	.byte 0\r
155	.byte 0x93 # present, ring 0, data, expand-up, not-writable\r
156	.byte 0xCF # page-granular, 32-bit\r
157	.byte 0\r
158	\r
159	.equ GDT_SIZE, . - BootGdtTable # Size, in bytes\r
160	\r
161	#\r
162	# GDT Descriptor\r
163	#\r
164	GdtDesc: # GDT descriptor\r
165	.word GDT_SIZE - 1 \r
166	.long BootGdtTable \r
167	\r
168	ProtectedModeEntryLinearAddress:\r
169	ProtectedModeEntryLinearOffset:\r
170	.long ProtectedModeEntryPoint\r
171	.word LINEAR_CODE_SEL\r