diff options
Diffstat (limited to 'roms/edk2/OvmfPkg/XenResetVector/Ia16')
| -rw-r--r-- | roms/edk2/OvmfPkg/XenResetVector/Ia16/Real16ToFlat32.asm | 137 | ||||
| -rw-r--r-- | roms/edk2/OvmfPkg/XenResetVector/Ia16/ResetVectorVtf0.asm | 79 |
2 files changed, 216 insertions, 0 deletions
diff --git a/roms/edk2/OvmfPkg/XenResetVector/Ia16/Real16ToFlat32.asm b/roms/edk2/OvmfPkg/XenResetVector/Ia16/Real16ToFlat32.asm new file mode 100644 index 000000000..36ea74f7f --- /dev/null +++ b/roms/edk2/OvmfPkg/XenResetVector/Ia16/Real16ToFlat32.asm @@ -0,0 +1,137 @@ +;------------------------------------------------------------------------------
+; @file
+; Transition from 16 bit real mode into 32 bit flat protected mode
+;
+; Copyright (c) 2008 - 2010, Intel Corporation. All rights reserved.<BR>
+; Copyright (c) 2019, Citrix Systems, Inc.
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+;------------------------------------------------------------------------------
+
+%define SEC_DEFAULT_CR0 0x00000023
+%define SEC_DEFAULT_CR4 0x640
+
+BITS 16
+
+;
+; Modified: EAX, EBX
+;
+; @param[out] DS Selector allowing flat access to all addresses
+; @param[out] ES Selector allowing flat access to all addresses
+; @param[out] FS Selector allowing flat access to all addresses
+; @param[out] GS Selector allowing flat access to all addresses
+; @param[out] SS Selector allowing flat access to all addresses
+;
+TransitionFromReal16To32BitFlat:
+
+ debugShowPostCode POSTCODE_16BIT_MODE
+
+ cli
+
+ mov bx, 0xf000
+ mov ds, bx
+
+ mov bx, ADDR16_OF(gdtr)
+
+o32 lgdt [cs:bx]
+
+ mov eax, SEC_DEFAULT_CR0
+ mov cr0, eax
+
+ jmp LINEAR_CODE_SEL:dword ADDR_OF(jumpTo32BitAndLandHere)
+BITS 32
+jumpTo32BitAndLandHere:
+
+ mov eax, SEC_DEFAULT_CR4
+ mov cr4, eax
+
+ debugShowPostCode POSTCODE_32BIT_MODE
+
+ mov ax, LINEAR_SEL
+ mov ds, ax
+ mov es, ax
+ mov fs, ax
+ mov gs, ax
+ mov ss, ax
+
+ ; parameter for Flat32SearchForBfvBase
+ xor eax, eax ; Start searching from top of 4GB for BfvBase
+
+ OneTimeCallRet TransitionFromReal16To32BitFlat
+
+ALIGN 2
+
+gdtr:
+ dw GDT_END - GDT_BASE - 1 ; GDT limit
+ dd ADDR_OF(GDT_BASE)
+
+ALIGN 16
+
+;
+; Macros for GDT entries
+;
+
+%define PRESENT_FLAG(p) (p << 7)
+%define DPL(dpl) (dpl << 5)
+%define SYSTEM_FLAG(s) (s << 4)
+%define DESC_TYPE(t) (t)
+
+; Type: data, expand-up, writable, accessed
+%define DATA32_TYPE 3
+
+; Type: execute, readable, expand-up, accessed
+%define CODE32_TYPE 0xb
+
+; Type: execute, readable, expand-up, accessed
+%define CODE64_TYPE 0xb
+
+%define GRANULARITY_FLAG(g) (g << 7)
+%define DEFAULT_SIZE32(d) (d << 6)
+%define CODE64_FLAG(l) (l << 5)
+%define UPPER_LIMIT(l) (l)
+
+;
+; The Global Descriptor Table (GDT)
+;
+
+GDT_BASE:
+; null descriptor
+NULL_SEL equ $-GDT_BASE
+ DW 0 ; limit 15:0
+ DW 0 ; base 15:0
+ DB 0 ; base 23:16
+ DB 0 ; sys flag, dpl, type
+ DB 0 ; limit 19:16, flags
+ DB 0 ; base 31:24
+
+; linear data segment descriptor
+LINEAR_SEL equ $-GDT_BASE
+ DW 0xffff ; limit 15:0
+ DW 0 ; base 15:0
+ DB 0 ; base 23:16
+ DB PRESENT_FLAG(1)|DPL(0)|SYSTEM_FLAG(1)|DESC_TYPE(DATA32_TYPE)
+ DB GRANULARITY_FLAG(1)|DEFAULT_SIZE32(1)|CODE64_FLAG(0)|UPPER_LIMIT(0xf)
+ DB 0 ; base 31:24
+
+; linear code segment descriptor
+LINEAR_CODE_SEL equ $-GDT_BASE
+ DW 0xffff ; limit 15:0
+ DW 0 ; base 15:0
+ DB 0 ; base 23:16
+ DB PRESENT_FLAG(1)|DPL(0)|SYSTEM_FLAG(1)|DESC_TYPE(CODE32_TYPE)
+ DB GRANULARITY_FLAG(1)|DEFAULT_SIZE32(1)|CODE64_FLAG(0)|UPPER_LIMIT(0xf)
+ DB 0 ; base 31:24
+
+%ifdef ARCH_X64
+; linear code (64-bit) segment descriptor
+LINEAR_CODE64_SEL equ $-GDT_BASE
+ DW 0xffff ; limit 15:0
+ DW 0 ; base 15:0
+ DB 0 ; base 23:16
+ DB PRESENT_FLAG(1)|DPL(0)|SYSTEM_FLAG(1)|DESC_TYPE(CODE64_TYPE)
+ DB GRANULARITY_FLAG(1)|DEFAULT_SIZE32(0)|CODE64_FLAG(1)|UPPER_LIMIT(0xf)
+ DB 0 ; base 31:24
+%endif
+
+GDT_END:
+
diff --git a/roms/edk2/OvmfPkg/XenResetVector/Ia16/ResetVectorVtf0.asm b/roms/edk2/OvmfPkg/XenResetVector/Ia16/ResetVectorVtf0.asm new file mode 100644 index 000000000..56749bdbc --- /dev/null +++ b/roms/edk2/OvmfPkg/XenResetVector/Ia16/ResetVectorVtf0.asm @@ -0,0 +1,79 @@ +;------------------------------------------------------------------------------
+; @file
+; First code executed by processor after resetting.
+;
+; Copyright (c) 2008 - 2014, Intel Corporation. All rights reserved.<BR>
+; Copyright (c) 2019, Citrix Systems, Inc.
+;
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+;------------------------------------------------------------------------------
+
+BITS 16
+
+ALIGN 16
+
+;
+; Pad the image size to 4k when page tables are in VTF0
+;
+; If the VTF0 image has page tables built in, then we need to make
+; sure the end of VTF0 is 4k above where the page tables end.
+;
+; This is required so the page tables will be 4k aligned when VTF0 is
+; located just below 0x100000000 (4GB) in the firmware device.
+;
+%ifdef ALIGN_TOP_TO_4K_FOR_PAGING
+ TIMES (0x1000 - ($ - EndOfPageTables) - (fourGigabytes - xenPVHEntryPoint)) DB 0
+%endif
+
+BITS 32
+xenPVHEntryPoint:
+;
+; Entry point to use when running as a Xen PVH guest. (0xffffffd0)
+;
+; Description of the expected state of the machine when this entry point is
+; used can be found at:
+; https://xenbits.xenproject.org/docs/unstable/misc/pvh.html
+;
+ jmp xenPVHMain
+
+BITS 16
+ALIGN 16
+
+applicationProcessorEntryPoint:
+;
+; Application Processors entry point
+;
+; GenFv generates code aligned on a 4k boundary which will jump to this
+; location. (0xffffffe0) This allows the Local APIC Startup IPI to be
+; used to wake up the application processors.
+;
+ jmp EarlyApInitReal16
+
+ALIGN 8
+
+ DD 0
+
+;
+; The VTF signature
+;
+; VTF-0 means that the VTF (Volume Top File) code does not require
+; any fixups.
+;
+vtfSignature:
+ DB 'V', 'T', 'F', 0
+
+ALIGN 16
+
+resetVector:
+;
+; Reset Vector
+;
+; This is where the processor will begin execution
+;
+ jmp EarlyBspInitReal16
+
+ALIGN 16
+
+fourGigabytes:
+
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