Files
system76-edk2/UefiCpuPkg/ResetVector/Vtf0/X64/PageTables1G.asm
Ashraf Ali S 60d8bb9f28 UefiCpuPkg: VTF0 Linear-Address Translation to a 1-GByte Page till 512GB
REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3473

X64 Reset Vector Code can access the memory range till 4GB using the
Linear-Address Translation to a 2-MByte Page, when user wants to use
more than 4G using 2M Page it will leads to use more number of Page
table entries. using the 1-GByte Page table user can use more than
4G Memory by reducing the page table entries using 1-GByte Page,
this patch attached can access memory range till 512GByte via Linear-
Address Translation to a 1-GByte Page.

Build Tool: if the nasm is not found it will throw Build errors like
FileNotFoundError: [WinError 2]The system cannot find the file specified
run the command wil try except block to get meaningful error message

Test Result: Tested in both Simulation environment and Hardware
both works fine without any issues.

Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Debkumar De <debkumar.de@intel.com>
Cc: Harry Han <harry.han@intel.com>
Cc: Catharine West <catharine.west@intel.com>
Cc: Sangeetha V <sangeetha.v@intel.com>
Cc: Rangasai V Chaganty <rangasai.v.chaganty@intel.com>
Cc: Sahil Dureja <sahil.dureja@intel.com>
Signed-off-by: Ashraf Ali S <ashraf.ali.s@intel.com>
2021-09-16 14:18:27 +00:00

54 lines
1.5 KiB
NASM

;------------------------------------------------------------------------------
; @file
; Emits Page Tables for 1:1 mapping of the addresses 0 - 0x8000000000 (512GB)
;
; Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
; SPDX-License-Identifier: BSD-2-Clause-Patent
; Linear-Address Translation to a 1-GByte Page
;
;------------------------------------------------------------------------------
BITS 64
%define ALIGN_TOP_TO_4K_FOR_PAGING
%define PAGE_PDP_ATTR (PAGE_ACCESSED + \
PAGE_READ_WRITE + \
PAGE_PRESENT)
%define PAGE_PDP_1G_ATTR (PAGE_ACCESSED + \
PAGE_READ_WRITE + \
PAGE_DIRTY + \
PAGE_PRESENT + \
PAGE_SIZE)
%define PGTBLS_OFFSET(x) ((x) - TopLevelPageDirectory)
%define PGTBLS_ADDR(x) (ADDR_OF(TopLevelPageDirectory) + (x))
%define PDP(offset) (ADDR_OF(TopLevelPageDirectory) + (offset) + \
PAGE_PDP_ATTR)
%define PDP_1G(x) ((x << 30) + PAGE_PDP_1G_ATTR)
ALIGN 16
TopLevelPageDirectory:
;
; Top level Page Directory Pointers (1 * 512GB entry)
;
DQ PDP(0x1000)
TIMES 0x1000-PGTBLS_OFFSET($) DB 0
;
; Next level Page Directory Pointers (512 * 1GB entries => 512GB)
;
%assign i 0
%rep 512
DQ PDP_1G(i)
%assign i i+1
%endrep
TIMES 0x2000-PGTBLS_OFFSET($) DB 0
EndOfPageTables: