mirror of
https://github.com/CloverHackyColor/CloverBootloader.git
synced 2024-12-01 12:53:27 +01:00
52 lines
1.3 KiB
NASM
52 lines
1.3 KiB
NASM
|
;------------------------------------------------------------------------------
|
||
|
|
;*
|
||
|
|
;* Copyright (c) 2009 - 2017, Intel Corporation. All rights reserved.<BR>
|
||
|
|
;* SPDX-License-Identifier: BSD-2-Clause-Patent
|
||
|
|
;*
|
||
|
|
;*
|
||
|
|
;------------------------------------------------------------------------------
|
||
|
|
|
||
|
|
SECTION .rodata
|
||
|
|
;
|
||
|
|
; Float control word initial value:
|
||
|
|
; all exceptions masked, double-extended-precision, round-to-nearest
|
||
|
|
;
|
||
|
|
mFpuControlWord: DW 0x37F
|
||
|
|
;
|
||
|
|
; Multimedia-extensions control word:
|
||
|
|
; all exceptions masked, round-to-nearest, flush to zero for masked underflow
|
||
|
|
;
|
||
|
|
mMmxControlWord: DD 0x1F80
|
||
|
|
|
||
|
|
DEFAULT REL
|
||
|
|
SECTION .text
|
||
|
|
|
||
|
|
;
|
||
|
|
; Initializes floating point units for requirement of UEFI specification.
|
||
|
|
;
|
||
|
|
; This function initializes floating-point control word to 0x027F (all exceptions
|
||
|
|
; masked,double-precision, round-to-nearest) and multimedia-extensions control word
|
||
|
|
; (if supported) to 0x1F80 (all exceptions masked, round-to-nearest, flush to zero
|
||
|
|
; for masked underflow).
|
||
|
|
;
|
||
|
|
global ASM_PFX(InitializeFloatingPointUnits)
|
||
|
|
ASM_PFX(InitializeFloatingPointUnits):
|
||
|
|
|
||
|
|
;
|
||
|
|
; Initialize floating point units
|
||
|
|
;
|
||
|
|
finit
|
||
|
|
fldcw [mFpuControlWord]
|
||
|
|
|
||
|
|
;
|
||
|
|
; Set OSFXSR bit 9 in CR4
|
||
|
|
;
|
||
|
|
mov rax, cr4
|
||
|
|
or rax, BIT9
|
||
|
|
mov cr4, rax
|
||
|
|
|
||
|
|
ldmxcsr [mMmxControlWord]
|
||
|
|
|
||
|
|
ret
|
||
|
|
|