libpayload-x86: Enable SSE and FPU when present

Allows to use SSE and floating point in payloads without digging to
much into x86 assembly code.

Tested on Lenovo T500 (Intel Core2Duo).
Both floating point operation and SSE is properly working.

Change-Id: I4a5fc633f158de421b70435a8bfdc0dcaa504c72
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/18345
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
This commit is contained in:
Patrick Rudolph 2017-01-15 10:49:48 +01:00 committed by Martin Roth
parent f13bd41c50
commit b854ae2649
1 changed files with 43 additions and 0 deletions

View File

@ -2,6 +2,7 @@
* This file is part of the libpayload project.
*
* Copyright (C) 2008 Advanced Micro Devices, Inc.
* Copyright (C) 2017 Patrick Rudolph <siro@das-labor.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@ -89,6 +90,48 @@ _init:
movl $_stack, %esp
pushl %eax
/* Enable special x86 functions if present. */
pushl %eax
pushl %ebx
pushl %ecx
pushl %edx
movl $0, %eax
cpuid
/* Test if CPUID(eax=1) is available. */
test %eax, %eax
je cpuid_done
/* Get CPU features. */
movl $1, %eax
cpuid
cpuid_fpu:
/* Test if x87 FPU is present */
test $1, %edx
je cpuid_sse
fninit
movl %cr0, %eax
andl $0xFFFFFFFB, %eax /* clear EM */
orl $0x00000022, %eax /* set MP, NE */
movl %eax, %cr0
cpuid_sse:
/* Test if SSE is available */
test $0x02000000, %edx
je cpuid_done
movl %cr4, %eax
orl $0x00000600, %eax /* set OSFXSR, OSXMMEXCPT */
movl %eax, %cr4
cpuid_done:
popl %edx
popl %ecx
popl %ebx
popl %eax
/* Let's rock. */
call start_main