From: Matt Fleming <matt@console-pimps.org>
To: linux-efi@vger.kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>, Borislav Petkov <bp@alien8.de>,
Alan Cox <alan@lxorguk.ukuu.org.uk>,
Matthew Garrett <mjg59@srcf.ucam.org>,
linux-kernel@vger.kernel.org,
Matt Fleming <matt.fleming@intel.com>
Subject: [PATCH 12/13] x86/boot: Don't overwrite cr4 when enabling PAE
Date: Tue, 4 Mar 2014 13:14:20 +0000 [thread overview]
Message-ID: <1393938861-16797-13-git-send-email-matt@console-pimps.org> (raw)
In-Reply-To: <1393938861-16797-1-git-send-email-matt@console-pimps.org>
From: Matt Fleming <matt.fleming@intel.com>
Some EFI firmware makes use of the FPU during boottime services and
clearing X86_CR4_OSFXSR by overwriting %cr4 causes the firmware to
crash.
Add the PAE bit explicitly instead of trashing the existing contents,
leaving the rest of the bits as the firmware set them.
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
---
arch/x86/boot/compressed/head_64.S | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 37c741b0d2ac..4f40cddd025d 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -113,7 +113,8 @@ ENTRY(startup_32)
lgdt gdt(%ebp)
/* Enable PAE mode */
- movl $(X86_CR4_PAE), %eax
+ movl %cr4, %eax
+ orl $X86_CR4_PAE, %eax
movl %eax, %cr4
/*
--
1.8.5.3
next prev parent reply other threads:[~2014-03-04 13:16 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-04 13:14 [PATCH v2 00/13] EFI mixed mode Matt Fleming
2014-03-04 13:14 ` [PATCH 01/13] x86/boot: Cleanup header.S by removing some #ifdefs Matt Fleming
2014-03-04 13:14 ` [PATCH 02/13] x86, tools: Consolidate #ifdef code Matt Fleming
2014-03-04 13:14 ` [PATCH 03/13] x86/mm/pageattr: Always dump the right page table in an oops Matt Fleming
2014-03-04 13:14 ` [PATCH 04/13] x86/efi: Delete dead code when checking for non-native Matt Fleming
2014-03-04 13:14 ` [PATCH 05/13] efi: Add separate 32-bit/64-bit definitions Matt Fleming
2014-03-04 13:14 ` [PATCH v2 06/13] x86/efi: Build our own EFI services pointer table Matt Fleming
2014-03-22 0:52 ` Roy Franz
2014-03-22 11:05 ` Matt Fleming
2014-03-22 20:16 ` Roy Franz
2014-03-25 22:47 ` Roy Franz
2014-03-26 9:10 ` Matt Fleming
2014-03-26 18:34 ` [tip:x86/efi] x86, efi: Abstract x86 efi_early calls tip-bot for Matt Fleming
2014-03-25 22:40 ` [PATCH] Add efi_early_call() macro Roy Franz
2014-03-26 8:59 ` Matt Fleming
2014-03-26 17:40 ` Roy Franz
2014-03-04 13:14 ` [PATCH 07/13] x86/efi: Add early thunk code to go from 64-bit to 32-bit Matt Fleming
2014-03-04 13:14 ` [PATCH 08/13] x86/efi: Split the boot stub into 32/64 code paths Matt Fleming
2014-03-04 13:14 ` [PATCH 09/13] x86/efi: Firmware agnostic handover entry points Matt Fleming
2014-03-04 13:14 ` [PATCH 10/13] x86/efi: Add mixed runtime services support Matt Fleming
2014-03-04 13:14 ` [PATCH 11/13] x86/efi: Wire up CONFIG_EFI_MIXED Matt Fleming
2014-03-04 13:14 ` Matt Fleming [this message]
2014-03-04 13:14 ` [PATCH 13/13] x86/efi: Re-disable interrupts after calling firmware services Matt Fleming
2014-03-06 21:27 ` [PATCH v2 00/13] EFI mixed mode David Rientjes
2014-03-06 21:40 ` Matt Fleming
2014-03-07 10:11 ` David Rientjes
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