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path: root/arch/x86/boot/memory.c
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2011-04-25x86, setup: When probing memory with e801, use ax/bx as a pairH. Peter Anvin
When we use BIOS function e801 to probe memory, we should use ax/bx (or cx/dx) as a pair, not mix and match. This was a typo during the translation from assembly code, and breaks at least one set of machines in the field (which return cx = dx = 0). Reported-and-tested-by: Chris Samuel <chris@csamuel.org> Fix-proposed-by: Thomas Meyer <thomas@m3y3r.de> Link: http://lkml.kernel.org/r/1303566747.12067.10.camel@localhost.localdomain
2009-05-23Merge branch 'x86/urgent' into x86/setupH. Peter Anvin
Resolved conflicts: arch/x86/boot/memory.c Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-22x86, setup: revert ACPI 3 E820 extended attributes supportH. Peter Anvin
Remove ACPI 3 E820 extended memory attributes support. At least one vendor actively set all the flags to zero, but left ECX on return at 24. This bug may be present in other BIOSes. The breakage functionally means the ACPI 3 flags are probably completely useless, and that no OS any time soon is going to rely on their existence. Therefore, drop support completely. We may want to revisit this question in the future, if we find ourselves actually needing the flags. This reverts all or part of the following checkins: cd670599b7b00d9263f6f11a05c0edeb9cbedaf3 c549e71d073a6e9a4847497344db28a784061455 However, retain the part from the latter commit that copies e820 into a temporary buffer; that is an unrelated BIOS workaround. Put in a comment to explain that part. See https://bugzilla.redhat.com/show_bug.cgi?id=499396 for some additional information. [ Impact: detect all memory on affected machines ] Reported-by: Thomas J. Baker <tjb@unh.edu> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Acked-by: Len Brown <len.brown@intel.com> Cc: Chuck Ebbert <cebbert@redhat.com> Cc: Kyle McMartin <kmcmartin@redhat.com> Cc: Matt Domsch <matt_domsch@dell.com>
2009-04-09x86, setup: "glove box" BIOS interrupts in the core boot codeH. Peter Anvin
Impact: BIOS proofing "Glove box" off BIOS interrupts in the core boot code. LKML-Reference: <49DE7F79.4030106@zytor.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-04-01x86, setup: guard against pre-ACPI 3 e820 code not updating %ecxH. Peter Anvin
Impact: BIOS bug safety For pre-ACPI 3 BIOSes, pre-initialize the end of the e820 buffer just in case the BIOS returns an unchanged %ecx but without actually touching the ACPI 3 extended flags field. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-28x86, setup: ACPI 3, BIOS workaround for E820-probing codeH. Peter Anvin
Impact: ACPI 3 spec compliance, BIOS bug workaround The ACPI 3 spec added another field to the E820 buffer -- which is backwards incompatible, since it contains a validity bit. Furthermore, there has been at least one report of a BIOS which assumes that the buffer it is pointed at is the same buffer as for the previous E820 call. Therefore, read the data into a temporary buffer and copy the standard part of it if and only if the valid bit is set. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-28x86, setup: preemptively save/restore edi and ebp around INT 15 E820H. Peter Anvin
Impact: BIOS bugproofing Since there are BIOSes known to clobber %ebx and %esi for INT 15 E820, assume there is something out there clobbering %edi and/or %ebp too, and don't wait for it to fail. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-28x86, setup: mark %esi as clobbered in E820 BIOS callMichael K. Johnson
Jordan Hargrave diagnosed a BIOS clobbering %esi in the E820 call. That particular BIOS has been fixed, but there is a possibility that this is responsible for other occasional reports of early boot failure, and it does not hurt to add %esi to the clobbers. -stable candidate patch. Cc: Justin Forbes <jmforbes@linuxtx.org> Signed-off-by: Michael K Johnson <johnsonm@rpath.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: stable@kernel.org
2008-08-18x86: fix build warnings in real mode codeAndi Kleen
This recent patch commit c3965bd15118742d72b4bc1a290d37b3f081eb98 Author: Paul Jackson <pj@sgi.com> Date: Wed May 14 08:15:34 2008 -0700 x86 boot: proper use of ARRAY_SIZE instead of repeated E820MAX constant caused these new warnings during a normal build: In file included from linux-2.6/arch/x86/boot/memory.c:17: linux-2.6/include/linux/log2.h: In function '__ilog2_u32': linux-2.6/include/linux/log2.h:34: warning: implicit declaration of function 'fls' linux-2.6/include/linux/log2.h: In function '__ilog2_u64': linux-2.6/include/linux/log2.h:42: warning: implicit declaration of function 'fls64' linux-2.6/include/linux/log2.h: In function '__roundup_pow_of_two ': linux-2.6/include/linux/log2.h:63: warning: implicit declaration of function 'fls_long' I tried to fix them in log2.h, but it's difficult because the real mode environment is completely different from a normal kernel environment. Instead define an own ARRAY_SIZE macro in boot.h, similar to the other private macros there. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-25x86 boot: proper use of ARRAY_SIZE instead of repeated E820MAX constantPaul Jackson
This patch is motivated by a subsequent patch which will allow for more memory map entries on EFI supported systems than can be passed via the x86 legacy BIOS E820 interface. The legacy interface is limited to E820MAX == 128 memory entries, and that "E820MAX" manifest constant was used as the size for several arrays and loops over those arrays. The primary change in this patch is to change code loop sizes over those arrays from using the constant E820MAX, to using the ARRAY_SIZE() macro evaluated for the array being looped. That way, a subsequent patch can change the size of some of these arrays, without breaking this code. This patch also adds a parameter to the sanitize_e820_map() routine, which had an implicit size for the array passed it of E820MAX entries. This new parameter explicitly passes the size of said array. Once again, this will allow a subsequent patch to change that array size for some calls to sanitize_e820_map() without breaking the code. As part of enhancing the sanitize_e820_map() interface this way, I further combined the unnecessarily distinct x86_32 and x86_64 declarations for this routine into a single, commonly used, declaration. This patch in itself should make no difference to the resulting kernel binary. [ mingo@elte.hu: merged to -tip ] Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19x86: remove pointless commentsWANG Cong
Remove old comments that include the old arch/i386 directory. Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-26x86: handle BIOSes which terminate e820 with CF=1 and no SMAPH. Peter Anvin
The proper way to terminate the e820 chain is with %ebx == 0 on the last legitimate memory block. However, several BIOSes don't do that and instead return error (CF = 1) when trying to read off the end of the list. For this error return, %eax doesn't necessarily return the SMAP signature -- correctly so, since %ah should contain an error code in this case. To deal with some particularly broken BIOSes, we clear the entire e820 chain if the SMAP signature is missing in the middle, indicating a plain insane e820 implementation. However, we need to make the test for CF = 1 before the SMAP check. This fixes at least one HP laptop (nc6400) for which none of the memory-probing methods (e820, e801, 88) functioned fully according to spec. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-11i386: move bootThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>