kernel.git/arch/x86/boot, branch linux-2.6.30.y

x86, setup (2.6.30-stable) fix 80x34 and 80x60 console modes

2009-07-30T21:40:09Z

Note: this is not in upstream since upstream is not affected due to the new "BIOS glovebox" subsystem. As coded, most INT10 calls in video-vga.c allow the compiler to assume EAX remains unchanged across them, which is not always the case. This triggers an optimisation issue that causes vga_set_vertical_end() to be called with an incorrect number of scanlines. Fix this by beefing up the asm constraints on these calls. Reported-by: Marc Aurele La France Signed-off-by: Marc Aurele La France Acked-by: H. Peter Anvin Signed-off-by: Greg Kroah-Hartman

x86, relocs: ignore R_386_NONE in kernel relocation entries

2009-05-26T05:52:49Z

For relocatable 32bit kernels, boot/compressed/relocs.c processes relocation entries in the kernel image and appends it to the kernel image such that boot/compressed/head_32.S can relocate the kernel. The kernel image is one statically linked object and only uses two relocation types - R_386_PC32 and R_386_32, of the two only the latter needs massaging during kernel relocation and thus handled by relocs. R_386_PC32 is ignored and all other relocation types are considered error. When the target of a relocation resides in a discarded section, binutils doesn't throw away the relocation record but nullifies it by changing it to R_386_NONE, which unfortunately makes relocs fail. The problem was triggered by yet out-of-tree x86 stack unwind patches but given the binutils behavior, ignoring R_386_NONE is the right thing to do. The problem has been tracked down to binutils behavior by Jan Beulich. [ Impact: fix build with certain binutils by ignoring R_386_NONE ] Signed-off-by: Tejun Heo Cc: Jan Beulich Cc: Ingo Molnar LKML-Reference: <4A1B8150.40702@kernel.org> Signed-off-by: H. Peter Anvin

x86, setup: revert ACPI 3 E820 extended attributes support

2009-05-22T18:14:02Z

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 Signed-off-by: H. Peter Anvin Acked-by: Len Brown Cc: Chuck Ebbert Cc: Kyle McMartin Cc: Matt Domsch

x86, setup: un-resequence mode setting for VGA 80x34 and 80x60 modes

2009-04-07T17:59:25Z

Impact: Fixes these modes on at least one system The rewrite of the setup code into C resequenced the font setting and register reprogramming phases of configuring nonstandard VGA modes which use 480 scan lines in text mode. However, there exists at least one board (Micro-Star MS-7383 version 2.0) on which this resequencing causes an unusable display. Revert to the original sequencing: set up 480-line mode, install the font, and then adjust the vertical end register appropriately. This failure was masked by the fact that the 480-line setup was broken until checkin 5f641356127712fbdce0eee120e5ce115860c17f (therefore this is not a -stable candidate bug fix.) Reported-by: Andi Kleen Signed-off-by: H. Peter Anvin

Merge branch 'dma-debug' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into x86/urgent

2009-04-03T14:35:09Z

x86, setup: compile with -DDISABLE_BRANCH_PROFILING

2009-04-03T14:34:45Z

Impact: code size reduction (possibly critical) The x86 boot and decompression code has no use of the branch profiling constructs, so disable them. This would bloat the setup code by as much as 14K, eating up a fairly large chunk of the 32K area we are guaranteed to have. Signed-off-by: H. Peter Anvin Signed-off-by: Ingo Molnar

x86, setup: guard against pre-ACPI 3 e820 code not updating %ecx

2009-04-01T18:35:00Z

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

x86, setup: ACPI 3, BIOS workaround for E820-probing code

2009-03-29T01:20:07Z

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

x86, setup: preemptively save/restore edi and ebp around INT 15 E820

2009-03-29T01:18:20Z

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

x86, setup: mark %esi as clobbered in E820 BIOS call

2009-03-28T19:45:39Z

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 Signed-off-by: Michael K Johnson Signed-off-by: H. Peter Anvin Cc: stable@kernel.org