Impact: BIOS proofing
"Glove box" off BIOS interrupts in the EDD code.
LKML-Reference: <49DE7F79.4030106@zytor.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Some BIOSes do not indicate error when trying to read from non-
existing device. Zero buffer before reading and check that we
possibly have valid MBR by looking for MBR magic.
This was fixed in different way for edd.S in
http://marc.info/?l=linux-kernel&m=114087765422490&w=2, but lost
again when edd.S was rewritten in C.
Signed-off-by: Andrey Borzenkov < arvidjaar@mail.ru>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
> This is regression but old enough. Apparently I had for whatever reasons
> EDD turned off till recently. This is 2.6.27-rc5 just in case.
>
> In 2006 I fixed ghost devices due to buggy BIOS:
>
> http://marc.info/?l=linux-kernel&m=114087765422490&w=2
>
> Later edd.S has been rewritten in C, and apparently this patch has been
> lost:
>
> {pts/1}% ls /sys/firmware/edd
> int13_dev80/ int13_dev84/ int13_dev88/ int13_dev8c/
> int13_dev81/ int13_dev85/ int13_dev89/ int13_dev8d/
> int13_dev82/ int13_dev86/ int13_dev8a/ int13_dev8e/
> int13_dev83/ int13_dev87/ int13_dev8b/ int13_dev8f/
>
> But I have just a single disk. This is the same system BTW.
Some BIOSes do not always set CF on error before return from int13.
The patch adds additional check for status being zero (AH == 0).
This was fixed for edd.S in
http://marc.info/?l=linux-kernel&m=114087765422490&w=2, but lost
again when edd.S was rewritten in C.
Signed-off-by: Andrey Borzenkov <arvidjaar@mail.ru>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Without checking the return value of get_edd_info() and adding the
entry only in the success case, 6 devices show up under
/sys/firmware/edd/, no matter how many devices are actually present.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Add a kernel parameter option to 'edd' to enable/disable BIOS Enhanced Disk
Drive Services. CONFIG_EDD_OFF disables EDD while still compiling EDD into
the kernel. Default behavior can be forced using 'edd=on' or 'edd=off' as
a kernel parameter.
[akpm@linux-foundation.org: fix kernel-parameters.txt]
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Matt Domsch <Matt_Domsch@dell.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Tell the user to specify edd=off in the case of EDD probing hangs.
Per LKML discussion.
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>
Unnecessary capitals are shouting; no need for it here.
Thus, change "OK" to "ok" and add a space.
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>
On early boot, probing the Bios for EDD happens without any message.
Enhanced Disk Drive Services (EDD) is a mechanism to match x86 BIOS device
names (int13 device 80h) to Linux device names (e.g. /dev/sda, /dev/hda)
There are buggy Bios out there having problems with EDD. This can be problems
with the Bios itself or with addon cards, too.
This patch is adds an informational message on early boot.
CONFIG_EDD is not set with defconfig, but with allmodconfig (i.e. CONFIG_EDD=m)
so the EDD probe may be active on early boot on many systems nowadays.
I can tell, that the probe is active on SuSE distro and with that I have seen
more than one system hanging endlessly with those "black screen with a blinking
cursor in the the upper left" on installation, making it difficult for the end-
user to find out, what`s the issue.
For sure I have seen this on FujitsuSiemens PCs with i810 and with i815 chipset.
This one also honours the "quiet" bootparam.
Also see:
http://marc.info/?l=linux-kernel&m=119781937207969&w=2http://marc.info/?l=linux-kernel&m=119783934032326&w=2http://marc.info/?l=linux-kernel&m=119783678529100&w=2
Signed-off-by: Roland Kletzing <devzero@web.de>
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>
H. Peter Anvin