From 8c4dd6068221cd1d0d90490ace80eb4344914a8c Mon Sep 17 00:00:00 2001
From: Tim Gardner <tim.gardner@canonical.com>
Date: Tue, 29 Apr 2008 01:02:45 -0700
Subject: [PATCH] edd: add default mode CONFIG_EDD_OFF=n, override with
edd={on,off}
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>
---
Documentation/kernel-parameters.txt | 3 +--
arch/x86/boot/edd.c | 10 +++++++++-
drivers/firmware/Kconfig | 9 +++++++++
3 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 5afc21b20a92c..3ce193f865651 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -627,8 +627,7 @@ and is between 256 and 4096 characters. It is defined in the file
eata= [HW,SCSI]
edd= [EDD]
- Format: {"of[f]" | "sk[ipmbr]"}
- See comment in arch/i386/boot/edd.S
+ Format: {"off" | "on" | "skip[mbr]"}
eisa_irq_edge= [PARISC,HW]
See header of drivers/parisc/eisa.c.
diff --git a/arch/x86/boot/edd.c b/arch/x86/boot/edd.c
index d84a48ece7850..03399d64013b2 100644
--- a/arch/x86/boot/edd.c
+++ b/arch/x86/boot/edd.c
@@ -126,17 +126,25 @@ void query_edd(void)
{
char eddarg[8];
int do_mbr = 1;
+#ifdef CONFIG_EDD_OFF
+ int do_edd = 0;
+#else
int do_edd = 1;
+#endif
int be_quiet;
int devno;
struct edd_info ei, *edp;
u32 *mbrptr;
if (cmdline_find_option("edd", eddarg, sizeof eddarg) > 0) {
- if (!strcmp(eddarg, "skipmbr") || !strcmp(eddarg, "skip"))
+ if (!strcmp(eddarg, "skipmbr") || !strcmp(eddarg, "skip")) {
+ do_edd = 1;
do_mbr = 0;
+ }
else if (!strcmp(eddarg, "off"))
do_edd = 0;
+ else if (!strcmp(eddarg, "on"))
+ do_edd = 1;
}
be_quiet = cmdline_find_option_bool("quiet");
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 40ffd767647d6..dc2cec6127d18 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -17,6 +17,15 @@ config EDD
obscure configurations. Most disk controller BIOS vendors do
not yet implement this feature.
+config EDD_OFF
+ bool "Sets default behavior for EDD detection to off"
+ depends on EDD
+ default n
+ help
+ Say Y if you want EDD disabled by default, even though it is compiled into the
+ kernel. Say N if you want EDD enabled by default. EDD can be dynamically set
+ using the kernel parameter 'edd={on|skipmbr|off}'.
+
config EFI_VARS
tristate "EFI Variable Support via sysfs"
depends on EFI
--
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