From: Tim Gardner 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. Signed-off-by: Tim Gardner Signed-off-by: Matt Domsch Cc: "H. Peter Anvin" Cc: "Randy.Dunlap" Signed-off-by: Andrew Morton --- Documentation/kernel-parameters.txt | 3 +-- arch/x86/boot/edd.c | 10 +++++++++- drivers/firmware/Kconfig | 9 +++++++++ 3 files changed, 19 insertions(+), 3 deletions(-) diff -puN Documentation/kernel-parameters.txt~edd-add-default-mode-config_edd_off=n-override-with-edd=onoff Documentation/kernel-parameters.txt --- a/Documentation/kernel-parameters.txt~edd-add-default-mode-config_edd_off=n-override-with-edd=onoff +++ a/Documentation/kernel-parameters.txt @@ -635,8 +635,7 @@ and is between 256 and 4096 characters. eata= [HW,SCSI] edd= [EDD] - Format: {"of[f]" | "sk[ipmbr]"} - See comment in arch/i386/boot/edd.S + Format: {"off" | "on" | "sk[ipmbr]"} eisa_irq_edge= [PARISC,HW] See header of drivers/parisc/eisa.c. diff -puN arch/x86/boot/edd.c~edd-add-default-mode-config_edd_off=n-override-with-edd=onoff arch/x86/boot/edd.c --- a/arch/x86/boot/edd.c~edd-add-default-mode-config_edd_off=n-override-with-edd=onoff +++ a/arch/x86/boot/edd.c @@ -128,17 +128,25 @@ 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 -puN drivers/firmware/Kconfig~edd-add-default-mode-config_edd_off=n-override-with-edd=onoff drivers/firmware/Kconfig --- a/drivers/firmware/Kconfig~edd-add-default-mode-config_edd_off=n-override-with-edd=onoff +++ a/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 _