This is a patch for testing that will not go to any git tree. Add a early kernel parameter to set CMOS RTC Not Present bit in acpi_gbl_FADT variable for testing. Use acpi_no_cmos_rtc=1 to enable this bit to block rtc cmos interface. Signed-off-by: Lee, Chun-Yi <jlee@xxxxxxxx> --- arch/x86/kernel/acpi/boot.c | 17 +++++++++++++++++ 1 files changed, 17 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 6c0b43b..64925dd 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -83,6 +83,8 @@ static u64 acpi_lapic_addr __initdata = APIC_DEFAULT_PHYS_BASE; #warning ACPI uses CMPXCHG, i486 and later hardware #endif +static bool acpi_no_cmos_rtc; + /* -------------------------------------------------------------------------- Boot-time Configuration -------------------------------------------------------------------------- */ @@ -1531,6 +1533,13 @@ int __init acpi_boot_init(void) */ acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt); + /* Dummy NO_CMOS_RTC enable option to fake out RTC CMOS */ + if (acpi_no_cmos_rtc) { + acpi_gbl_FADT.header.revision = 5; + acpi_gbl_FADT.boot_flags |= ACPI_FADT_NO_CMOS_RTC; + pr_info("acpi: Set NO_CMOS_RTC bit in FADT for testing\n"); + } + /* * Process the Multiple APIC Description Table (MADT), if present */ @@ -1673,3 +1682,11 @@ void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size) e820_add_region(addr, size, E820_ACPI); update_e820(); } + +/* Dummy NO_CMOS_RTC enable option to fake out RTC CMOS */ +static int __init setup_acpi_no_cmos_rtc(char *arg) +{ + acpi_no_cmos_rtc = true; + return 0; +} +early_param("acpi_no_cmos_rtc", setup_acpi_no_cmos_rtc); -- 1.6.4.2 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html