diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index aa47be71df4c..37713bcf7778 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -163,6 +163,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. See also Documentation/power/pm.txt, pci=noacpi + acpi_rsdp= [ACPI,EFI,KEXEC] + Pass the RSDP address to the kernel, mostly used + on machines running EFI runtime service to boot the + second kernel for kdump. + acpi_apic_instance= [ACPI, IOAPIC] Format: 2: use 2nd APIC table, if available diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index 52ca9649d769..27cd1408f6d8 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -237,8 +237,23 @@ void acpi_os_vprintf(const char *fmt, va_list args) #endif } +#ifdef CONFIG_KEXEC +static unsigned long acpi_rsdp; +static int __init setup_acpi_rsdp(char *arg) +{ + acpi_rsdp = simple_strtoul(arg, NULL, 16); + return 0; +} +early_param("acpi_rsdp", setup_acpi_rsdp); +#endif + acpi_physical_address __init acpi_os_get_root_pointer(void) { +#ifdef CONFIG_KEXEC + if (acpi_rsdp) + return acpi_rsdp; +#endif + if (efi_enabled) { if (efi.acpi20 != EFI_INVALID_TABLE_ADDR) return efi.acpi20;