2 files changed, 20 insertions, 0 deletions

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: <int>
                         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;