1 files changed, 23 insertions, 0 deletions

diff --git a/arch/i386/kernel/machine_kexec.c b/arch/i386/kernel/machine_kexec.c
index 6b1ae6ba76f0..66c3dc99a655 100644
--- a/arch/i386/kernel/machine_kexec.c
+++ b/arch/i386/kernel/machine_kexec.c
@@ -9,6 +9,7 @@
 #include <linux/mm.h>
 #include <linux/kexec.h>
 #include <linux/delay.h>
+#include <linux/init.h>
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
 #include <asm/tlbflush.h>
@@ -209,3 +210,25 @@ NORET_TYPE void machine_kexec(struct kimage *image)
         rnk = (relocate_new_kernel_t) reboot_code_buffer;
         (*rnk)(page_list, reboot_code_buffer, image->start, cpu_has_pae);
 }
+
+/* crashkernel=size@addr specifies the location to reserve for
+ * a crash kernel.  By reserving this memory we guarantee
+ * that linux never sets it up as a DMA target.
+ * Useful for holding code to do something appropriate
+ * after a kernel panic.
+ */
+static int __init parse_crashkernel(char *arg)
+{
+        unsigned long size, base;
+        size = memparse(arg, &arg);
+        if (*arg == '@') {
+                base = memparse(arg+1, &arg);
+                /* FIXME: Do I want a sanity check
+                 * to validate the memory range?
+                 */
+                crashk_res.start = base;
+                crashk_res.end   = base + size - 1;
+        }
+        return 0;
+}
+early_param("crashkernel", parse_crashkernel);