2 files changed, 18 insertions, 1 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 25d298517104..d25acd51e181 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1396,6 +1396,8 @@ and is between 256 and 4096 characters. It is defined in the file
                         in <PAGE_SIZE> units (needed only for swap files).
                         See  Documentation/power/swsusp-and-swap-files.txt
 
+        retain_initrd   [RAM] Keep initrd memory after extraction
+
         rhash_entries=  [KNL,NET]
                         Set number of hash buckets for route cache
 
diff --git a/init/initramfs.c b/init/initramfs.c
index 4fa0f7977de1..00eff7a11085 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -491,6 +491,17 @@ static char * __init unpack_to_rootfs(char *buf, unsigned len, int check_only)
         return message;
 }
 
+static int __initdata do_retain_initrd;
+
+static int __init retain_initrd_param(char *str)
+{
+        if (*str)
+                return 0;
+        do_retain_initrd = 1;
+        return 1;
+}
+__setup("retain_initrd", retain_initrd_param);
+
 extern char __initramfs_start[], __initramfs_end[];
 #ifdef CONFIG_BLK_DEV_INITRD
 #include <linux/initrd.h>
@@ -501,7 +512,11 @@ static void __init free_initrd(void)
 #ifdef CONFIG_KEXEC
         unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
         unsigned long crashk_end   = (unsigned long)__va(crashk_res.end);
+#endif
+        if (do_retain_initrd)
+                goto skip;
 
+#ifdef CONFIG_KEXEC
         /*
          * If the initrd region is overlapped with crashkernel reserved region,
          * free only memory that is not part of crashkernel region.
@@ -519,7 +534,7 @@ static void __init free_initrd(void)
         } else
 #endif
                 free_initrd_mem(initrd_start, initrd_end);
-
+skip:
         initrd_start = 0;
         initrd_end = 0;
 }