From cff75e0b6fe835800f8e08a32d731119cd9e3b79 Mon Sep 17 00:00:00 2001
From: Daniel Thompson <daniel.thompson@linaro.org>
Date: Mon, 8 May 2017 15:56:57 -0700
Subject: initramfs: provide a way to ignore image provided by bootloader

Many "embedded" architectures provide CMDLINE_FORCE to allow the kernel
to override the command line provided by an inflexible bootloader.
However there is currrently no way for the kernel to override the
initramfs image provided by the bootloader meaning there are still ways
for bootloaders to make things difficult for us.

Fix this by introducing INITRAMFS_FORCE which can prevent the kernel
from loading the bootloader supplied image.

We use CMDLINE_FORCE (and its friend CMDLINE_EXTEND) to imply that the
system has an inflexible bootloader.  This allow us to avoid presenting
this config option to users of systems where inflexible bootloaders
aren't usually a problem.

Link: http://lkml.kernel.org/r/20170217121940.30126-1-daniel.thompson@linaro.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 init/initramfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'init')

diff --git a/init/initramfs.c b/init/initramfs.c
index 8daf7ac6c7e2..9d180273ee8c 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -613,7 +613,7 @@ static int __init populate_rootfs(void)
 	if (err)
 		panic("%s", err); /* Failed to decompress INTERNAL initramfs */
 	/* If available load the bootloader supplied initrd */
-	if (initrd_start) {
+	if (initrd_start && !IS_ENABLED(CONFIG_INITRAMFS_FORCE)) {
 #ifdef CONFIG_BLK_DEV_RAM
 		int fd;
 		printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
-- 
cgit v1.2.3