[PATCH] powerpc: Refuse to boot a kdump kernel via OF

You can't boot a kdump kernel via OF, not reliably anyway, the kernel being at
32 MB conflicts with the zImage wrapper etc. and it blows up.

It's trivial to check in prom_init though, and this is early enough that we can
actually drop back to OF where a reset-all will get you going again, which is
kinda nice. I think this should go in for 2.6.16.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 7881ec96ef11..ec7153f4d47c 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -2098,6 +2098,10 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4,
          */
         prom_init_stdout();
 
+        /* Bail if this is a kdump kernel. */
+        if (PHYSICAL_START > 0)
+                prom_panic("Error: You can't boot a kdump kernel from OF!\n");
+
         /*
          * Check for an initrd
          */