sh: Provide a 29/32-bit physical hint for bootloaders.

Shoves a magic word in to the empty_zero_page section for the
bootloader to work out whether to start the kernel in 29-bit
or 32-bit mode.

[ Renesas CPUs already take care of the initial PMB mappings entirely
  in hardware and decide on 29-bit/32-bit physical depending on which
  pin powered up the CPU, so this is mostly for ST parts. -- PFM ].

Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/arch/sh/kernel/head_32.S b/arch/sh/kernel/head_32.S
index 3338239717f1..d67d7ed09f22 100644
--- a/arch/sh/kernel/head_32.S
+++ b/arch/sh/kernel/head_32.S
@@ -32,7 +32,11 @@ ENTRY(empty_zero_page)
         .long   1               /* LOADER_TYPE */
         .long   0x00360000      /* INITRD_START */
         .long   0x000a0000      /* INITRD_SIZE */
-        .long   0
+#ifdef CONFIG_32BIT
+        .long   0x53453f00 + 32 /* "SE?" = 32 bit */
+#else
+        .long   0x53453f00 + 29 /* "SE?" = 29 bit */
+#endif
 1:
         .skip   PAGE_SIZE - empty_zero_page - 1b