[PATCH] ppc64 boot: print firmware provided stackpointer

Show firmware provided stackpointer during boot.

This helps to find the "taboo" areas on the various boards.  claim tends to
fail for these memory areas, but some jokers return success anyway.

Use %p to print the load address, its a pointer.

Signed-off-by: Olaf Hering <olh@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --git a/arch/ppc64/boot/crt0.S b/arch/ppc64/boot/crt0.S
index 8bfdeaf..9cc4422 100644 (file)
--- a/arch/ppc64/boot/crt0.S
+++ b/arch/ppc64/boot/crt0.S
@@ -54,5 +54,6 @@ clear_caches:
        sync
        isync
 
+       mr      r6,r1
        b       start
 

diff --git a/arch/ppc64/boot/main.c b/arch/ppc64/boot/main.c
index 3304ed3..c1dc876 100644 (file)
--- a/arch/ppc64/boot/main.c
+++ b/arch/ppc64/boot/main.c
@@ -131,7 +131,7 @@ static unsigned long try_claim(unsigned long size)
        return addr;
 }
 
-void start(unsigned long a1, unsigned long a2, void *promptr)
+void start(unsigned long a1, unsigned long a2, void *promptr, void *sp)
 {
        unsigned long i;
        int len;
@@ -151,7 +151,7 @@ void start(unsigned long a1, unsigned long a2, void *promptr)
        if (getprop(chosen_handle, "stdin", &stdin, sizeof(stdin)) != 4)
                exit();
 
-       printf("\n\rzImage starting: loaded at 0x%lx\n\r", (unsigned long) _start);
+       printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r", _start, sp);
 
        /*
         * The first available claim_base must be above the end of the