x86: Split sc520 memory sizing versus reporting

This patch allows the low-level assembler boot-strap to obtain the RAM
size without calling the destructive 'sizer' routine. This allows
boot-strapping from a U-Boot image loaded in RAM

Signed-off-by: Graeme Russ <graeme.russ@gmail.com>
diff --git a/arch/i386/cpu/start.S b/arch/i386/cpu/start.S
index 25d32e6..1980f1a 100644
--- a/arch/i386/cpu/start.S
+++ b/arch/i386/cpu/start.S
@@ -63,6 +63,11 @@
 	jmp     mem_init
 mem_init_ret:
 
+	/* fetch memory size (into %eax) */
+	mov	$get_mem_size_ret, %ebp
+	jmp     get_mem_size
+get_mem_size_ret:
+
 	/* Check we have enough memory for stack */
 	movl	$CONFIG_SYS_STACK_SIZE, %ecx
 	cmpl	%ecx, %eax