sparc32: introduce sparc32_start_kernel called from head_32.S

This gives us a C hook before we call start_kernel()
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

arch/sparc/kernel/head_32.S

@@ -661,16 +661,10 @@ continue_boot:
 		wr	%g3, PSR_ET, %psr
 		WRITE_PAUSE
 
-		/* First we call prom_init() to set up PROMLIB, then
-		 * off to start_kernel().
-		 */
-
+		/* Call sparc32_start_kernel(struct linux_romvec *rp) */
 		sethi	%hi(prom_vector_p), %g5
 		ld	[%g5 + %lo(prom_vector_p)], %o0
-		call	prom_init
-		 nop
-
-		call	start_kernel
+		call	sparc32_start_kernel
 		 nop
 
 		/* We should not get here. */

arch/sparc/kernel/kernel.h

@@ -26,6 +26,9 @@ static inline unsigned long kimage_addr_to_ra(const char *p)
 #endif
 
 #ifdef CONFIG_SPARC32
+/* setup_32.c */
+void sparc32_start_kernel(struct linux_romvec *rp);
+
 /* cpu.c */
 extern void cpu_probe(void);
 

arch/sparc/kernel/setup_32.c

@@ -32,6 +32,7 @@
 #include <linux/cpu.h>
 #include <linux/kdebug.h>
 #include <linux/export.h>
+#include <linux/start_kernel.h>
 
 #include <asm/io.h>
 #include <asm/processor.h>
@@ -244,6 +245,15 @@ struct tt_entry *sparc_ttable;
 
 struct pt_regs fake_swapper_regs;
 
+/* Called from head_32.S - before we have setup anything
+ * in the kernel. Be very careful with what you do here.
+ */
+void __init sparc32_start_kernel(struct linux_romvec *rp)
+{
+	prom_init(rp);
+	start_kernel();
+}
+
 void __init setup_arch(char **cmdline_p)
 {
 	int i;