[PATCH] powerpc: Unify udbg (#2)

This patch unifies udbg for both ppc32 and ppc64 when building the
merged achitecture. xmon now has a single "back end". The powermac udbg
stuff gets enriched with some ADB capabilities and btext output. In
addition, the early_init callback is now called on ppc32 as well,
approx. in the same order as ppc64 regarding device-tree manipulations.
The init sequences of ppc32 and ppc64 are getting closer, I'll unify
them in a later patch.

For now, you can force udbg to the scc using "sccdbg" or to btext using
"btextdbg" on powermacs. I'll implement a cleaner way of forcing udbg
output to something else than the autodetected OF output device in a
later patch.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

include/asm-ppc/btext.h

@@ -17,7 +17,7 @@ extern unsigned long disp_BAT[2];
 extern boot_infos_t disp_bi;
 extern int boot_text_mapped;
 
-extern void init_boot_display(void);
+extern void btext_init(boot_infos_t *bi);
 extern void btext_welcome(void);
 extern void btext_prepare_BAT(void);
 extern void btext_setup_display(int width, int height, int depth, int pitch,

include/asm-ppc/machdep.h

@@ -35,8 +35,10 @@ struct machdep_calls {
 	int		(*get_irq)(struct pt_regs *);
 	
 	/* A general init function, called by ppc_init in init/main.c.
-	   May be NULL. */
+	   May be NULL. DEPRECATED ! */
 	void		(*init)(void);
+	/* For compatibility with merged platforms */
+	void		(*init_early)(void);
 
 	void		(*restart)(char *cmd);
 	void		(*power_off)(void);