ppc4xx: Add routine to retrieve CPU number

Provide a weak defined routine to retrieve the CPU number for
reference boards that have multiple CPU's.  Default behavior
is the existing single CPU print output.  Reference boards with
multiple CPU's need to provide a board specific routine.
See board/amcc/arches/arches.c for an example.

Signed-off-by: Adam Graham <agraham@amcc.com>
Signed-off-by: Victor Gallardo <vgallardo@amcc.com>
Signed-off-by: Stefan Roese <sr@denx.de>

cpu/ppc4xx/cpu.c

@@ -41,6 +41,18 @@ DECLARE_GLOBAL_DATA_PTR;
 
 void board_reset(void);
 
+/*
+ * To provide an interface to detect CPU number for boards that support
+ * more then one CPU, we implement the "weak" default functions here.
+ *
+ * Returns CPU number
+ */
+int __get_cpu_num(void)
+{
+	return NA_OR_UNKNOWN_CPU;
+}
+int get_cpu_num(void) __attribute__((weak, alias("__get_cpu_num")));
+
 #if defined(CONFIG_405GP) || \
     defined(CONFIG_440EP) || defined(CONFIG_440GR) || \
     defined(CONFIG_440EPX) || defined(CONFIG_440GRX)
@@ -274,8 +286,13 @@ int checkcpu (void)
 #if !defined(CONFIG_IOP480)
 	char addstr[64] = "";
 	sys_info_t sys_info;
+	int cpu_num;
 
-	puts ("CPU:   ");
+	cpu_num = get_cpu_num();
+	if (cpu_num >= 0)
+		printf("CPU%d:  ", cpu_num);
+	else
+		puts("CPU:   ");
 
 	get_sys_info(&sys_info);
 

include/ppc4xx.h

@@ -218,4 +218,7 @@ static inline void set_mcsr(u32 val)
 
 #endif	/* __ASSEMBLY__ */
 
+/* for multi-cpu support */
+#define NA_OR_UNKNOWN_CPU	-1
+
 #endif	/* __PPC4XX_H__ */