spl, common, serial: build SPL without serial support

This patch enables building SPL without
CONFIG_SPL_SERIAL_SUPPORT support.

Signed-off-by: Heiko Schocher <hs@denx.de>
[trini: Ensure we build arch/arm/imx-common on mx28]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 6f30098..ab0e9ce 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -78,7 +78,7 @@
 libs-y += arch/arm/lib/
 
 ifeq ($(CONFIG_SPL_BUILD),y)
-ifneq (,$(CONFIG_MX23)$(CONFIG_MX35)$(filter $(SOC), mx25 mx27 mx5 mx6 mx31 mx35))
+ifneq (,$(CONFIG_MX23)$(CONFIG_MX28)$(CONFIG_MX35)$(filter $(SOC), mx25 mx27 mx5 mx6 mx31 mx35))
 libs-y += arch/arm/imx-common/
 endif
 else
diff --git a/arch/arm/lib/interrupts.c b/arch/arm/lib/interrupts.c
index 06f4679..ec3fb77 100644
--- a/arch/arm/lib/interrupts.c
+++ b/arch/arm/lib/interrupts.c
@@ -123,8 +123,8 @@
 
 void show_regs (struct pt_regs *regs)
 {
-	unsigned long flags;
-	const char *processor_modes[] = {
+	unsigned long __maybe_unused flags;
+	const char __maybe_unused *processor_modes[] = {
 	"USER_26",	"FIQ_26",	"IRQ_26",	"SVC_26",
 	"UK4_26",	"UK5_26",	"UK6_26",	"UK7_26",
 	"UK8_26",	"UK9_26",	"UK10_26",	"UK11_26",
diff --git a/arch/arm/mach-at91/arm926ejs/cpu.c b/arch/arm/mach-at91/arm926ejs/cpu.c
index da1d359..990c689 100644
--- a/arch/arm/mach-at91/arm926ejs/cpu.c
+++ b/arch/arm/mach-at91/arm926ejs/cpu.c
@@ -42,7 +42,7 @@
 #if defined(CONFIG_DISPLAY_CPUINFO)
 int print_cpuinfo(void)
 {
-	char buf[32];
+	char __maybe_unused buf[32];
 
 	printf("CPU: %s\n", ATMEL_CPU_NAME);
 	printf("Crystal frequency: %8s MHz\n",
diff --git a/arch/arm/mach-at91/spl_at91.c b/arch/arm/mach-at91/spl_at91.c
index a79a9dc..b19f95b 100644
--- a/arch/arm/mach-at91/spl_at91.c
+++ b/arch/arm/mach-at91/spl_at91.c
@@ -123,9 +123,12 @@
 	at91_periph_clk_enable(ATMEL_ID_PIOB);
 	at91_periph_clk_enable(ATMEL_ID_PIOC);
 #endif
+
+#if defined(CONFIG_SPL_SERIAL_SUPPORT)
 	/* init console */
 	at91_seriald_hw_init();
 	preloader_console_init();
+#endif
 
 	mem_init();
 
diff --git a/common/Makefile b/common/Makefile
index 6dc4c89..dc82433 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -251,7 +251,11 @@
 obj-$(CONFIG_SPD_EEPROM) += ddr_spd.o
 obj-$(CONFIG_HWCONFIG) += hwconfig.o
 obj-$(CONFIG_BOUNCE_BUFFER) += bouncebuf.o
+ifdef CONFIG_SPL_BUILD
+obj-$(CONFIG_SPL_SERIAL_SUPPORT) += console.o
+else
 obj-y += console.o
+endif
 obj-$(CONFIG_CROS_EC) += cros_ec.o
 obj-y += dlmalloc.o
 ifdef CONFIG_SYS_MALLOC_F_LEN
diff --git a/common/cli_readline.c b/common/cli_readline.c
index 9a9fb35..c1476e4 100644
--- a/common/cli_readline.c
+++ b/common/cli_readline.c
@@ -597,7 +597,7 @@
 					puts(tab_seq + (col & 07));
 					col += 8 - (col & 07);
 				} else {
-					char buf[2];
+					char __maybe_unused buf[2];
 
 					/*
 					 * Echo input using puts() to force an
diff --git a/common/cli_simple.c b/common/cli_simple.c
index 6c65cc6..00a8d2f 100644
--- a/common/cli_simple.c
+++ b/common/cli_simple.c
@@ -68,7 +68,7 @@
 	/* 1 = waiting for '(' or '{' */
 	/* 2 = waiting for ')' or '}' */
 	/* 3 = waiting for '''  */
-	char *output_start = output;
+	char __maybe_unused *output_start = output;
 
 	debug_parser("[PROCESS_MACROS] INPUT len %zd: \"%s\"\n", strlen(input),
 		     input);
diff --git a/common/image.c b/common/image.c
index 9efacf8..c3616e2 100644
--- a/common/image.c
+++ b/common/image.c
@@ -54,6 +54,10 @@
 #include <u-boot/md5.h>
 #include <time.h>
 #include <image.h>
+
+#ifndef __maybe_unused
+# define __maybe_unused		/* unimplemented */
+#endif
 #endif /* !USE_HOSTCC*/
 
 #include <u-boot/crc.h>
@@ -274,7 +278,7 @@
 
 static void image_print_type(const image_header_t *hdr)
 {
-	const char *os, *arch, *type, *comp;
+	const char __maybe_unused *os, *arch, *type, *comp;
 
 	os = genimg_get_os_name(image_get_os(hdr));
 	arch = genimg_get_arch_name(image_get_arch(hdr));
@@ -299,7 +303,7 @@
 void image_print_contents(const void *ptr)
 {
 	const image_header_t *hdr = (const image_header_t *)ptr;
-	const char *p;
+	const char __maybe_unused *p;
 
 	p = IMAGE_INDENT_STRING;
 	printf("%sImage Name:   %.*s\n", p, IH_NMLEN, image_get_name(hdr));
diff --git a/include/common.h b/include/common.h
index fcc9ae7..5c076d6 100644
--- a/include/common.h
+++ b/include/common.h
@@ -830,11 +830,18 @@
 int	tstc(void);
 
 /* stdout */
+#if defined(CONFIG_SPL_BUILD) && !defined(CONFIG_SPL_SERIAL_SUPPORT)
+#define	putc(...) do { } while (0)
+#define puts(...) do { } while (0)
+#define printf(...) do { } while (0)
+#define vprintf(...) do { } while (0)
+#else
 void	putc(const char c);
 void	puts(const char *s);
 int	printf(const char *fmt, ...)
 		__attribute__ ((format (__printf__, 1, 2)));
 int	vprintf(const char *fmt, va_list args);
+#endif
 
 /* stderr */
 #define eputc(c)		fputc(stderr, c)
diff --git a/include/configs/apf27.h b/include/configs/apf27.h
index a0a26bb..cf13563 100644
--- a/include/configs/apf27.h
+++ b/include/configs/apf27.h
@@ -40,6 +40,7 @@
 #define CONFIG_SPL_LDSCRIPT	"arch/$(ARCH)/cpu/u-boot-spl.lds"
 #define CONFIG_SPL_MAX_SIZE	2048
 #define CONFIG_SPL_TEXT_BASE    0xA0000000
+#define CONFIG_SPL_SERIAL_SUPPORT
 
 /* NAND boot config */
 #define CONFIG_SPL_NAND_SUPPORT
diff --git a/include/configs/mx31pdk.h b/include/configs/mx31pdk.h
index 7e709cd..72d28c9 100644
--- a/include/configs/mx31pdk.h
+++ b/include/configs/mx31pdk.h
@@ -35,6 +35,7 @@
 #define CONFIG_SPL_MAX_SIZE	2048
 #define CONFIG_SPL_NAND_SUPPORT
 #define CONFIG_SPL_LIBGENERIC_SUPPORT
+#define CONFIG_SPL_SERIAL_SUPPORT
 
 #define CONFIG_SPL_TEXT_BASE	0x87dc0000
 #define CONFIG_SYS_TEXT_BASE	0x87e00000
diff --git a/include/configs/mxs.h b/include/configs/mxs.h
index 38b1e93..9d823de 100644
--- a/include/configs/mxs.h
+++ b/include/configs/mxs.h
@@ -55,6 +55,7 @@
 #define CONFIG_SPL_LDSCRIPT	"arch/arm/cpu/arm926ejs/mxs/u-boot-spl.lds"
 #define CONFIG_SPL_LIBCOMMON_SUPPORT
 #define CONFIG_SPL_LIBGENERIC_SUPPORT
+#define CONFIG_SPL_SERIAL_SUPPORT
 #define CONFIG_SPL_GPIO_SUPPORT
 
 /* Memory sizes */
diff --git a/include/configs/tx25.h b/include/configs/tx25.h
index e7b006c..834b616 100644
--- a/include/configs/tx25.h
+++ b/include/configs/tx25.h
@@ -26,6 +26,7 @@
 #define CONFIG_SPL_MAX_SIZE		2048
 #define CONFIG_SPL_NAND_SUPPORT
 #define CONFIG_SPL_LIBGENERIC_SUPPORT
+#define CONFIG_SPL_SERIAL_SUPPORT
 
 #define CONFIG_SPL_TEXT_BASE		0x810c0000
 #define CONFIG_SYS_TEXT_BASE		0x81200000
diff --git a/lib/display_options.c b/lib/display_options.c
index 57fb974..df134cd 100644
--- a/lib/display_options.c
+++ b/lib/display_options.c
@@ -25,7 +25,10 @@
 
 void print_freq(uint64_t freq, const char *s)
 {
-	unsigned long m = 0, n;
+	unsigned long m = 0;
+#if defined(CONFIG_SPL_SERIAL_SUPPORT)
+	unsigned long n;
+#endif
 	uint32_t f;
 	static const char names[] = {'G', 'M', 'K'};
 	unsigned long d = 1e9;
@@ -45,7 +48,9 @@
 	}
 
 	f = do_div(freq, d);
+#if defined(CONFIG_SPL_SERIAL_SUPPORT)
 	n = freq;
+#endif
 
 	/* If there's a remainder, show the first few digits */
 	if (f) {
@@ -58,7 +63,9 @@
 			m = (m / 10) + (m % 100 >= 50);
 	}
 
+#if defined(CONFIG_SPL_SERIAL_SUPPORT)
 	printf("%lu", n);
+#endif
 	if (m)
 		printf(".%ld", m);
 	printf(" %cHz%s", c, s);
@@ -121,9 +128,9 @@
 	} lb;
 	int i;
 #ifdef CONFIG_SYS_SUPPORT_64BIT_DATA
-	uint64_t x;
+	uint64_t __maybe_unused x;
 #else
-	uint32_t x;
+	uint32_t __maybe_unused x;
 #endif
 
 	if (linelen*width > MAX_LINE_LENGTH_BYTES)