dm: Add a panic_str() function to reduce code size

The printf() in panic() adds about 1.5KB of code size to SPL when compiled
with Thumb-2. Provide a smaller version that does not support printf()-style
arguments and use it in two commonly compiled places.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/serial/serial-uclass.c

@@ -70,7 +70,7 @@ static void serial_find_console_or_panic(void)
 	if (uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) &&
 	    uclass_get_device(UCLASS_SERIAL, INDEX, &dev) &&
 	    (uclass_first_device(UCLASS_SERIAL, &dev) || !dev))
-		panic("No serial driver found");
+		panic_str("No serial driver found");
 #undef INDEX
 	gd->cur_serial_dev = dev;
 }

include/vsprintf.h

@@ -39,9 +39,32 @@ int strict_strtoul(const char *cp, unsigned int base, unsigned long *res);
 unsigned long long simple_strtoull(const char *cp, char **endp,
 					unsigned int base);
 long simple_strtol(const char *cp, char **endp, unsigned int base);
+
+/**
+ * panic() - Print a message and reset/hang
+ *
+ * Prints a message on the console(s) and then resets. If CONFIG_PANIC_HANG is
+ * defined, then it will hang instead of reseting.
+ *
+ * @param fmt:	printf() format string for message, which should not include
+ *		\n, followed by arguments
+ */
 void panic(const char *fmt, ...)
 		__attribute__ ((format (__printf__, 1, 2), noreturn));
 
+/**
+ * panic_str() - Print a message and reset/hang
+ *
+ * Prints a message on the console(s) and then resets. If CONFIG_PANIC_HANG is
+ * defined, then it will hang instead of reseting.
+ *
+ * This function can be used instead of panic() when your board does not
+ * already use printf(), * to keep code size small.
+ *
+ * @param fmt:	string to display, which should not include \n
+ */
+void panic_str(const char *str) __attribute__ ((noreturn));
+
 /**
  * Format a string and place it in a buffer
  *

lib/fdtdec.c

@@ -565,9 +565,11 @@ int fdtdec_prepare_fdt(void)
 {
 	if (!gd->fdt_blob || ((uintptr_t)gd->fdt_blob & 3) ||
 	    fdt_check_header(gd->fdt_blob)) {
-		printf("No valid FDT found - please append one to U-Boot "
+#ifdef CONFIG_SPL_BUILD
-			"binary, use u-boot-dtb.bin or define "
+		puts("Missing DTB\n");
-			"CONFIG_OF_EMBED. For sandbox, use -d <file.dtb>\n");
+#else
+		puts("No valid device tree binary found - please append one to U-Boot binary, use u-boot-dtb.bin or define CONFIG_OF_EMBED. For sandbox, use -d <file.dtb>\n");
+#endif
 		return -1;
 	}
 	return 0;

lib/vsprintf.c

@@ -842,13 +842,11 @@ int sprintf(char *buf, const char *fmt, ...)
 	return i;
 }
 
-void panic(const char *fmt, ...)
+static void panic_finish(void) __attribute__ ((noreturn));
+
+static void panic_finish(void)
 {
-	va_list args;
-	va_start(args, fmt);
-	vprintf(fmt, args);
 	putc('\n');
-	va_end(args);
 #if defined(CONFIG_PANIC_HANG)
 	hang();
 #else
@@ -859,6 +857,21 @@ void panic(const char *fmt, ...)
 		;
 }
 
+void panic_str(const char *str)
+{
+	puts(str);
+	panic_finish();
+}
+
+void panic(const char *fmt, ...)
+{
+	va_list args;
+	va_start(args, fmt);
+	vprintf(fmt, args);
+	va_end(args);
+	panic_finish();
+}
+
 void __assert_fail(const char *assertion, const char *file, unsigned line,
 		   const char *function)
 {