printf: Partially implement floating point support.

src/printf.c

@@ -1,5 +1,7 @@
 #include "global.h"
 
+//#define WITH_FLOAT  // this is busted still
+
 #include <string.h>
 
 uint32_t parse_int(const char *src, int b, int width)
@@ -25,7 +27,7 @@ uint32_t parse_int(const char *src, int b, int width)
 			val += *src - 'A' + 10;
 		else if (*src >= '0' && *src <= '9')
 			val += *src - '0';
-		else 
+		else
 			break;
 	skip:
 		src++;
@@ -39,11 +41,12 @@ uint32_t parse_int(const char *src, int b, int width)
 }
 
 #ifdef WITH_FLOAT
-static int __print_float(char *buf, int buf_len, float i, int width, int width2)
+static int __print_float(char *buf, int buf_len, double i, int width, int width2)
 {
 	char *s, *p = buf;
 	uint8_t use_width = width;
-	uint8_t use_width2 = width2;
+	double t;
+	double u = i;
 
 	if (i == 0.0f) {
 		s = "0.0\0";
@@ -60,13 +63,13 @@ static int __print_float(char *buf, int buf_len, float i, int width, int width2)
 	*s = '\0';
 
 	while (i != 0.0f && (!use_width || (width > 0))) {
-		t = (unsigned int) u % 10.0f;
+		t = u % 10.0f;
 		*--s = (char)(t + '0');
 		u /= 10.0f;
 		width--;
 	}
 
-	
+
 almost:
 	while (width > 0) {
 		*buf++ = '0';
@@ -74,7 +77,7 @@ almost:
 	}
 	strcpy(buf, s);
 
-	return strlen(p);	
+	return strlen(p);
 }
 #endif
 
@@ -83,7 +86,7 @@ static int __print_int(char *buf, int buf_len, int i, int base, int sign, int wi
 	char *s, *p = buf;
 	unsigned int u = (unsigned int) i;
 	uint8_t use_width;
-	int t;	
+	int t;
 
 	use_width = width;
 
@@ -149,7 +152,7 @@ int mcu_vsnprintf(char *str, size_t size, const char *format, va_list ap)
 		if (*format == 'l') {
 			format++;
 			// XXX handle LONG?
-		} 
+		}
 		switch(*format) {
 		case 'c': { /* Character */
 			char tmp = va_arg(ap, int);
@@ -158,7 +161,7 @@ int mcu_vsnprintf(char *str, size_t size, const char *format, va_list ap)
 			break;
 		}
 		case 'u': { /* Unsigned integer */
-			uint8_t tmp = __print_int(str, size-len, 
+			uint8_t tmp = __print_int(str, size-len,
 					     va_arg(ap, unsigned int),
 					     10, 0, width);
 			str += tmp;
@@ -166,16 +169,16 @@ int mcu_vsnprintf(char *str, size_t size, const char *format, va_list ap)
 			break;
 		}
 		case 'd': { /* Signed integer */
-			uint8_t tmp = __print_int(str, size-len, 
+			uint8_t tmp = __print_int(str, size-len,
 					     va_arg(ap, int),
 					     10, 1, width);
 			str += tmp;
 			len += tmp;
 			break;
-		} 
+		}
 		case 'p': { /* Pointer */
 			width = 8;
-			uint8_t tmp = __print_int(str, size-len, 
+			uint8_t tmp = __print_int(str, size-len,
 					     va_arg(ap, unsigned long),
 					     16, 1, width);
 			str += tmp;
@@ -201,7 +204,7 @@ int mcu_vsnprintf(char *str, size_t size, const char *format, va_list ap)
 						  16, 0, width);
 				str += tmp;
 				len += tmp;
-				
+
 				if (i+1 < MAC_ADDR_LEN) {
 					*(str++) = ':';
 					len++;
@@ -234,7 +237,18 @@ int mcu_vsnprintf(char *str, size_t size, const char *format, va_list ap)
 				len++;
 			}
 			break;
-		} 
+		}
+#ifdef WITH_FLOAT
+		case 'f': { /* Floating point */
+			uint8_t tmp = __print_float(str, size-len,
+					     va_arg(ap, double),
+						    width, width);
+			str += tmp;
+			len += tmp;
+			break;
+
+		}
+#endif
 		default: {
 			// char *ptr = va_arg(ap, char *);
 			// XXX insert error into output?