xref: /openbmc/u-boot/lib/tiny-printf.c (revision 6e87ae1c)
1 /*
2  * Tiny printf version for SPL
3  *
4  * Copied from:
5  * http://www.sparetimelabs.com/printfrevisited/printfrevisited.php
6  *
7  * Copyright (C) 2004,2008  Kustaa Nyholm
8  *
9  * SPDX-License-Identifier:	LGPL-2.1+
10  */
11 
12 #include <common.h>
13 #include <stdarg.h>
14 #include <serial.h>
15 #include <linux/ctype.h>
16 
17 struct printf_info {
18 	char *bf;	/* Digit buffer */
19 	char zs;	/* non-zero if a digit has been written */
20 	char *outstr;	/* Next output position for sprintf() */
21 
22 	/* Output a character */
23 	void (*putc)(struct printf_info *info, char ch);
24 };
25 
26 static void putc_normal(struct printf_info *info, char ch)
27 {
28 	putc(ch);
29 }
30 
31 static void out(struct printf_info *info, char c)
32 {
33 	*info->bf++ = c;
34 }
35 
36 static void out_dgt(struct printf_info *info, char dgt)
37 {
38 	out(info, dgt + (dgt < 10 ? '0' : 'a' - 10));
39 	info->zs = 1;
40 }
41 
42 static void div_out(struct printf_info *info, unsigned long *num,
43 		    unsigned long div)
44 {
45 	unsigned char dgt = 0;
46 
47 	while (*num >= div) {
48 		*num -= div;
49 		dgt++;
50 	}
51 
52 	if (info->zs || dgt > 0)
53 		out_dgt(info, dgt);
54 }
55 
56 #ifdef CONFIG_SPL_NET_SUPPORT
57 static void string(struct printf_info *info, char *s)
58 {
59 	char ch;
60 
61 	while ((ch = *s++))
62 		out(info, ch);
63 }
64 
65 static const char hex_asc[] = "0123456789abcdef";
66 #define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
67 #define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
68 
69 static inline char *pack_hex_byte(char *buf, u8 byte)
70 {
71 	*buf++ = hex_asc_hi(byte);
72 	*buf++ = hex_asc_lo(byte);
73 	return buf;
74 }
75 
76 static void mac_address_string(struct printf_info *info, u8 *addr,
77 				bool separator)
78 {
79 	/* (6 * 2 hex digits), 5 colons and trailing zero */
80 	char mac_addr[6 * 3];
81 	char *p = mac_addr;
82 	int i;
83 
84 	for (i = 0; i < 6; i++) {
85 		p = pack_hex_byte(p, addr[i]);
86 		if (separator && i != 5)
87 			*p++ = ':';
88 	}
89 	*p = '\0';
90 
91 	string(info, mac_addr);
92 }
93 
94 static char *put_dec_trunc(char *buf, unsigned int q)
95 {
96 	unsigned int d3, d2, d1, d0;
97 	d1 = (q >> 4) & 0xf;
98 	d2 = (q >> 8) & 0xf;
99 	d3 = (q >> 12);
100 
101 	d0 = 6 * (d3 + d2 + d1) + (q & 0xf);
102 	q = (d0 * 0xcd) >> 11;
103 	d0 = d0 - 10 * q;
104 	*buf++ = d0 + '0'; /* least significant digit */
105 	d1 = q + 9 * d3 + 5 * d2 + d1;
106 	if (d1 != 0) {
107 		q = (d1 * 0xcd) >> 11;
108 		d1 = d1 - 10 * q;
109 		*buf++ = d1 + '0'; /* next digit */
110 
111 		d2 = q + 2 * d2;
112 		if ((d2 != 0) || (d3 != 0)) {
113 			q = (d2 * 0xd) >> 7;
114 			d2 = d2 - 10 * q;
115 			*buf++ = d2 + '0'; /* next digit */
116 
117 			d3 = q + 4 * d3;
118 			if (d3 != 0) {
119 				q = (d3 * 0xcd) >> 11;
120 				d3 = d3 - 10 * q;
121 				*buf++ = d3 + '0';  /* next digit */
122 				if (q != 0)
123 					*buf++ = q + '0'; /* most sign. digit */
124 			}
125 		}
126 	}
127 	return buf;
128 }
129 
130 static void ip4_addr_string(struct printf_info *info, u8 *addr)
131 {
132 	/* (4 * 3 decimal digits), 3 dots and trailing zero */
133 	char ip4_addr[4 * 4];
134 	char temp[3];	/* hold each IP quad in reverse order */
135 	char *p = ip4_addr;
136 	int i, digits;
137 
138 	for (i = 0; i < 4; i++) {
139 		digits = put_dec_trunc(temp, addr[i]) - temp;
140 		/* reverse the digits in the quad */
141 		while (digits--)
142 			*p++ = temp[digits];
143 		if (i != 3)
144 			*p++ = '.';
145 	}
146 	*p = '\0';
147 
148 	string(info, ip4_addr);
149 }
150 #endif
151 
152 /*
153  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
154  * by an extra set of characters that are extended format
155  * specifiers.
156  *
157  * Right now we handle:
158  *
159  * - 'M' For a 6-byte MAC address, it prints the address in the
160  *       usual colon-separated hex notation.
161  * - 'm' Same as above except there is no colon-separator.
162  * - 'I4'for IPv4 addresses printed in the usual way (dot-separated
163  *       decimal).
164  */
165 
166 static void pointer(struct printf_info *info, const char *fmt, void *ptr)
167 {
168 #ifdef DEBUG
169 	unsigned long num = (uintptr_t)ptr;
170 	unsigned long div;
171 #endif
172 
173 	switch (*fmt) {
174 #ifdef DEBUG
175 	case 'a':
176 
177 		switch (fmt[1]) {
178 		case 'p':
179 		default:
180 			num = *(phys_addr_t *)ptr;
181 			break;
182 		}
183 		break;
184 #endif
185 #ifdef CONFIG_SPL_NET_SUPPORT
186 	case 'm':
187 		return mac_address_string(info, ptr, false);
188 	case 'M':
189 		return mac_address_string(info, ptr, true);
190 	case 'I':
191 		if (fmt[1] == '4')
192 			return ip4_addr_string(info, ptr);
193 #endif
194 	default:
195 		break;
196 	}
197 #ifdef DEBUG
198 	div = 1UL << (sizeof(long) * 8 - 4);
199 	for (; div; div /= 0x10)
200 		div_out(info, &num, div);
201 #endif
202 }
203 
204 static int _vprintf(struct printf_info *info, const char *fmt, va_list va)
205 {
206 	char ch;
207 	char *p;
208 	unsigned long num;
209 	char buf[12];
210 	unsigned long div;
211 
212 	while ((ch = *(fmt++))) {
213 		if (ch != '%') {
214 			info->putc(info, ch);
215 		} else {
216 			bool lz = false;
217 			int width = 0;
218 			bool islong = false;
219 
220 			ch = *(fmt++);
221 			if (ch == '-')
222 				ch = *(fmt++);
223 
224 			if (ch == '0') {
225 				ch = *(fmt++);
226 				lz = 1;
227 			}
228 
229 			if (ch >= '0' && ch <= '9') {
230 				width = 0;
231 				while (ch >= '0' && ch <= '9') {
232 					width = (width * 10) + ch - '0';
233 					ch = *fmt++;
234 				}
235 			}
236 			if (ch == 'l') {
237 				ch = *(fmt++);
238 				islong = true;
239 			}
240 
241 			info->bf = buf;
242 			p = info->bf;
243 			info->zs = 0;
244 
245 			switch (ch) {
246 			case '\0':
247 				goto abort;
248 			case 'u':
249 			case 'd':
250 				div = 1000000000;
251 				if (islong) {
252 					num = va_arg(va, unsigned long);
253 					if (sizeof(long) > 4)
254 						div *= div * 10;
255 				} else {
256 					num = va_arg(va, unsigned int);
257 				}
258 
259 				if (ch == 'd') {
260 					if (islong && (long)num < 0) {
261 						num = -(long)num;
262 						out(info, '-');
263 					} else if (!islong && (int)num < 0) {
264 						num = -(int)num;
265 						out(info, '-');
266 					}
267 				}
268 				if (!num) {
269 					out_dgt(info, 0);
270 				} else {
271 					for (; div; div /= 10)
272 						div_out(info, &num, div);
273 				}
274 				break;
275 			case 'x':
276 				if (islong) {
277 					num = va_arg(va, unsigned long);
278 					div = 1UL << (sizeof(long) * 8 - 4);
279 				} else {
280 					num = va_arg(va, unsigned int);
281 					div = 0x10000000;
282 				}
283 				if (!num) {
284 					out_dgt(info, 0);
285 				} else {
286 					for (; div; div /= 0x10)
287 						div_out(info, &num, div);
288 				}
289 				break;
290 			case 'c':
291 				out(info, (char)(va_arg(va, int)));
292 				break;
293 			case 's':
294 				p = va_arg(va, char*);
295 				break;
296 			case 'p':
297 				pointer(info, fmt, va_arg(va, void *));
298 				while (isalnum(fmt[0]))
299 					fmt++;
300 				break;
301 			case '%':
302 				out(info, '%');
303 			default:
304 				break;
305 			}
306 
307 			*info->bf = 0;
308 			info->bf = p;
309 			while (*info->bf++ && width > 0)
310 				width--;
311 			while (width-- > 0)
312 				info->putc(info, lz ? '0' : ' ');
313 			if (p) {
314 				while ((ch = *p++))
315 					info->putc(info, ch);
316 			}
317 		}
318 	}
319 
320 abort:
321 	return 0;
322 }
323 
324 int vprintf(const char *fmt, va_list va)
325 {
326 	struct printf_info info;
327 
328 	info.putc = putc_normal;
329 	return _vprintf(&info, fmt, va);
330 }
331 
332 int printf(const char *fmt, ...)
333 {
334 	struct printf_info info;
335 
336 	va_list va;
337 	int ret;
338 
339 	info.putc = putc_normal;
340 	va_start(va, fmt);
341 	ret = _vprintf(&info, fmt, va);
342 	va_end(va);
343 
344 	return ret;
345 }
346 
347 static void putc_outstr(struct printf_info *info, char ch)
348 {
349 	*info->outstr++ = ch;
350 }
351 
352 int sprintf(char *buf, const char *fmt, ...)
353 {
354 	struct printf_info info;
355 	va_list va;
356 	int ret;
357 
358 	va_start(va, fmt);
359 	info.outstr = buf;
360 	info.putc = putc_outstr;
361 	ret = _vprintf(&info, fmt, va);
362 	va_end(va);
363 	*info.outstr = '\0';
364 
365 	return ret;
366 }
367 
368 /* Note that size is ignored */
369 int snprintf(char *buf, size_t size, const char *fmt, ...)
370 {
371 	struct printf_info info;
372 	va_list va;
373 	int ret;
374 
375 	va_start(va, fmt);
376 	info.outstr = buf;
377 	info.putc = putc_outstr;
378 	ret = _vprintf(&info, fmt, va);
379 	va_end(va);
380 	*info.outstr = '\0';
381 
382 	return ret;
383 }
384 
385 void __assert_fail(const char *assertion, const char *file, unsigned line,
386 		   const char *function)
387 {
388 	/* This will not return */
389 	printf("%s:%u: %s: Assertion `%s' failed.", file, line, function,
390 	       assertion);
391 	hang();
392 }
393