u-boot/lib/tiny-printf.c
Simon South 9b3fbb2b43 tiny-printf: Support vsnprintf()
Add a simple implementation of this function, to allow logging to be
enabled in the SPL or TPL for systems that rely on the tiny printf()
implementation.

To keep the code size small,

- The function is built only when logging is enabled, as it
  (currently) is not needed otherwise; and
- Like the existing implementation of snprintf(), its buffer-size
  parameter is ignored.

Signed-off-by: Simon South <simon@simonsouth.net>
2019-10-31 07:22:53 -04:00

400 lines
7.3 KiB
C

// SPDX-License-Identifier: LGPL-2.1+
/*
* Tiny printf version for SPL
*
* Copied from:
* http://www.sparetimelabs.com/printfrevisited/printfrevisited.php
*
* Copyright (C) 2004,2008 Kustaa Nyholm
*/
#include <common.h>
#include <stdarg.h>
#include <serial.h>
#include <linux/ctype.h>
struct printf_info {
char *bf; /* Digit buffer */
char zs; /* non-zero if a digit has been written */
char *outstr; /* Next output position for sprintf() */
/* Output a character */
void (*putc)(struct printf_info *info, char ch);
};
static void out(struct printf_info *info, char c)
{
*info->bf++ = c;
}
static void out_dgt(struct printf_info *info, char dgt)
{
out(info, dgt + (dgt < 10 ? '0' : 'a' - 10));
info->zs = 1;
}
static void div_out(struct printf_info *info, unsigned long *num,
unsigned long div)
{
unsigned char dgt = 0;
while (*num >= div) {
*num -= div;
dgt++;
}
if (info->zs || dgt > 0)
out_dgt(info, dgt);
}
#ifdef CONFIG_SPL_NET_SUPPORT
static void string(struct printf_info *info, char *s)
{
char ch;
while ((ch = *s++))
out(info, ch);
}
static const char hex_asc[] = "0123456789abcdef";
#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
static inline char *pack_hex_byte(char *buf, u8 byte)
{
*buf++ = hex_asc_hi(byte);
*buf++ = hex_asc_lo(byte);
return buf;
}
static void mac_address_string(struct printf_info *info, u8 *addr,
bool separator)
{
/* (6 * 2 hex digits), 5 colons and trailing zero */
char mac_addr[6 * 3];
char *p = mac_addr;
int i;
for (i = 0; i < 6; i++) {
p = pack_hex_byte(p, addr[i]);
if (separator && i != 5)
*p++ = ':';
}
*p = '\0';
string(info, mac_addr);
}
static char *put_dec_trunc(char *buf, unsigned int q)
{
unsigned int d3, d2, d1, d0;
d1 = (q >> 4) & 0xf;
d2 = (q >> 8) & 0xf;
d3 = (q >> 12);
d0 = 6 * (d3 + d2 + d1) + (q & 0xf);
q = (d0 * 0xcd) >> 11;
d0 = d0 - 10 * q;
*buf++ = d0 + '0'; /* least significant digit */
d1 = q + 9 * d3 + 5 * d2 + d1;
if (d1 != 0) {
q = (d1 * 0xcd) >> 11;
d1 = d1 - 10 * q;
*buf++ = d1 + '0'; /* next digit */
d2 = q + 2 * d2;
if ((d2 != 0) || (d3 != 0)) {
q = (d2 * 0xd) >> 7;
d2 = d2 - 10 * q;
*buf++ = d2 + '0'; /* next digit */
d3 = q + 4 * d3;
if (d3 != 0) {
q = (d3 * 0xcd) >> 11;
d3 = d3 - 10 * q;
*buf++ = d3 + '0'; /* next digit */
if (q != 0)
*buf++ = q + '0'; /* most sign. digit */
}
}
}
return buf;
}
static void ip4_addr_string(struct printf_info *info, u8 *addr)
{
/* (4 * 3 decimal digits), 3 dots and trailing zero */
char ip4_addr[4 * 4];
char temp[3]; /* hold each IP quad in reverse order */
char *p = ip4_addr;
int i, digits;
for (i = 0; i < 4; i++) {
digits = put_dec_trunc(temp, addr[i]) - temp;
/* reverse the digits in the quad */
while (digits--)
*p++ = temp[digits];
if (i != 3)
*p++ = '.';
}
*p = '\0';
string(info, ip4_addr);
}
#endif
/*
* Show a '%p' thing. A kernel extension is that the '%p' is followed
* by an extra set of characters that are extended format
* specifiers.
*
* Right now we handle:
*
* - 'M' For a 6-byte MAC address, it prints the address in the
* usual colon-separated hex notation.
* - 'm' Same as above except there is no colon-separator.
* - 'I4'for IPv4 addresses printed in the usual way (dot-separated
* decimal).
*/
static void pointer(struct printf_info *info, const char *fmt, void *ptr)
{
#ifdef DEBUG
unsigned long num = (uintptr_t)ptr;
unsigned long div;
#endif
switch (*fmt) {
#ifdef DEBUG
case 'a':
switch (fmt[1]) {
case 'p':
default:
num = *(phys_addr_t *)ptr;
break;
}
break;
#endif
#ifdef CONFIG_SPL_NET_SUPPORT
case 'm':
return mac_address_string(info, ptr, false);
case 'M':
return mac_address_string(info, ptr, true);
case 'I':
if (fmt[1] == '4')
return ip4_addr_string(info, ptr);
#endif
default:
break;
}
#ifdef DEBUG
div = 1UL << (sizeof(long) * 8 - 4);
for (; div; div /= 0x10)
div_out(info, &num, div);
#endif
}
static int _vprintf(struct printf_info *info, const char *fmt, va_list va)
{
char ch;
char *p;
unsigned long num;
char buf[12];
unsigned long div;
while ((ch = *(fmt++))) {
if (ch != '%') {
info->putc(info, ch);
} else {
bool lz = false;
int width = 0;
bool islong = false;
ch = *(fmt++);
if (ch == '-')
ch = *(fmt++);
if (ch == '0') {
ch = *(fmt++);
lz = 1;
}
if (ch >= '0' && ch <= '9') {
width = 0;
while (ch >= '0' && ch <= '9') {
width = (width * 10) + ch - '0';
ch = *fmt++;
}
}
if (ch == 'l') {
ch = *(fmt++);
islong = true;
}
info->bf = buf;
p = info->bf;
info->zs = 0;
switch (ch) {
case '\0':
goto abort;
case 'u':
case 'd':
div = 1000000000;
if (islong) {
num = va_arg(va, unsigned long);
if (sizeof(long) > 4)
div *= div * 10;
} else {
num = va_arg(va, unsigned int);
}
if (ch == 'd') {
if (islong && (long)num < 0) {
num = -(long)num;
out(info, '-');
} else if (!islong && (int)num < 0) {
num = -(int)num;
out(info, '-');
}
}
if (!num) {
out_dgt(info, 0);
} else {
for (; div; div /= 10)
div_out(info, &num, div);
}
break;
case 'x':
if (islong) {
num = va_arg(va, unsigned long);
div = 1UL << (sizeof(long) * 8 - 4);
} else {
num = va_arg(va, unsigned int);
div = 0x10000000;
}
if (!num) {
out_dgt(info, 0);
} else {
for (; div; div /= 0x10)
div_out(info, &num, div);
}
break;
case 'c':
out(info, (char)(va_arg(va, int)));
break;
case 's':
p = va_arg(va, char*);
break;
case 'p':
pointer(info, fmt, va_arg(va, void *));
while (isalnum(fmt[0]))
fmt++;
break;
case '%':
out(info, '%');
default:
break;
}
*info->bf = 0;
info->bf = p;
while (*info->bf++ && width > 0)
width--;
while (width-- > 0)
info->putc(info, lz ? '0' : ' ');
if (p) {
while ((ch = *p++))
info->putc(info, ch);
}
}
}
abort:
return 0;
}
#if CONFIG_IS_ENABLED(PRINTF)
static void putc_normal(struct printf_info *info, char ch)
{
putc(ch);
}
int vprintf(const char *fmt, va_list va)
{
struct printf_info info;
info.putc = putc_normal;
return _vprintf(&info, fmt, va);
}
int printf(const char *fmt, ...)
{
struct printf_info info;
va_list va;
int ret;
info.putc = putc_normal;
va_start(va, fmt);
ret = _vprintf(&info, fmt, va);
va_end(va);
return ret;
}
#endif
static void putc_outstr(struct printf_info *info, char ch)
{
*info->outstr++ = ch;
}
int sprintf(char *buf, const char *fmt, ...)
{
struct printf_info info;
va_list va;
int ret;
va_start(va, fmt);
info.outstr = buf;
info.putc = putc_outstr;
ret = _vprintf(&info, fmt, va);
va_end(va);
*info.outstr = '\0';
return ret;
}
#if CONFIG_IS_ENABLED(LOG)
/* Note that size is ignored */
int vsnprintf(char *buf, size_t size, const char *fmt, va_list va)
{
struct printf_info info;
int ret;
info.outstr = buf;
info.putc = putc_outstr;
ret = _vprintf(&info, fmt, va);
*info.outstr = '\0';
return ret;
}
#endif
/* Note that size is ignored */
int snprintf(char *buf, size_t size, const char *fmt, ...)
{
struct printf_info info;
va_list va;
int ret;
va_start(va, fmt);
info.outstr = buf;
info.putc = putc_outstr;
ret = _vprintf(&info, fmt, va);
va_end(va);
*info.outstr = '\0';
return ret;
}