| /* |
| * Copyright (c) 2010, 2013-2014 Wind River Systems, Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| /** |
| * @file |
| * @brief Low-level debug output |
| * |
| * Low-level debugging output. Platform installs a character output routine at |
| * init time. If no routine is installed, a nop routine is called. |
| */ |
| |
| #include <misc/printk.h> |
| #include <stdarg.h> |
| #include <toolchain.h> |
| #include <sections.h> |
| |
| static void _printk_dec_ulong(const unsigned long num); |
| static void _printk_hex_ulong(const unsigned long num); |
| |
| /** |
| * @brief Default character output routine that does nothing |
| * @param c Character to swallow |
| * |
| * @return 0 |
| */ |
| static int _nop_char_out(int c) |
| { |
| ARG_UNUSED(c); |
| |
| /* do nothing */ |
| return 0; |
| } |
| |
| int (*_char_out)(int) = _nop_char_out; |
| |
| |
| /** |
| * @brief Install the character output routine for printk |
| * |
| * To be called by the platform's console driver at init time. Installs a |
| * routine that outputs one ASCII character at a time. |
| * @param fn putc routine to install |
| * |
| * @return N/A |
| */ |
| void __printk_hook_install(int (*fn)(int)) |
| { |
| _char_out = fn; |
| } |
| |
| /** |
| * @brief Printk internals |
| * |
| * See printk() for description. |
| * @param fmt Format string |
| * @param ap Variable parameters |
| * |
| * @return N/A |
| */ |
| static inline void _vprintk(const char *fmt, va_list ap) |
| { |
| int might_format = 0; /* 1 if encountered a '%' */ |
| |
| /* fmt has already been adjusted if needed */ |
| |
| while (*fmt) { |
| if (!might_format) { |
| if (*fmt != '%') { |
| _char_out((int)*fmt); |
| } else { |
| might_format = 1; |
| } |
| } else { |
| switch (*fmt) { |
| case 'z': |
| case 'l': |
| case 'h': |
| /* FIXME: do nothing for these modifiers */ |
| goto still_might_format; |
| case 'd': |
| case 'i': { |
| long d = va_arg(ap, long); |
| |
| if (d < 0) { |
| _char_out((int)'-'); |
| d = -d; |
| } |
| _printk_dec_ulong(d); |
| break; |
| } |
| case 'u': { |
| unsigned long u = va_arg( |
| ap, unsigned long); |
| _printk_dec_ulong(u); |
| break; |
| } |
| case 'p': |
| _char_out('0'); |
| _char_out('x'); |
| /* Fall through */ |
| case 'x': |
| case 'X': { |
| unsigned long x = va_arg( |
| ap, unsigned long); |
| _printk_hex_ulong(x); |
| break; |
| } |
| case 's': { |
| char *s = va_arg(ap, char *); |
| |
| while (*s) |
| _char_out((int)(*s++)); |
| break; |
| } |
| case 'c': { |
| int c = va_arg(ap, int); |
| |
| _char_out(c); |
| break; |
| } |
| case '%': { |
| _char_out((int)'%'); |
| break; |
| } |
| default: |
| _char_out((int)'%'); |
| _char_out((int)*fmt); |
| break; |
| } |
| might_format = 0; |
| } |
| still_might_format: |
| ++fmt; |
| } |
| } |
| |
| /** |
| * @brief Output a string |
| * |
| * Output a string on output installed by platform at init time. Some |
| * printf-like formatting is available. |
| * |
| * Available formatting: |
| * - %x/%X: outputs a 32-bit number in ABCDWXYZ format. All eight digits |
| * are printed: if less than 8 characters are needed, leading zeroes |
| * are displayed. |
| * - %s: output a null-terminated string |
| * - %p: pointer, same as %x |
| * - %d/%i/%u: outputs a 32-bit number in unsigned decimal format. |
| * |
| * @param fmt formatted string to output |
| * |
| * @return N/A |
| */ |
| void printk(const char *fmt, ...) |
| { |
| va_list ap; |
| |
| va_start(ap, fmt); |
| _vprintk(fmt, ap); |
| va_end(ap); |
| } |
| |
| /** |
| * @brief Output an unsigned long in hex format |
| * |
| * Output an unsigned long on output installed by platform at init time. Should |
| * be able to handle an unsigned long of any size, 32 or 64 bit. |
| * @param num Number to output |
| * |
| * @return N/A |
| */ |
| static void _printk_hex_ulong(const unsigned long num) |
| { |
| int size = sizeof(num) * 2; |
| |
| for (; size; size--) { |
| char nibble = (num >> ((size - 1) << 2) & 0xf); |
| nibble += nibble > 9 ? 87 : 48; |
| _char_out((int)nibble); |
| } |
| } |
| |
| /** |
| * @brief Output an unsigned long (32-bit) in decimal format |
| * |
| * Output an unsigned long on output installed by platform at init time. Only |
| * works with 32-bit values. |
| * @param num Number to output |
| * |
| * @return N/A |
| */ |
| static void _printk_dec_ulong(const unsigned long num) |
| { |
| unsigned long pos = 999999999; |
| unsigned long remainder = num; |
| int found_largest_digit = 0; |
| |
| while (pos >= 9) { |
| if (found_largest_digit || remainder > pos) { |
| found_largest_digit = 1; |
| _char_out((int)((remainder / (pos + 1)) + 48)); |
| } |
| remainder %= (pos + 1); |
| pos /= 10; |
| } |
| _char_out((int)(remainder + 48)); |
| } |
| |