| /* |
| * 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> |
| |
| typedef int (*out_func_t)(int c, void *ctx); |
| |
| static void _printk_dec_ulong(out_func_t out, void *ctx, |
| const unsigned long num, int pad_zero, |
| int min_width); |
| static void _printk_hex_ulong(out_func_t out, void *ctx, |
| const unsigned long num, int pad_zero, |
| int min_width); |
| |
| /** |
| * @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 |
| */ |
| void _vprintk(out_func_t out, void *ctx, const char *fmt, va_list ap) |
| { |
| int might_format = 0; /* 1 if encountered a '%' */ |
| int pad_zero = 0; |
| int min_width = -1; |
| |
| /* fmt has already been adjusted if needed */ |
| |
| while (*fmt) { |
| if (!might_format) { |
| if (*fmt != '%') { |
| out((int)*fmt, ctx); |
| } else { |
| might_format = 1; |
| min_width = -1; |
| pad_zero = 0; |
| } |
| } else { |
| switch (*fmt) { |
| case '0': |
| if (min_width < 0 && pad_zero == 0) { |
| pad_zero = 1; |
| goto still_might_format; |
| } |
| /* Fall through */ |
| case '1' ... '9': |
| if (min_width < 0) { |
| min_width = *fmt - '0'; |
| } else { |
| min_width = 10 * min_width + *fmt - '0'; |
| } |
| goto still_might_format; |
| 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) { |
| out((int)'-', ctx); |
| d = -d; |
| min_width--; |
| } |
| _printk_dec_ulong(out, ctx, d, pad_zero, |
| min_width); |
| break; |
| } |
| case 'u': { |
| unsigned long u = va_arg( |
| ap, unsigned long); |
| _printk_dec_ulong(out, ctx, u, pad_zero, |
| min_width); |
| break; |
| } |
| case 'p': |
| out('0', ctx); |
| out('x', ctx); |
| /* left-pad pointers with zeros */ |
| pad_zero = 1; |
| min_width = 8; |
| /* Fall through */ |
| case 'x': |
| case 'X': { |
| unsigned long x = va_arg( |
| ap, unsigned long); |
| _printk_hex_ulong(out, ctx, x, pad_zero, |
| min_width); |
| break; |
| } |
| case 's': { |
| char *s = va_arg(ap, char *); |
| |
| while (*s) |
| out((int)(*s++), ctx); |
| break; |
| } |
| case 'c': { |
| int c = va_arg(ap, int); |
| |
| out(c, ctx); |
| break; |
| } |
| case '%': { |
| out((int)'%', ctx); |
| break; |
| } |
| default: |
| out((int)'%', ctx); |
| out((int)*fmt, ctx); |
| break; |
| } |
| might_format = 0; |
| } |
| still_might_format: |
| ++fmt; |
| } |
| } |
| |
| struct out_context { |
| int count; |
| }; |
| |
| static int char_out(int c, struct out_context *ctx) |
| { |
| ctx->count++; |
| return _char_out(c); |
| } |
| |
| /** |
| * @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 Number of characters printed |
| */ |
| int printk(const char *fmt, ...) |
| { |
| struct out_context ctx = { 0 }; |
| va_list ap; |
| |
| va_start(ap, fmt); |
| _vprintk((out_func_t)char_out, &ctx, fmt, ap); |
| va_end(ap); |
| |
| return ctx.count; |
| } |
| |
| /** |
| * @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(out_func_t out, void *ctx, |
| const unsigned long num, int pad_zero, |
| int min_width) |
| { |
| int size = sizeof(num) * 2; |
| int found_largest_digit = 0; |
| int remaining = 8; /* 8 digits max */ |
| |
| for (; size; size--) { |
| char nibble = (num >> ((size - 1) << 2) & 0xf); |
| |
| if (nibble || found_largest_digit || size == 1) { |
| found_largest_digit = 1; |
| nibble += nibble > 9 ? 87 : 48; |
| out((int)nibble, ctx); |
| continue; |
| } |
| |
| if (remaining-- <= min_width) { |
| out((int)(pad_zero ? '0' : ' '), ctx); |
| } |
| } |
| } |
| |
| /** |
| * @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(out_func_t out, void *ctx, |
| const unsigned long num, int pad_zero, |
| int min_width) |
| { |
| unsigned long pos = 999999999; |
| unsigned long remainder = num; |
| int found_largest_digit = 0; |
| int remaining = 10; /* 10 digits max */ |
| |
| /* make sure we don't skip if value is zero */ |
| if (min_width <= 0) { |
| min_width = 1; |
| } |
| |
| while (pos >= 9) { |
| if (found_largest_digit || remainder > pos) { |
| found_largest_digit = 1; |
| out((int)((remainder / (pos + 1)) + 48), ctx); |
| } else if (remaining <= min_width) { |
| out((int)(pad_zero ? '0' : ' '), ctx); |
| } |
| remaining--; |
| remainder %= (pos + 1); |
| pos /= 10; |
| } |
| out((int)(remainder + 48), ctx); |
| } |
| |
| struct str_context { |
| char *str; |
| int max; |
| int count; |
| }; |
| |
| static int str_out(int c, struct str_context *ctx) |
| { |
| if (!ctx->str || ctx->count >= ctx->max) { |
| ctx->count++; |
| return c; |
| } |
| |
| if (ctx->count == ctx->max - 1) { |
| ctx->str[ctx->count++] = '\0'; |
| } else { |
| ctx->str[ctx->count++] = c; |
| } |
| |
| return c; |
| } |
| |
| int snprintk(char *str, size_t size, const char *fmt, ...) |
| { |
| struct str_context ctx = { str, size, 0 }; |
| va_list ap; |
| |
| va_start(ap, fmt); |
| _vprintk((out_func_t)str_out, &ctx, fmt, ap); |
| va_end(ap); |
| |
| if (ctx.count < ctx.max) { |
| str[ctx.count] = '\0'; |
| } |
| |
| return ctx.count; |
| } |
| |
| int vsnprintk(char *str, size_t size, const char *fmt, va_list ap) |
| { |
| struct str_context ctx = { str, size, 0 }; |
| |
| _vprintk((out_func_t)str_out, &ctx, fmt, ap); |
| |
| if (ctx.count < ctx.max) { |
| str[ctx.count] = '\0'; |
| } |
| |
| return ctx.count; |
| } |