printk.c

/*
 * BSD 3-Clause License
 *
 * Copyright (c) 2022, d0p1
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
#include <stddef.h>
#include <stdarg.h>
#include <stdint.h>
 
#include <sys/console.h>
 
static inline void
printstr(const char *str)
{
    if (str == NULL)
    {
        printstr("(null)");
        return;
    }
 
    while (*str != '\0')
    {
        console_putchar(*str++);
    }
}
 
static inline void
printuint(uintptr_t u, int base)
{
    static const char digits[] = "0123456789abcdef";
    static char buff[20];
    int idx;
 
    idx = 0;
    do
    {
        buff[idx++] = digits[u % base];
    } while((u /= base) != 0);
 
    for (; idx > 0; idx--)
    {
        console_putchar(buff[idx-1]);
    }
}
 
void
printk(const char *fmt, ...)
{
    va_list args;
    char *ptr;
    int tmp;
 
    va_start(args, fmt);
    for (ptr = (char *)fmt; *ptr != '\0'; ptr++)
    {
        if (*ptr != '%')
        {
            /* TODO: tty/console  */
            console_putchar(*ptr);
            continue;
        }
 
        ptr++;
        switch (*ptr)
        {
            case '%':
                console_putchar('%');
                break;
 
            case 'd':
            case 'i':
                tmp = va_arg(args, int);
                if (tmp < 0)
                {
                    console_putchar('-');
                    printuint(-tmp, 10);
                }
                else
                {
                    printuint(tmp, 10);
                }
                break;
            
            case 'u':
                printuint((va_arg(args, unsigned)), 10);
                break;
 
            case 'x':
                printuint((va_arg(args, unsigned)), 16);
                break;
 
            case 'o':
                console_putchar('0');
                printuint((va_arg(args, unsigned)), 8);
                break;
 
            case 's':
                printstr(va_arg(args, const char *));
                break;
 
            case 'c':
                console_putchar(va_arg(args, int));
                break;
            
            case 'p':
            case 'a':
                printstr("0x");
#ifdef __pdp11__
                printuint((va_arg(args, unsigned)), 16);
#else
                printuint((va_arg(args, uintptr_t)), 16);
#endif
                break;
 
            default:
                console_putchar('%');
                console_putchar(*ptr);
        }
    }
    va_end(args);
    console_flush();
}