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/*
* Copyright (c) 2017 Richard Braun.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include "cpu.h"
#include "thread.h"
#include "uart.h"
#define PRINTF_BUFFER_SIZE 1024
/*
* This implementation uses a global buffer in order to avoid allocating
* from the stack, since stacks may be very small.
*/
static char printf_buffer[PRINTF_BUFFER_SIZE];
void
putchar(unsigned char c)
{
uart_write(c);
}
int
getchar(void)
{
uint8_t byte;
int error;
error = uart_read(&byte);
return error ? EOF : byte;
}
int
printf(const char *format, ...)
{
va_list ap;
int length;
va_start(ap, format);
length = vprintf(format, ap);
va_end(ap);
return length;
}
int
vprintf(const char *format, va_list ap)
{
uint32_t eflags;
int length;
thread_preempt_disable();
eflags = cpu_intr_save();
length = vsnprintf(printf_buffer, sizeof(printf_buffer), format, ap);
for (const char *ptr = printf_buffer; *ptr != '\0'; ptr++) {
uart_write((uint8_t)*ptr);
}
cpu_intr_restore(eflags);
thread_preempt_enable();
return length;
}
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