fef/ardix
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

stdio: refactor printk to printf and friends

Browse source
This commit is contained in:
anna 2021-08-01 18:53:22 +02:00
parent 474974b779
commit 4db1702078
Signed by: fef
GPG key ID: EC22E476DC2D3D84
10 changed files with 354 additions and 246 deletions

4
arch/at91sam3x8e/startup.c
View file

@ -25,7 +25,7 @@ extern uint32_t _sheap; /* heap start */
extern uint32_t _eheap; /* heap end */
/* implementation in init/main.c */
void main(void);
extern int main(void);
__naked void irq_reset(void)
{
@ -38,7 +38,7 @@ __naked void irq_reset(void)
malloc_init(&_sheap, (size_t)(&_eheap) - (size_t)(&_sheap));
/* start the Kernel */
do_bootstrap();
main();
/* halt (this should never be reached) */
while (1);

25
include/ardix/printk.h
View file

@ -1,25 +0,0 @@
/* See the end of this file for copyright, license, and warranty information. */
#pragma once
/**
* Print to the kernel log buffer.
*
* @param fmt: A printf-style format string.
* @return The amount of bytes written, or a negative POSIX number
*/
__attribute__(( format(printf, 1, 2) ))
int printk(const char *fmt, ...);
/*
* This file is part of Ardix.
* Copyright (c) 2020, 2021 Felix Kopp <owo@fef.moe>.
*
* Ardix is non-violent software: you may only use, redistribute,
* and/or modify it under the terms of the CNPLv6+ as found in
* the LICENSE file in the source code root directory or at
* <https://git.pixie.town/thufie/CNPL>.
*
* Ardix comes with ABSOLUTELY NO WARRANTY, to the extent
* permitted by applicable law. See the CNPLv6+ for details.
*/

1
include/config.h.in
View file

@ -22,6 +22,7 @@
#define CONFIG_SCHED_MAXPROC @CONFIG_SCHED_MAXPROC@
#define CONFIG_SERIAL_BAUD @CONFIG_SERIAL_BAUD@
#define CONFIG_SERIAL_BUFSZ @CONFIG_SERIAL_BUFSZ@
#define CONFIG_PRINTF_BUFSZ @CONFIG_PRINTF_BUFSZ@
/*
* This file is part of Ardix.

44
include/stdio.h Normal file
View file

@ -0,0 +1,44 @@
/* See the end of this file for copyright, license, and warranty information. */
#pragma once
#include <stdarg.h>
#include <toolchain.h>
/*
* We sacrifice performance for less memory usage by not having a userland
* structure for `FILE`. Instead, we cast the file descriptor to a pointer and
* use that for syscalls.
*/
struct _user_file { void *_undefined; };
#define FILE struct _user_file
#define _file_to_fd(f) ((int)( (intptr_t)(f) ))
#define _fd_to_file(fd) ((FILE *)( (intptr_t)(fd) ))
#define stdin _fd_to_file(0)
#define stdout _fd_to_file(1)
#define stderr _fd_to_file(2)
__shared int printf(const char *restrict fmt, ...)
__attribute__(( format(printf, 1, 2) ));
__shared int vprintf(const char *restrict fmt, va_list args);
__shared int fprintf(FILE *f, const char *restrict fmt, ...)
__attribute__(( format(printf, 2, 3) ));
__shared int vfprintf(FILE *f, const char *restrict fmt, va_list args);
/*
* This file is part of Ardix.
* Copyright (c) 2020, 2021 Felix Kopp <owo@fef.moe>.
*
* Ardix is non-violent software: you may only use, redistribute,
* and/or modify it under the terms of the CNPLv6+ as found in
* the LICENSE file in the source code root directory or at
* <https://git.pixie.town/thufie/CNPL>.
*
* Ardix comes with ABSOLUTELY NO WARRANTY, to the extent
* permitted by applicable law. See the CNPLv6+ for details.
*/

22
init/main.c
View file

@ -4,12 +4,12 @@
#include <ardix/io.h>
#include <ardix/kent.h>
#include <ardix/printk.h>
#include <ardix/sched.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <unistd.h>
#define REG_PIOB_PER (*(uint32_t *)0x400E1000U)
@ -25,7 +25,7 @@
* This is invoked from the startup code (usually) located in
* arch/<architecture>/startup.c.
*/
void main(void)
int main(void)
{
uint32_t count = 0;
unsigned int print_count = 0;
@ -34,19 +34,27 @@ void main(void)
REG_PIOB_PER = 1 << 27;
REG_PIOB_CODR = 1 << 27;
kent_root_init();
int err = kent_root_init();
if (err != 0)
return err;
sched_init();
err = sched_init();
if (err != 0)
return err;
devices_init();
err = devices_init();
if (err != 0)
return err;
io_init();
err = io_init();
if (err != 0)
return err;
while (true) {
if (count++ != 1000000)
continue;
printk("hello, world (%u)!\n", print_count);
printf("hello, world (%u)!\n", print_count);
print_count++;
if (print_count % 2)

1
kernel/CMakeLists.txt
View file

@ -13,7 +13,6 @@ target_sources(ardix_kernel PRIVATE
dma.c
io.c
kent.c
printk.c
ringbuf.c
sched.c
serial.c

211
kernel/printk.c
View file

@ -1,211 +0,0 @@
/* See the end of this file for copyright, license, and warranty information. */
#include <arch/serial.h>
#include <ardix/dma.h>
#include <ardix/printk.h>
#include <ardix/ringbuf.h>
#include <ardix/serial.h>
#include <errno.h>
/* Using GCC's stdarg.h is recommended even with -nodefaultlibs and -fno-builtin */
#include <stdarg.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <toolchain.h>
#ifndef CONFIG_PRINTK_BUFSZ
#define CONFIG_PRINTK_BUFSZ 64
#endif
/*
* TODO: THIS CAUSES A STACK BUFFER OVERFLOW ON SYSTEMS WHERE INT IS 64 BITS
*/
/* 10 decimal digits of 4294967295 (2 ** 32 - 1) */
#define PRINTK_UINT_BUFSZ 10
static ssize_t printk_flush(struct ringbuf *buf)
{
ssize_t ret;
struct dmabuf *dma = dmabuf_create(&serial_default_device->device, buf->len);
if (dma == NULL)
return -ENOMEM;
ringbuf_read(dma->data, buf, buf->len);
ret = serial_write_dma(serial_default_device, dma);
dmabuf_put(dma);
return ret;
}
__rodata static const char fmt_hex_table[] = {
'0', '1', '2', '3',
'4', '5', '6', '7',
'8', '9', 'a', 'b',
'c', 'd', 'e', 'f',
};
static int fmt_handle_ptr(struct ringbuf *buf, uintptr_t ptr)
{
int ret;
/* 2 chars per byte, plus 2 for the "0x" hex prefix */
char str[2 * sizeof(uintptr_t) + 2];
char *pos = &str[2 * sizeof(uintptr_t) + 1];
str[0] = '0';
str[1] = 'x';
do {
*pos-- = fmt_hex_table[ptr & 0xf];
ptr >>= 4;
} while (pos != &str[2]);
ret = ringbuf_write(buf, &str[0], 2 * sizeof(uintptr_t) + 2);
return ret;
}
static int fmt_handle_uint(struct ringbuf *buf, unsigned int u)
{
int ret;
char str[PRINTK_UINT_BUFSZ];
char *pos = &str[PRINTK_UINT_BUFSZ - 1];
do {
/* stupid big endian humans, forcing us to do the whole thing in reverse */
*pos-- = (char)(u % 10) + '0'; /* convert to ASCII */
u /= 10;
} while (u != 0);
pos++;
ret = ringbuf_write(buf, pos, PRINTK_UINT_BUFSZ - (pos - &str[0]));
return ret;
}
static inline int fmt_handle_int(struct ringbuf *buf, int i)
{
int ret = 0;
char minus = '-';
if (i < 0) {
ret = ringbuf_write(buf, &minus, sizeof(minus));
i = -i;
}
ret += fmt_handle_uint(buf, i);
return ret;
}
/**
* Parse a formatting escape sequence, fetch the parameter from the `va_arg`
* stack, and print the resulting string to the standard serial console.
*
* @param pos: A reference to the pointer to the fmt sequence beginner (`%`).
* This is updated to point to the first character *after* the entire
* escape sequence.
* @param args: A pointer to the varargs list. Will be manipulated.
* @returns The amount of bytes written, or a negative POSIX error code.
*/
static inline int fmt_handle(struct ringbuf *buf, const char **pos, va_list args)
{
int ret = 0;
union {
int c;
int d;
uintptr_t p;
char *s;
unsigned int u;
} val;
switch (**pos) {
case '%': /* literal percent sign */
ret = ringbuf_write(buf, *pos, sizeof(**pos));
break;
case 'c': /* char */
val.c = va_arg(args, typeof(val.c));
ret = ringbuf_write(buf, &val.c, sizeof(val.c));
break;
case 'd': /* int */
val.d = va_arg(args, typeof(val.d));
ret = fmt_handle_int(buf, val.d);
break;
case 'p': /* ptr */
val.p = va_arg(args, typeof(val.p));
ret = fmt_handle_ptr(buf, val.p);
break;
case 's': /* string */
val.s = va_arg(args, typeof(val.s));
ret = (int)strlen(val.s);
ret = ringbuf_write(buf, val.s, (size_t)ret);
break;
case 'u': /* unsigned int */
val.u = va_arg(args, typeof(val.u));
ret = fmt_handle_uint(buf, val.u);
break;
}
(*pos)++;
return ret;
}
int printk(const char *fmt, ...)
{
va_list args;
int ret = 0;
int tmpret;
const char *tmp = fmt;
struct ringbuf *buf = ringbuf_create(CONFIG_PRINTK_BUFSZ);
if (buf == NULL)
return -ENOMEM;
va_start(args, fmt);
while (*tmp != '\0') {
if (*tmp++ == '%') {
/* flush out everything we have so far (minus one char for %) */
ret += (int)ringbuf_write(buf, fmt, (size_t)tmp - (size_t)fmt - 1);
tmpret = fmt_handle(buf, &tmp, args);
/*
* act as if the current position were the beginning in
* order to make the first step of this if block easier
*/
fmt = tmp;
if (tmpret < 0)
break;
ret += tmpret;
}
}
if (tmp != fmt && ret >= 0)
ret += ringbuf_write(buf, fmt, (size_t)tmp - (size_t)fmt);
va_end(args);
printk_flush(buf);
ringbuf_destroy(buf);
return ret;
}
/*
* This file is part of Ardix.
* Copyright (c) 2020, 2021 Felix Kopp <owo@fef.moe>.
*
* Ardix is non-violent software: you may only use, redistribute,
* and/or modify it under the terms of the CNPLv6+ as found in
* the LICENSE file in the source code root directory or at
* <https://git.pixie.town/thufie/CNPL>.
*
* Ardix comes with ABSOLUTELY NO WARRANTY, to the extent
* permitted by applicable law. See the CNPLv6+ for details.
*/

1
lib/CMakeLists.txt
View file

@ -11,6 +11,7 @@ target_sources(ardix_lib PRIVATE
errno.c
list.c
malloc.c
printf.c
string.c
unistd.c
)

289
lib/printf.c Normal file
View file

@ -0,0 +1,289 @@
/* See the end of this file for copyright, license, and warranty information. */
#include <ardix/malloc.h>
#include <errno.h>
/* Using GCC's stdarg.h is recommended even with -nodefaultlibs and -fno-builtin */
#include <stdarg.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <config.h>
#include <toolchain.h>
#if __SIZEOF_INT__ == 2
/* 5 decimal digits of 65535 (2 ** 16 - 1) */
# define PRINTF_UINT_BUFSZ 5
#elif __SIZEOF_INT__ == 4
/* 10 decimal digits of 4294967295 (2 ** 32 - 1) */
# define PRINTF_UINT_BUFSZ 10
#else
/* 20 decimal digits of 18446744073709551616 (2 ** 64 - 1) */
# define PRINTF_UINT_BUFSZ 20
#endif
struct printf_buf {
size_t len;
int fd;
uint8_t data[0];
};
static struct printf_buf *printf_buf_create(int fd)
{
struct printf_buf *buf = malloc(sizeof(*buf) + CONFIG_PRINTF_BUFSZ);
if (buf != NULL) {
buf->len = 0;
buf->fd = fd;
}
return buf;
}
static void printf_buf_destroy(struct printf_buf *buf)
{
if (buf->len != 0)
write(buf->fd, &buf->data[0], buf->len);
free(buf);
}
static ssize_t printf_buf_write(struct printf_buf *buf, const void *data, size_t len)
{
ssize_t ret = 0;
const uint8_t *tmp = data;
while (ret != (ssize_t)len) {
if (buf->len == CONFIG_PRINTF_BUFSZ) {
/*
* TODO: We don't need to take the syscall detour
* if we are already in kernel context
*/
ssize_t write_ret = write(buf->fd, &buf->data[0], buf->len);
if (write_ret < 0) {
ret = write_ret;
break;
}
if (write_ret == 0) {
/*
* assume something has failed spectacularly
* if write() didn't even write a single byte
*/
ret = -EIO;
break;
}
if (write_ret != (ssize_t)buf->len)
memmove(&buf->data[0], &buf->data[write_ret], buf->len - write_ret);
buf->len -= write_ret;
}
buf->data[buf->len++] = *tmp++;
ret++;
}
return ret;
}
static int fmt_handle_ptr(struct printf_buf *buf, uintptr_t ptr)
{
static const char fmt_hex_table[] = {
'0', '1', '2', '3',
'4', '5', '6', '7',
'8', '9', 'a', 'b',
'c', 'd', 'e', 'f',
};
int ret;
/* 2 chars per byte, plus 2 for the "0x" hex prefix */
char str[2 * sizeof(uintptr_t) + 2];
char *pos = &str[2 * sizeof(uintptr_t) + 1];
str[0] = '0';
str[1] = 'x';
do {
*pos-- = fmt_hex_table[ptr & 0xf];
ptr >>= 4;
} while (pos != &str[2]);
ret = printf_buf_write(buf, &str[0], 2 * sizeof(uintptr_t) + 2);
return ret;
}
static int fmt_handle_uint(struct printf_buf *buf, unsigned int u)
{
int ret;
char str[PRINTF_UINT_BUFSZ];
char *pos = &str[PRINTF_UINT_BUFSZ - 1];
do {
/* stupid big endian humans, forcing us to do the whole thing in reverse */
*pos-- = (char)(u % 10) + '0'; /* convert to ASCII */
u /= 10;
} while (u != 0);
pos++;
ret = printf_buf_write(buf, pos, PRINTF_UINT_BUFSZ - (pos - &str[0]));
return ret;
}
static inline int fmt_handle_int(struct printf_buf *buf, int i)
{
int ret = 0;
char minus = '-';
if (i < 0) {
ret = printf_buf_write(buf, &minus, sizeof(minus));
i = -i;
}
ret += fmt_handle_uint(buf, i);
return ret;
}
/**
* Parse a formatting escape sequence, fetch the parameter from the `va_arg`
* stack, and print the resulting string to the standard serial console.
*
* @param pos: A reference to the pointer to the fmt sequence beginner (`%`).
* This is updated to point to the first character *after* the entire
* escape sequence.
* @param args: A pointer to the varargs list. Will be manipulated.
* @returns The amount of bytes written, or a negative POSIX error code.
*/
static inline int fmt_handle(struct printf_buf *buf, const char **pos, va_list args)
{
int ret = 0;
union {
int c;
int d;
uintptr_t p;
char *s;
unsigned int u;
} val;
switch (**pos) {
case '%': /* literal percent sign */
ret = printf_buf_write(buf, *pos, sizeof(**pos));
break;
case 'c': /* char */
val.c = va_arg(args, typeof(val.c));
ret = printf_buf_write(buf, &val.c, sizeof(val.c));
break;
case 'd': /* int */
val.d = va_arg(args, typeof(val.d));
ret = fmt_handle_int(buf, val.d);
break;
case 'p': /* ptr */
val.p = va_arg(args, typeof(val.p));
ret = fmt_handle_ptr(buf, val.p);
break;
case 's': /* string */
val.s = va_arg(args, typeof(val.s));
ret = (int)strlen(val.s);
ret = printf_buf_write(buf, val.s, (size_t)ret);
break;
case 'u': /* unsigned int */
val.u = va_arg(args, typeof(val.u));
ret = fmt_handle_uint(buf, val.u);
break;
}
(*pos)++;
return ret;
}
int vfprintf(FILE *f, const char *fmt, va_list args)
{
ssize_t ret = 0;
const char *tmp = fmt;
struct printf_buf *buf = printf_buf_create(_file_to_fd(f));
if (buf == NULL)
return -ENOMEM;
while (*tmp != '\0') {
if (*tmp++ == '%') {
/* flush out everything we have so far (minus one char for %) */
ssize_t tmpret = printf_buf_write(buf, fmt, (size_t)tmp - (size_t)fmt - 1);
if (tmpret < 0) {
ret = tmpret;
break;
}
ret += tmpret;
tmpret = fmt_handle(buf, &tmp, args);
/*
* act as if the current position were the beginning in
* order to make the first step of this if block easier
*/
fmt = tmp;
if (tmpret < 0)
break;
ret += tmpret;
}
}
if (tmp != fmt && ret >= 0)
ret += printf_buf_write(buf, fmt, (size_t)tmp - (size_t)fmt);
printf_buf_destroy(buf);
return (int)ret;
}
int vprintf(const char *fmt, va_list args)
{
return vfprintf(stdout, fmt, args);
}
int fprintf(FILE *f, const char *fmt, ...)
{
int ret;
va_list args;
va_start(args, fmt);
ret = vfprintf(f, fmt, args);
va_end(args);
return ret;
}
int printf(const char *fmt, ...)
{
int ret;
va_list args;
va_start(args, fmt);
ret = vfprintf(stdout, fmt, args);
va_end(args);
return ret;
}
/*
* This file is part of Ardix.
* Copyright (c) 2020, 2021 Felix Kopp <owo@fef.moe>.
*
* Ardix is non-violent software: you may only use, redistribute,
* and/or modify it under the terms of the CNPLv6+ as found in
* the LICENSE file in the source code root directory or at
* <https://git.pixie.town/thufie/CNPL>.
*
* Ardix comes with ABSOLUTELY NO WARRANTY, to the extent
* permitted by applicable law. See the CNPLv6+ for details.
*/

2
options.cmake
View file

@ -19,6 +19,8 @@ set_property(CACHE CONFIG_SERIAL_BAUD PROPERTY STRINGS
set(CONFIG_SERIAL_BUFSZ 256 CACHE STRING "Default serial buffer size in bytes")
set(CONFIG_PRINTF_BUFSZ 64 CACHE STRING "Default buffer size for printf() and friends")
# This file is part of Ardix.
# Copyright (c) 2021 Felix Kopp <owo@fef.moe>.
#