128 lines
3.4 KiB
C
128 lines
3.4 KiB
C
#include <stdarg.h>
|
|
#include <limits.h>
|
|
#include "std/kstd.h"
|
|
#include "std/std.h"
|
|
#include "gfx/terminal.h"
|
|
|
|
int kputchar(int ic) {
|
|
char c = (char) ic;
|
|
terminal_write(&c, sizeof(c));
|
|
return ic;
|
|
}
|
|
|
|
static bool print(const char* data, size_t length) {
|
|
const unsigned char* bytes = (const unsigned char*) data;
|
|
for (size_t i = 0; i < length; i++) {
|
|
if (kputchar(bytes[i]) == (-1)) { // EOF??
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// https://wiki.osdev.org/Meaty_Skeleton
|
|
int kprintf(const char* restrict format, ...) {
|
|
va_list parameters;
|
|
va_start(parameters, format);
|
|
|
|
int written = 0;
|
|
|
|
while (*format != '\0') {
|
|
size_t maxrem = INT_MAX - written;
|
|
|
|
if (format[0] != '%' || format[1] == '%') {
|
|
if (format[0] == '%')
|
|
format++;
|
|
size_t amount = 1;
|
|
while (format[amount] && format[amount] != '%')
|
|
amount++;
|
|
if (maxrem < amount) {
|
|
// TODO: Set errno to EOVERFLOW.
|
|
return -1;
|
|
}
|
|
if (!print(format, amount))
|
|
return -1;
|
|
format += amount;
|
|
written += amount;
|
|
continue;
|
|
}
|
|
|
|
const char* format_begun_at = format++;
|
|
|
|
if (*format == 'c') {
|
|
format++;
|
|
char c = (char) va_arg(parameters, int /* char promotes to int */);
|
|
if (!maxrem) {
|
|
// TODO: Set errno to EOVERFLOW.
|
|
return -1;
|
|
}
|
|
if (!print(&c, sizeof(c)))
|
|
return -1;
|
|
written++;
|
|
} else if (*format == 's') {
|
|
format++;
|
|
const char* str = va_arg(parameters, const char*);
|
|
size_t len = strlen(str);
|
|
if (maxrem < len) {
|
|
// TODO: Set errno to EOVERFLOW.
|
|
return -1;
|
|
}
|
|
if (!print(str, len))
|
|
return -1;
|
|
written += len;
|
|
} else if (*format == 'd') {
|
|
format++;
|
|
int val = va_arg(parameters, int);
|
|
int base = 10;
|
|
char *str;
|
|
|
|
// note: flawed implementation
|
|
// based on: https://www.strudel.org.uk/itoa/
|
|
if (val == 0) {
|
|
str = "0\0";
|
|
} else {
|
|
static char buf[32] = {0};
|
|
int i = 30;
|
|
for(; val && i ; --i, val /= base) {
|
|
buf[i] = "0123456789abcdef"[val % base];
|
|
}
|
|
str = &buf[i+1];
|
|
}
|
|
|
|
size_t len = strlen(str);
|
|
if (maxrem < len) {
|
|
// TODO: Set errno to EOVERFLOW.
|
|
return -1;
|
|
}
|
|
print(str, len);
|
|
written += len;
|
|
} else {
|
|
format = format_begun_at;
|
|
size_t len = strlen(format);
|
|
if (maxrem < len) {
|
|
// TODO: Set errno to EOVERFLOW.
|
|
return -1;
|
|
}
|
|
if (!print(format, len))
|
|
return -1;
|
|
written += len;
|
|
format += len;
|
|
}
|
|
}
|
|
|
|
va_end(parameters);
|
|
return written;
|
|
}
|
|
|
|
void kputs(const char* data) {
|
|
kprintf("%s\n", data);
|
|
}
|
|
|
|
__attribute__((__noreturn__))
|
|
void kabort(void) {
|
|
kprintf("kabort(): halting kernel...\n");
|
|
asm volatile("cli");
|
|
asm volatile("hlt");
|
|
while (1) {}
|
|
__builtin_unreachable();
|
|
}
|