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#include "uart.h"
#include <sys/stat.h>
#include <sys/times.h>
#include <sys/types.h>
#include <errno.h>
#undef errno
extern int errno;
// defined in crt0.S
void _exit(int c);
int _close(int file) { return -1; }
char *__env[1] = {0};
char **environ = __env;
int _execve(char *name, char **argv, char **env) {
errno = ENOMEM;
return -1;
}
int _fork(void) {
errno = EAGAIN;
return -1;
}
int _fstat(int file, struct stat *st) {
st->st_mode = S_IFCHR;
return 0;
}
int _getpid(void) { return 1; }
int _isatty(int file) { return 1; }
int _link(char *old, char *new) {
errno = EMLINK;
return -1;
}
int _lseek(int file, int ptr, int dir) { return 0; }
int _open(const char *name, int flags, int mode) { return -1; }
int _read(int file, char *buf, int len) {
while (!uart_rx_ready())
;
int i;
for (i = 0; i < len; i++) {
if (!uart_rx_ready()) {
break;
}
buf[i] = uart_getc_nonblocking();
}
return i;
}
void *_sbrk(int incr) {
extern void _heap_start;
extern void *_heap_end;
void *prev_heap_end = _heap_end;
void *stack_ptr;
__asm__ volatile("mv %0, sp" : "=r"(stack_ptr));
if (_heap_end + incr > stack_ptr) {
uart_puts("Heap and stack collision\n");
_exit(1);
}
_heap_end += incr;
return prev_heap_end;
}
int _stat(const char *__restrict file, struct stat *__restrict st) {
st->st_mode = S_IFCHR;
return 0;
}
clock_t _times(struct tms *buf) { return (clock_t)-1; }
int _unlink(char *name) {
errno = ENOENT;
return -1;
}
int _wait(int *status) {
errno = ECHILD;
return -1;
}
int _write(int file, char *buf, int len) {
for (int i = 0; i < len; i++) {
uart_putc(buf[i]);
}
return len;
}
int _kill(int pid, int sig) {
errno = EINVAL;
return -1;
}
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