esp-open-rtos/core/newlib_syscalls.c
Angus Gratton 36886412e6 Add abort() implementation
Also reduces the IRAM footprint of the fatal exception handler, as only
the prelude (which disables interrupts & enables the flash mapping) is
in IRAM now.

Closes #54, relevant to #133.
2016-05-15 22:30:01 +10:00

87 lines
2.5 KiB
C

/* newlib_syscalls.c - newlib syscalls for ESP8266
*
* Part of esp-open-rtos
* Copyright (C) 2105 Superhouse Automation Pty Ltd
* BSD Licensed as described in the file LICENSE
*/
#include <sys/reent.h>
#include <sys/types.h>
#include <sys/errno.h>
#include <espressif/sdk_private.h>
#include <common_macros.h>
#include <esp/uart.h>
#include <stdlib.h>
IRAM caddr_t _sbrk_r (struct _reent *r, int incr)
{
extern char _heap_start; /* linker script defined */
static char * heap_end;
char * prev_heap_end;
if (heap_end == NULL)
heap_end = &_heap_start;
prev_heap_end = heap_end;
/* TODO: Check stack collision
if (heap_end + incr > stack_ptr)
{
_write (1, "_sbrk: Heap collided with stack\n", 32);
abort();
}
*/
heap_end += incr;
return (caddr_t) prev_heap_end;
}
/* syscall implementation for stdio write to UART */
long _write_r(struct _reent *r, int fd, const char *ptr, int len )
{
if(fd != r->_stdout->_file) {
r->_errno = EBADF;
return -1;
}
for(int i = 0; i < len; i++) {
/* Auto convert CR to CRLF, ignore other LFs (compatible with Espressif SDK behaviour) */
if(ptr[i] == '\r')
continue;
if(ptr[i] == '\n')
uart_putc(0, '\r');
uart_putc(0, ptr[i]);
}
return len;
}
/* syscall implementation for stdio read from UART */
__attribute__((weak)) long _read_r( struct _reent *r, int fd, char *ptr, int len )
{
int ch, i;
if(fd != r->_stdin->_file) {
r->_errno = EBADF;
return -1;
}
uart_rxfifo_wait(0, 1);
for(i = 0; i < len; i++) {
ch = uart_getc_nowait(0);
if (ch < 0) break;
ptr[i] = ch;
}
return i;
}
/* Stub syscall implementations follow, to allow compiling newlib functions that
pull these in via various codepaths
*/
__attribute__((alias("syscall_returns_enosys"))) int _open_r(struct _reent *r, const char *pathname, int flags, int mode);
__attribute__((alias("syscall_returns_enosys"))) int _fstat_r(struct _reent *r, int fd, void *buf);
__attribute__((alias("syscall_returns_enosys"))) int _close_r(struct _reent *r, int fd);
__attribute__((alias("syscall_returns_enosys"))) off_t _lseek_r(struct _reent *r, int fd, off_t offset, int whence);
/* Generic stub for any newlib syscall that fails with errno ENOSYS
("Function not implemented") and a return value equivalent to
(int)-1. */
static int syscall_returns_enosys(struct _reent *r)
{
r->_errno=ENOSYS;
return -1;
}