add syscalls for iap

iap/syscalls/syscalls.c

@@ -0,0 +1,301 @@
+/*
+ * newlib_stubs.c
+ *
+ *  Created on: 2 Nov 2010
+ *      Author: nanoage.co.uk
+ */
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/times.h>
+#include <sys/unistd.h>
+#include "stm32f4xx_usart.h"
+#include "stm32f4xx.h"
+
+#ifdef SWOTRACE
+/* Set STDIO_USART to 255 as flag that trace output on SWO pin used instead */
+#define STDIO_USART 255
+#else
+/* Set USART number */
+#define STDIO_USART 1 /* Disable UART stdio */
+#endif /* SWOTRACE */
+
+
+#ifndef STDOUT_USART
+#define STDOUT_USART STDIO_USART
+#endif
+
+#ifndef STDERR_USART
+#define STDERR_USART STDIO_USART
+#endif
+
+#ifndef STDIN_USART
+#define STDIN_USART STDIO_USART
+#endif
+
+
+#undef errno
+extern int errno;
+
+/* Variable to receive characters on SWO */
+volatile int32_t ITM_RxBuffer;
+
+/*
+ environ
+ A pointer to a list of environment variables and their values.
+ For a minimal environment, this empty list is adequate:
+ */
+char *__env[1] = { 0 };
+char **environ = __env;
+
+int _write(int file, char *ptr, int len);
+
+void _exit(int status) {
+    _write(1, "exit", 4);
+    while (1) {
+        ;
+    }
+}
+
+int _close(int file) {
+    return -1;
+}
+/*
+ execve
+ Transfer control to a new process. Minimal implementation (for a system without processes):
+ */
+int _execve(char *name, char **argv, char **env) {
+    errno = ENOMEM;
+    return -1;
+}
+/*
+ fork
+ Create a new process. Minimal implementation (for a system without processes):
+ */
+
+int _fork() {
+    errno = EAGAIN;
+    return -1;
+}
+/*
+ fstat
+ Status of an open file. For consistency with other minimal implementations in these examples,
+ all files are regarded as character special devices.
+ The `sys/stat.h' header file required is distributed in the `include' subdirectory for this C library.
+ */
+int _fstat(int file, struct stat *st) {
+    st->st_mode = S_IFCHR;
+    return 0;
+}
+
+/*
+ getpid
+ Process-ID; this is sometimes used to generate strings unlikely to conflict with other processes. Minimal implementation, for a system without processes:
+ */
+
+int _getpid() {
+    return 1;
+}
+
+/*
+ isatty
+ Query whether output stream is a terminal. For consistency with the other minimal implementations,
+ */
+int _isatty(int file) {
+    switch (file){
+    case STDOUT_FILENO:
+    case STDERR_FILENO:
+    case STDIN_FILENO:
+        return 1;
+    default:
+        //errno = ENOTTY;
+        errno = EBADF;
+        return 0;
+    }
+}
+
+
+/*
+ kill
+ Send a signal. Minimal implementation:
+ */
+int _kill(int pid, int sig) {
+    errno = EINVAL;
+    return (-1);
+}
+
+/*
+ link
+ Establish a new name for an existing file. Minimal implementation:
+ */
+
+int _link(char *old, char *new) {
+    errno = EMLINK;
+    return -1;
+}
+
+/*
+ lseek
+ Set position in a file. Minimal implementation:
+ */
+int _lseek(int file, int ptr, int dir) {
+    return 0;
+}
+
+/*
+ sbrk
+ Increase program data space.
+ Malloc and related functions depend on this
+ */
+caddr_t _sbrk(int incr) {
+
+    extern char _ebss; // Defined by the linker
+    extern char __bss_end__;
+    static char *heap_end;
+    char *prev_heap_end;
+
+    if (heap_end == 0) {
+    	//heap_end = &_ebss;
+    	heap_end = &__bss_end__;
+    }
+    prev_heap_end = heap_end;
+
+char * stack = (char*) __get_MSP();
+     if (heap_end + incr >  stack)
+     {
+         _write (STDERR_FILENO, "Heap and stack collision\n", 25);
+         errno = ENOMEM;
+         return  (caddr_t) -1;
+         //abort ();
+     }
+
+    heap_end += incr;
+    return (caddr_t) prev_heap_end;
+
+}
+
+/*
+ read
+ Read a character to a file. `libc' subroutines will use this system routine for input from all files, including stdin
+ Returns -1 on error or blocks until the number of characters have been read.
+ */
+
+
+int _read(int file, char *ptr, int len) {
+    int n;
+    int num = 0;
+    switch (file) {
+    case STDIN_FILENO:
+        for (n = 0; n < len; n++) {
+#if   STDIN_USART == 1
+            while ((USART1->SR & USART_FLAG_RXNE) == (uint16_t)RESET) {}
+            char c = (char)(USART1->DR & (uint16_t)0x01FF);
+#elif STDIN_USART == 2
+            while ((USART2->SR & USART_FLAG_RXNE) == (uint16_t) RESET) {}
+            char c = (char) (USART2->DR & (uint16_t) 0x01FF);
+#elif STDIN_USART == 3
+            while ((USART3->SR & USART_FLAG_RXNE) == (uint16_t)RESET) {}
+            char c = (char)(USART3->DR & (uint16_t)0x01FF);
+#elif STDIN_USART == 255
+            /* TODO Test this feature */
+            char c = (char)ITM_ReceiveChar();
+#elif STDIN_USART == 0
+            /* Return NULL */
+            char c = '\0';
+#endif
+            *ptr++ = c;
+            num++;
+        }
+        break;
+    default:
+        errno = EBADF;
+        return -1;
+    }
+    return num;
+}
+
+/*
+ stat
+ Status of a file (by name). Minimal implementation:
+ int    _EXFUN(stat,( const char *__path, struct stat *__sbuf ));
+ */
+
+int _stat(const char *filepath, struct stat *st) {
+    st->st_mode = S_IFCHR;
+    return 0;
+}
+
+/*
+ times
+ Timing information for current process. Minimal implementation:
+ */
+
+clock_t _times(struct tms *buf) {
+    return -1;
+}
+
+/*
+ unlink
+ Remove a file's directory entry. Minimal implementation:
+ */
+int _unlink(char *name) {
+    errno = ENOENT;
+    return -1;
+}
+
+/*
+ wait
+ Wait for a child process. Minimal implementation:
+ */
+int _wait(int *status) {
+    errno = ECHILD;
+    return -1;
+}
+
+/*
+ write
+ Write a character to a file. `libc' subroutines will use this system routine for output to all files, including stdout
+ Returns -1 on error or number of bytes sent
+ */
+int _write(int file, char *ptr, int len) {
+    int n;
+    switch (file) {
+    case STDOUT_FILENO: /*stdout*/
+        for (n = 0; n < len; n++) {
+#if STDOUT_USART == 1
+            while ((USART1->SR & USART_FLAG_TC) == (uint16_t)RESET) {}
+            USART1->DR = (*ptr++ & (uint16_t)0x01FF);
+#elif  STDOUT_USART == 2
+            while ((USART2->SR & USART_FLAG_TC) == (uint16_t) RESET) {
+            }
+            USART2->DR = (*ptr++ & (uint16_t) 0x01FF);
+#elif  STDOUT_USART == 3
+            while ((USART3->SR & USART_FLAG_TC) == (uint16_t)RESET) {}
+            USART3->DR = (*ptr++ & (uint16_t)0x01FF);
+#elif STDOUT_USART == 255
+            ITM_SendChar(*ptr++ & (uint16_t)0x00FF);
+#endif
+        }
+        break;
+    case STDERR_FILENO: /* stderr */
+        for (n = 0; n < len; n++) {
+#if STDERR_USART == 1
+            while ((USART1->SR & USART_FLAG_TC) == (uint16_t)RESET) {}
+            USART1->DR = (*ptr++ & (uint16_t)0x01FF);
+#elif  STDERR_USART == 2
+            while ((USART2->SR & USART_FLAG_TC) == (uint16_t) RESET) {
+            }
+            USART2->DR = (*ptr++ & (uint16_t) 0x01FF);
+#elif  STDERR_USART == 3
+            while ((USART3->SR & USART_FLAG_TC) == (uint16_t)RESET) {}
+            USART3->DR = (*ptr++ & (uint16_t)0x01FF);
+#elif STDERR_USART == 255
+            ITM_SendChar(*ptr++ & (uint16_t)0x00FF);
+#endif
+        }
+        break;
+    default:
+        errno = EBADF;
+        return -1;
+    }
+    return len;
+}