diff options
Diffstat (limited to 'src/lib/syscalls.c')
-rw-r--r-- | src/lib/syscalls.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/src/lib/syscalls.c b/src/lib/syscalls.c new file mode 100644 index 0000000..6095bd3 --- /dev/null +++ b/src/lib/syscalls.c @@ -0,0 +1,156 @@ +#include <sys/stat.h> +#include "stm32f10x_usart.h" + +/* _end is set in the linker command file */ +extern caddr_t _end; + +/* just in case, most boards have at least some memory */ +#ifndef RAMSIZE +# define RAMSIZE (caddr_t)0x50000 +#endif + +#define STACK_TOP 0x20000800 + +void uart_send(const char*str); + +/* + * sbrk -- changes heap size size. Get nbytes more + * RAM. We just increment a pointer in what's + * left of memory on the board. + */ +caddr_t +_sbrk(nbytes) +int nbytes; +{ + static caddr_t heap_ptr = NULL; + caddr_t base; + + if (heap_ptr == NULL) { + heap_ptr = (caddr_t)&_end; + } + + if ((STACK_TOP - (unsigned int)heap_ptr) >= 0) { + base = heap_ptr; + heap_ptr += nbytes; + return (base); + } else { + uart_send("heap full!\r\n"); + return ((caddr_t)-1); + } +} + +int _open(const char *path, int flags, ...) +{ + return 1; +} + +int _close(int fd) +{ + return 0; +} + +int _fstat(int fd, struct stat *st) +{ + st->st_mode = S_IFCHR; + return 0; +} + +int _isatty(int fd) +{ + return 1; +} + +int isatty(int fd) +{ + return 1; +} + +int _lseek(int fd, off_t pos, int whence) +{ + return -1; +} + +unsigned char getch(void) +{ + while (!(USART2->SR & USART_FLAG_RXNE)); + return USART2->DR; +} + + +int _read(int fd, char *buf, size_t cnt) +{ + *buf = getch(); + + return 1; +} + +void putch(unsigned char c) +{ + if (c == '\n') putch('\r'); + + while (!(USART2->SR & USART_FLAG_TXE)); + USART2->DR = c; +} + +void cgets(char *s, int bufsize) +{ + char *p; + int c; + int i; + + for (i = 0; i < bufsize; i++) { + *(s+i) = 0; + } +// memset(s, 0, bufsize); + + p = s; + + for (p = s; p < s + bufsize-1;) + { + c = getch(); + switch (c) + { + case '\r' : + case '\n' : + putch('\r'); + putch('\n'); + *p = '\n'; + return; + + case '\b' : + if (p > s) + { + *p-- = 0; + putch('\b'); + putch(' '); + putch('\b'); + } + break; + + default : + putch(c); + *p++ = c; + break; + } + } + return; +} + +int _write(int fd, const char *buf, size_t cnt) +{ + int i; +// uart_send("_write\r\n"); + + for (i = 0; i < cnt; i++) + putch(buf[i]); + + return cnt; +} + +/* Override fgets() in newlib with a version that does line editing */ +char *fgets(char *s, int bufsize, void *f) +{ +// uart_send("fgets\r\n"); + cgets(s, bufsize); + return s; +} |