Defined EOF as -1 in stdio.h.

Implemented the sprintf() library function in lib/stdio.c which uses the
vsprintf() function.

Implemented a very primative controlling TTY for each process. This is
achieved by a switch in the sys_puts system call which uses the 'ctty'
element of the process' task structure to determine an appropriate I/O
channel. A negative ctty value doesn't equate to any I/O channel
effectively disabling the process' output.

Added the sys_ctty system call which allows a process to set it's own
ctty value.

Removed the sys_rsputs system call. Output to serial is now performed by
the process first setting it's ctty value to 1, then invoking sys_puts.

1 files changed, 3 insertions, 5 deletions

diff --git a/lib/stdio.c b/lib/stdio.c
index a718ee4..67f0a54 100644
--- a/lib/stdio.c
+++ b/lib/stdio.c
@@ -3,7 +3,7 @@
 #include <unistd.h>
 
 _syscall1(int, puts, char*, s);
-_syscall1(int, rsputs, char*, s);
+_syscall1(int, ctty, int, ctty);
 
 int printf(char *fmt, ...) {
   int ret;
@@ -18,15 +18,13 @@ int printf(char *fmt, ...) {
   return ret;
 }
 
-int rsprintf(char *fmt, ...) {
+int sprintf(char *str, char *fmt, ...) {
   int ret;
-  char buf[1024];
   va_list ap;
 
   va_start(ap, fmt);
-  ret = vsprintf(buf, fmt, ap);
+  ret = vsprintf(str, fmt, ap);
   va_end(ap);
 
-  rsputs(buf);
   return ret;
 }