[libc] Update libc.

1. Add POSIX termios implementation;
2. Add POSIX signals implementation;
3. Add stdio for each libc.

2 files changed, 27 insertions, 0 deletions

diff --git a/components/libc/timer/SConscript b/components/libc/timer/SConscript
new file mode 100644
index 0000000000..a01700aa8d
--- /dev/null
+++ b/components/libc/timer/SConscript
@@ -0,0 +1,12 @@
+# RT-Thread building script for component
+
+from building import *
+
+cwd = GetCurrentDir()
+src = Glob('*.c') + Glob('*.cpp')
+CPPPATH = [cwd]
+
+group = DefineGroup('libc', src, 
+    depend = ['RT_USING_LIBC', 'RT_USING_POSIX_TIMER'], CPPPATH = CPPPATH)
+
+Return('group')
diff --git a/components/libc/timer/posix_sleep.c b/components/libc/timer/posix_sleep.c
new file mode 100644
index 0000000000..b4b33722ac
--- /dev/null
+++ b/components/libc/timer/posix_sleep.c
@@ -0,0 +1,15 @@
+#include <stdlib.h>
+#include <rtthread.h>
+
+#include <unistd.h>
+
+unsigned int sleep(unsigned int seconds)
+{
+    rt_tick_t delta_tick;
+
+    delta_tick = rt_tick_get();
+    rt_thread_delay(seconds * RT_TICK_PER_SECOND);
+    delta_tick = rt_tick_get() - delta_tick;
+
+    return seconds - delta_tick/RT_TICK_PER_SECOND;
+}