1. Add macro check in rtdebug.h;
2. Use RT_USING_POSIX for poll/select, stdin etc.
3. Split dfs_posix.h to dfs_posix.h, dfs_poll.h and dfs_select.h;

1. Add signal implementation;
2. Change the 'rt_uint8_t' of cmd to 'int';

This is a simple work around to the current device stack design. A
ref_count could let different modules to open/close the same device
independently without interfere others in some degree.

But there is still some data shared between the modules, like flag,
open_flag and user_data. Moreover, it won't yield an error if A open a
device, and B read from it before open it in B. Maybe alloc a new handle
in rt_device_open will be the ultimate solution. But that is much bigger
change and we may leave it to future development.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2519 bbd45198-f89e-11dd-88c7-29a3b14d5316

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2502 bbd45198-f89e-11dd-88c7-29a3b14d5316

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2386 bbd45198-f89e-11dd-88c7-29a3b14d5316

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2355 bbd45198-f89e-11dd-88c7-29a3b14d5316

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2205 bbd45198-f89e-11dd-88c7-29a3b14d5316

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2005 bbd45198-f89e-11dd-88c7-29a3b14d5316

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1998 bbd45198-f89e-11dd-88c7-29a3b14d5316

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1885 bbd45198-f89e-11dd-88c7-29a3b14d5316

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1882 bbd45198-f89e-11dd-88c7-29a3b14d5316

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1715 bbd45198-f89e-11dd-88c7-29a3b14d5316

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1132 bbd45198-f89e-11dd-88c7-29a3b14d5316

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@690 bbd45198-f89e-11dd-88c7-29a3b14d5316

remove rt_passed_second in clock; init device driver when driver has been opened if it is not in activate status; change interrupt nest count to rt_uint8_t; add rt_console_set_device function in kservice.c (rt_kprintf function can use device right now)

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@464 bbd45198-f89e-11dd-88c7-29a3b14d5316

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@226 bbd45198-f89e-11dd-88c7-29a3b14d5316

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@198 bbd45198-f89e-11dd-88c7-29a3b14d5316

fix the cortex-m3 context switch bug when interrupt preempts pendsv exception; add RT_LWIP_ETH_PAD_SIZE option; fix device activate flag set issue in init function.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@193 bbd45198-f89e-11dd-88c7-29a3b14d5316

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2 bbd45198-f89e-11dd-88c7-29a3b14d5316