修复I2C读写函数，I2C传输失败时返回成功的问题

[DeviceDriver] fix the dataqueue issues.

Update ethernetif.c

if device->eth_rx is NULL ,rx thread will hard fault...

uart configure shall not been performed if uart is not open.

This reverts commit cd3b0cfff5.

Improve serial DMA rx mode. #628

committed by FH.

patched by FH.

Add MMC/SD change support, which patched by FH.

abort routine will cause sig_xxx() reference.

function `rt_pin_write` is invoked by  function `can_bus_hook`, and it should to be initialized by gpio.c.
but gpio.c was not added in SConscript

fix reset serial receive interrupt flag when close serial

This bug causes buffer overrun.

LWIP_NAT_TMR_INTERVAL_SEC defined in ipv4_nat.h is in miliseconds,
but ip_nat_check_timeout() thinks it's in seconds.

With this bug, all nat entries will expire immediately when
ip_nat_check_timeout() is called.

Note sys_timeout() is in miliseconds.

ref: http://savannah.nongnu.org/bugs/?38219

[DFS] Fix the ramfs issue.

修正components.h中使能RT_USING_DFS_RAMFS宏时，加入ramfs.h头文件

修正finsh不能正确处理"\""和"\x1A"转义;

finsh: change no echo mode. cpp: remove RT_USE_LIBC depends

Signed-off-by: SchumyHao <bob-hjl@126.com>

Signed-off-by: SchumyHao <bob-hjl@126.com>

比如实际目录为abcde，msh执行 cd abc也能执行成功，判断名称时存在bug

For using pthread with IAR tool chain

[DeviceDrivers] Add hardware timer framework

add w25q80 support to spi flash

Fix lpc4088candriver

Sdio

Roughly backport of commit 75534a04327b54f upstream.

Signed-off-by: pangwei <271372443@qq.com>

This reverts commit 326a7d7496.

Add Can Drv

1.Fixed PASV mode issue;
2.Implement RNFR and RNTO command;
3.Change some command code according RFC959;
4.Add command for msh shell;
5.Implement "noop" command.

Update for dfs_lwip and completion.

The problem of finding ethernet interface

To avoid same file name, therefore change the netdb.c to lwip_netdbc in
dfs_lwip.

The old `--keep` parameter for Keil is wrong. RTFM of Keil and get it
right.

Remove dataqueue/pipe if not enable RT_USING_HEAP, supply the missing `not`.

fix: completion wait after, maybe can't clean the flag.

[BSP] Correct pin register name problems

format. It is targeted at 32 bit microcontrollers, but is also fit for
other embedded systems with tight (2-10 kB ROM, <1 kB RAM) memory
constraints.(http://koti.kapsi.fi/jpa/nanopb/)

How to use the example:
	1. move examples/nanopb to bsp/xxxx/
	2. enable macro RT_USING_NANOPB in rtconfig.h
	3. regenerate the project file (scons --target=xxxx)
	4. rebuild the project

[Driver/ringbuffer]: Fix put_force bug

OXape reports: http://www.rt-thread.org/phpBB3/topic3939.html
          driver/ringbuffer: when data length is bigger than space length
          for rb, the read_index in rb is not update.
    When length > space, update the read_index, the bug can be fix, and
          works fine.

If there is no SHT$$INIT_ARRAY, calling
$Super$$__cpp_initialize__aeabi_() will fault. At least until Keil5.12
the problem still exists. So we have to initialize the C++ runtime our
own.

Currently only lpc43xx is supported.

Misc fix

As we are sending C continuously, there is a chance that the
sender(remote) receive an C after sending the first handshake package.
So the sender will interpret it as NAK and re-send the package. So we
just ignore it and proceed.

This saves 1KiB ram usage.

There is no list_mem and only list_memheap when RT_USING_MEMHEAP_AS_HEAP
is enabled.

System will crash when the romfs is erased. Add checks before using them
to avoid it.

sync

Move PNG_NO_WRITE_SUPPORTED outside of RT_USING_NEWLIB. #197

Frequent 'C' on the handshake will confuse some sender(lrzsz for
example).

Make fast path fast and slow path slow.

2. Fix data transfer size calculate error issue;

add some comments of lwip porting

The ptr is set in the following code. So remove the first one.

The digit in octal numbers should with in 0~7. Check on it in
token_proc_number. This issue is found by Clang.

Clang complains about "Null pointer argument in call to string
comparison function". So assert on it.

log_session_lvl is suitable for performance critical places where in
most cases, the log is turned off by level. If the session is const and
the level is greater than session->lvl, the whole function will be
optimized out.

Compiler may do more optimization when the parameter is const.

[USB]fix rt_usbd_set_config() BUG which set the USB device to configurat...

When MSH enabled, the prompt will change at the two shells. So we should
use dynamic prompt when FINSH_USING_MSH defined.

[msh] don't complain on empty command

Just branch out and no complain on command length == 0;

When DFS_USING_WORKDIR is enabled, msh will try to chdir if the command
is not found. For example, if there is folder named "SD", and there is
no `SD` command and `SD.mo` module, typing "SD" in msh will cd to the
folder.

In more detail, the execution order right now is:

1. built-in command
2. module
3. cd to path

If you have a folder named "ps", you have to run `cd ps` to change the
working dir.

Msh can execute module directly. So try to auto-complete the path when
user press TAB. There is a chance that the path is a module.

2.adjust some viable and micro name
3.some other small fix

This reverts commit 5aeedc4f3a, reversing
changes made to 3d80e414ff.

This merge breaks every uart driver in all BSPs. @bright-pan , is there
any way to get this done without breaking existing code?

Add hardware flow support.
Use new struct serial_ringbuffer.

Pass USB CV test verification;
Code cleanup;

This issue causes fstat & lseek not correct.

update CMSIS version to 3.20

fix msh_exec(char* cmd, rt_size_t length) bug

I have to mention that this bug is introduced by myself, in the last
commit <fd07f30f511335f506ae6557e300093d4dde421e> to dfs_nfs.c

fix dfs_unmount bug