It is useful to be able to record console output and provide console input
via a buffer. This provides sandbox with the ability to run a command and
check its output. If the console is set to silent then no visible output
is generated.

This also provides a means to fix the problem where tests produce unwanted
output, such as errors or warnings. This can be confusing. We can instead
set the console to silent and record this output. It can be checked later
in the test if required.

It is possible that this may prove useful for non-test situations. For
example the console output may be suppressed for normal operations, but
recorded and stored for access by the OS. That feature is not implemented
at present.

Signed-off-by: Simon Glass <sjg@chromium.org>

The console includes a global variable and several functions that are only
used by a small subset of U-Boot files. Before adding more functions, move
the definitions into their own header file.

Signed-off-by: Simon Glass <sjg@chromium.org>

So far the console API uses the following naming convention:

	======Extract======
	typedef struct device_t;

	int	device_register (device_t * dev);
	int	devices_init (void);
	int	device_deregister(char *devname);
	struct list_head* device_get_list(void);
	device_t* device_get_by_name(char* name);
	device_t* device_clone(device_t *dev);
	=======

which is too generic and confusing.

Instead of using device_XX and device_t we change this
into stdio_XX and stdio_dev

This will also allow to add later a generic device mechanism in order
to have support for multiple devices and driver instances.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

Edited commit message.

Signed-off-by: Wolfgang Denk <wd@denx.de>

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>