treewide: remove references to CREDITS ...

The CREDITS file was removed from barebox in 2015 by commit 6570288f2d97
("Remove the CREDITS file"). Remove references to it from several files.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

serial: efi-stdio: Add simple_text_input_ex_protocol backend ...

EFI implementations differ in how simple_text_input_protocol treats
ctrl+alpha combinations. OVMF (used with QEMU) returns a Unicode control
character, the UEFI on the Dell Latitude 7490 on the other hand ignores
the ctrl completely and returns just the letter rendering utilities
like barebox edit unusable.

To fix this, the simple_text_input_ex_protocol can be leveraged as it
additionally provides the state of modifier keys. Extend efi-stdio to use
it where possible.

Cc: Michael Olbrich <mol@pengutronix.de>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

serial: efi-stdio: replace globals with handles in priv struct ...

Despite assigning efi_sys_table->{con_in,con_out} to priv->{in,out},
some functions still use the global efi_sys_table->{con_in,con_out}.
Let's restrict globals access to the probe function and have the priv
struct completely describe input and output used in the callbacks.
No functional change.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

console: fix out-of-bounds read in dputc(/dev/*, ...) ...

Trying to output a single character via
	echo -a /dev/serial0-1
currently results in garbage output after the newline, because console.c's
fops_write discards the buffer length and passes the buffer to
(struct cdev)::puts which only handles NUL-terminated strings.

Fix this by amending (struct cdev)::puts with a new nbytes parameter,
which is correctly propagated. All this functions now return at most the
nbytes parameter they were passed in. This fixes __console_puts, which
used to count new lines twice in its return value.

Fixes: b4f55fcf35 ("console: expose consoles in devfs")
Cc: Bastian Krause <bst@pengutronix.de>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

efi: move bus driver to driver/efi ...

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

serial: efi: improve input handling ...

0x08 is the scan-code for 'backspace' not 'delete'.
0x17 indicates the start of an escape sequence, such as "[3~" for
'delete'.

Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

serial: Add EFI stdio driver ...

This adds a driver which uses the EFI stdin/stdout interfaces to
implement a barebox console. Keyboard input should be fairly complete,
but not all vt100 needed by barebox work properly. The clear-to-eol
escape is missing causing garbled output in the editor.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>