Enable generic earlycon support for nios2. This e.g. allows to use a
8250/16650 UART as earlycon.

In order to get the earlycon, we just need to call parse_early_param()
in early_init_devtree() as soon as the device tree is initially scanned.
By adding an stdout-path property to the dts (done in this patch for
10m50_devboard), the earlycon can be used.

In order to provide early printk support, we need to provide a dummy
implementation of early_console_write(), so that
arch/nios2/kernel/early_printk.c can still be compiled if neither
SERIAL_ALTERA_JTAGUART_CONSOLE nor SERIAL_ALTERA_UART_CONSOLE is
selected. As soon as the altera_uart and altera_jtaguart support
earlycon, the entire file can be removed.

Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Ley Foon Tan <ley.foon.tan@intel.com>

Add .gitignore entries for nios2 specific files generated during the
build process.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Ley Foon Tan <ley.foon.tan@intel.com>

These are the current source files that should not have
executable attributes set.

[ Normally this would be sent through Andrew Morton's tree
  but his quilt tools don't like permission only patches. ]

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The tx-threshold parameter sets the TX FIFO low water threshold
trigger for the Altera 16550-FIFO32 soft IP.

Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Since commit 2aedcd098a94 ('kbuild: suppress annoying "... is up to
date." message'), $(call if_changed,...) is evaluated to "@:"
when there is nothing to do.

We no longer need to add "@:" after $(call if_changed,...) to
suppress "... is up to date." message.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.com>

Max10 is a FPGA device. This patch adds Nios2 support for Max10.
This device tree is based on Max10 hardware reference design.

Signed-off-by: Chee Nouk Phoon <cnphoon@altera.com>
Signed-off-by: Ley Foon Tan <lftan@altera.com>

Signed-off-by: Ley Foon Tan <lftan@altera.com>

This patch adds Makefile and Kconfig files required for building a
nios2 kernel.

Signed-off-by: Ley Foon Tan <lftan@altera.com>

Add device tree support to arch/nios2.

Signed-off-by: Ley Foon Tan <lftan@altera.com>