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| author | Tobias Klauser <tklauser@distanz.ch> | 2017-04-03 05:09:04 +0200 |
|---|---|---|
| committer | Ley Foon Tan <ley.foon.tan@intel.com> | 2017-05-08 10:59:19 +0200 |
| commit | 44a4ed42576da5f3387005a1667cb3e7aedfd687 (patch) | |
| tree | d1963ca7e55fc9a21178bd42e30de1a11f3a5b28 /arch/nios2 | |
| parent | nios2: constify irq_domain_ops (diff) | |
| download | linux-44a4ed42576da5f3387005a1667cb3e7aedfd687.tar.xz linux-44a4ed42576da5f3387005a1667cb3e7aedfd687.zip | |
nios2: enable earlycon support
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>
Diffstat (limited to 'arch/nios2')
| -rw-r--r-- | arch/nios2/Kconfig.debug | 1 | ||||
| -rw-r--r-- | arch/nios2/boot/dts/10m50_devboard.dts | 3 | ||||
| -rw-r--r-- | arch/nios2/kernel/early_printk.c | 7 | ||||
| -rw-r--r-- | arch/nios2/kernel/setup.c | 2 |
4 files changed, 9 insertions, 4 deletions
diff --git a/arch/nios2/Kconfig.debug b/arch/nios2/Kconfig.debug index 2fd08cbfdddb..55105220370c 100644 --- a/arch/nios2/Kconfig.debug +++ b/arch/nios2/Kconfig.debug @@ -18,7 +18,6 @@ config EARLY_PRINTK bool "Activate early kernel debugging" default y select SERIAL_CORE_CONSOLE - depends on SERIAL_ALTERA_JTAGUART_CONSOLE || SERIAL_ALTERA_UART_CONSOLE help Enable early printk on console This is useful for kernel debugging when your machine crashes very diff --git a/arch/nios2/boot/dts/10m50_devboard.dts b/arch/nios2/boot/dts/10m50_devboard.dts index f362b2224ee7..4bb4dc1b52e9 100644 --- a/arch/nios2/boot/dts/10m50_devboard.dts +++ b/arch/nios2/boot/dts/10m50_devboard.dts @@ -244,6 +244,7 @@ }; chosen { - bootargs = "debug console=ttyS0,115200"; + bootargs = "debug earlycon console=ttyS0,115200"; + stdout-path = &a_16550_uart_0; }; }; diff --git a/arch/nios2/kernel/early_printk.c b/arch/nios2/kernel/early_printk.c index c08e4c1486fc..4a7bb98f744c 100644 --- a/arch/nios2/kernel/early_printk.c +++ b/arch/nios2/kernel/early_printk.c @@ -81,8 +81,11 @@ static void early_console_write(struct console *con, const char *s, unsigned n) } #else -# error Neither SERIAL_ALTERA_JTAGUART_CONSOLE nor SERIAL_ALTERA_UART_CONSOLE \ -selected + +static void early_console_write(struct console *con, const char *s, unsigned n) +{ +} + #endif static struct console early_console_prom = { diff --git a/arch/nios2/kernel/setup.c b/arch/nios2/kernel/setup.c index 6044d9be28b4..8b5146082e3e 100644 --- a/arch/nios2/kernel/setup.c +++ b/arch/nios2/kernel/setup.c @@ -137,6 +137,8 @@ asmlinkage void __init nios2_boot_init(unsigned r4, unsigned r5, unsigned r6, strncpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE); #endif #endif + + parse_early_param(); } void __init setup_arch(char **cmdline_p) |