Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) #include <linux/console.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) #include "chan_user.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) /* ----------------------------------------------------------------------------- */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) /* trivial console driver -- simply dump everything to stderr                    */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  * Don't register by default -- as this registers very early in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)  * boot process it becomes the default console.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)  * Initialized at init time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) static int use_stderr_console = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) static void stderr_console_write(struct console *console, const char *string,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 				 unsigned len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 	generic_write(2 /* stderr */, string, len, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) static struct console stderr_console = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 	.name		= "stderr",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	.write		= stderr_console_write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	.flags		= CON_PRINTBUFFER,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) static int __init stderr_console_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	if (use_stderr_console)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 		register_console(&stderr_console);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) console_initcall(stderr_console_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) static int stderr_setup(char *str)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 	if (!str)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 	use_stderr_console = simple_strtoul(str,&str,0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) __setup("stderr=", stderr_setup);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) /* The previous behavior of not unregistering led to /dev/console being
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)  * impossible to open.  My FC5 filesystem started having init die, and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)  * system panicing because of this.  Unregistering causes the real
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)  * console to become the default console, and /dev/console can then be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)  * opened.  Making this an initcall makes this happen late enough that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)  * there is no added value in dumping everything to stderr, and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)  * normal console is good enough to show you all available output.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) static int __init unregister_stderr(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 	unregister_console(&stderr_console);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) __initcall(unregister_stderr);