um: Add os_info() for pre-boot information messages
authorMasami Hiramatsu <mhiramat@kernel.org>
Wed, 17 May 2017 17:16:05 +0000 (02:16 +0900)
committerRichard Weinberger <richard@nod.at>
Wed, 5 Jul 2017 21:17:16 +0000 (23:17 +0200)
Add os_info() for printing out pre-boot information
level messages in stderr. The messages via os_info()
are suppressed by "quiet" kernel command line.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
arch/um/include/shared/os.h
arch/um/os-Linux/util.c

index cd1fa97..9e95bce 100644 (file)
@@ -242,6 +242,8 @@ extern void setup_hostinfo(char *buf, int len);
 extern void os_dump_core(void) __attribute__ ((noreturn));
 extern void um_early_printk(const char *s, unsigned int n);
 extern void os_fix_helper_signals(void);
+extern void os_info(const char *fmt, ...)
+       __attribute__ ((format (printf, 1, 2)));
 
 /* time.c */
 extern void os_idle_sleep(unsigned long long nsecs);
index faee55e..c9bad1b 100644 (file)
@@ -13,6 +13,7 @@
 #include <wait.h>
 #include <sys/mman.h>
 #include <sys/utsname.h>
+#include <init.h>
 #include <os.h>
 
 void stack_protections(unsigned long address)
@@ -152,3 +153,27 @@ void um_early_printk(const char *s, unsigned int n)
 {
        printf("%.*s", n, s);
 }
+
+static int quiet_info;
+
+static int __init quiet_cmd_param(char *str, int *add)
+{
+       quiet_info = 1;
+       return 0;
+}
+
+__uml_setup("quiet", quiet_cmd_param,
+"quiet\n"
+"    Turns off information messages during boot.\n\n");
+
+void os_info(const char *fmt, ...)
+{
+       va_list list;
+
+       if (quiet_info)
+               return;
+
+       va_start(list, fmt);
+       vfprintf(stderr, fmt, list);
+       va_end(list);
+}