x86: config option to disable info from decompression of the kernel

This patch allows the disabling of decompression messages during
x86 bootup.

Signed-off-by: Ben Collins <ben.collins@canonical.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 19 insertions, 5 deletions

diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index ac1e31ba4795..14abaa519221 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -16,6 +16,14 @@ config NONPROMISC_DEVMEM
           obviously disasterous, but specific access can be used by people
           debugging the kernel.
 
+config X86_VERBOSE_BOOTUP
+        bool "Enable verbose x86 bootup info messages"
+        default y
+        help
+          Enables the informational output from the decompression stage
+          (e.g. bzImage) of the boot. If you disable this you will still
+          see errors. Disable this if you want silent bootup.
+
 config EARLY_PRINTK
         bool "Early printk" if EMBEDDED
         default y
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index d10e7274e1fc..11629e903aa5 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -202,7 +202,8 @@ static void free(void *where);
 static void *memset(void *s, int c, unsigned n);
 static void *memcpy(void *dest, const void *src, unsigned n);
 
-static void putstr(const char *);
+static void __putstr(int, const char *);
+#define putstr(__x)  __putstr(0, __x)
 
 #ifdef CONFIG_X86_64
 #define memptr long
@@ -266,11 +267,16 @@ static void scroll(void)
                 vidmem[i] = ' ';
 }
 
-static void putstr(const char *s)
+static void __putstr(int error, const char *s)
 {
         int x, y, pos;
         char c;
 
+#ifndef CONFIG_X86_VERBOSE_BOOTUP
+        if (!error)
+                return;
+#endif
+
 #ifdef CONFIG_X86_32
         if (real_mode->screen_info.orig_video_mode == 0 &&
             lines == 0 && cols == 0)
@@ -363,9 +369,9 @@ static void flush_window(void)
 
 static void error(char *x)
 {
-        putstr("\n\n");
-        putstr(x);
-        putstr("\n\n -- System halted");
+        __putstr(1, "\n\n");
+        __putstr(1, x);
+        __putstr(1, "\n\n -- System halted");
 
         while (1)
                 asm("hlt");