[PATCH] console: Add option to keep it silent until env is loaded

[Harald Seiler]

Add a config-option which forces the console to stay silent until the
proper environment is loaded from flash.

This is important when the default environment does not silence the
console but no output must be printed when 'silent' is set in the flash
environment.

After the environment from flash is loaded, the console will be
silenced/unsilenced depending on it.  If PRE_CONSOLE_BUFFER is also
used, the buffer will now be flushed if the console should not be
silenced.

Signed-off-by: Harald Seiler <hws at denx.de>
---
 common/Kconfig   | 10 ++++++++++
 common/console.c |  5 +++++
 2 files changed, 15 insertions(+)

diff --git a/common/Kconfig b/common/Kconfig
index fdcf4536d0..506a4d6245 100644
--- a/common/Kconfig
+++ b/common/Kconfig
@@ -120,6 +120,16 @@ config SILENT_CONSOLE_UPDATE_ON_RELOC
 	  (e.g. NAND). This option makes the value of the 'silent'
 	  environment variable take effect at relocation.
 
+config SILENT_CONSOLE_UNTIL_ENV
+	bool "Keep console silent until environment is loaded"
+	depends on SILENT_CONSOLE
+	help
+	  This option makes sure U-Boot will never use the console unless the
+	  environment from flash does not contain the 'silent' variable.  If
+	  set, the console is kept silent until after the environment was
+	  loaded.  Use this in combination with PRE_CONSOLE_BUFFER to print out
+	  earlier messages after loading the environment when allowed.
+
 config PRE_CONSOLE_BUFFER
 	bool "Buffer characters before the console is available"
 	help
diff --git a/common/console.c b/common/console.c
index 0013d183ae..f0f5a9cf80 100644
--- a/common/console.c
+++ b/common/console.c
@@ -893,6 +893,11 @@ static bool console_update_silent(void)
 	if (!IS_ENABLED(CONFIG_SILENT_CONSOLE))
 		return false;
 
+	if (IS_ENABLED(CONFIG_SILENT_CONSOLE_UNTIL_ENV) && !(gd->flags & GD_FLG_ENV_READY)) {
+		gd->flags |= GD_FLG_SILENT;
+		return false;
+	}
+
 	if (env_get("silent")) {
 		gd->flags |= GD_FLG_SILENT;
 		return false;
-- 
2.36.1