[U-Boot] [RFC PATCH 15/22] Add a flag indicating when the serial console is ready

[Simon Glass]

For sandbox we have a fallback console which is used very early during
U-Boot, before serial drivers are available. Rather than try to guess
when to switch to the real one, add a flag so we can be sure. This makes
sure that sandbox can always output a panic() message, for example, and
avoids silent failure (which is very annoying in sandbox).

Signed-off-by: Simon Glass <sjg at chromium.org>
---

 common/console.c                  | 4 ++--
 drivers/serial/serial.c           | 1 +
 include/asm-generic/global_data.h | 1 +
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/common/console.c b/common/console.c
index 5576dfd..898da39 100644
--- a/common/console.c
+++ b/common/console.c
@@ -417,7 +417,7 @@ static inline void print_pre_console_buffer(void) {}
 void putc(const char c)
 {
 #ifdef CONFIG_SANDBOX
-	if (!gd) {
+	if (!gd || !(gd->flags & GD_FLG_SERIAL_READY)) {
 		os_putc(c);
 		return;
 	}
@@ -447,7 +447,7 @@ void putc(const char c)
 void puts(const char *s)
 {
 #ifdef CONFIG_SANDBOX
-	if (!gd) {
+	if (!gd || !(gd->flags & GD_FLG_SERIAL_READY)) {
 		os_puts(s);
 		return;
 	}
diff --git a/drivers/serial/serial.c b/drivers/serial/serial.c
index 803d850..d2eb752 100644
--- a/drivers/serial/serial.c
+++ b/drivers/serial/serial.c
@@ -418,6 +418,7 @@ static struct serial_device *get_current(void)
  */
 int serial_init(void)
 {
+	gd->flags |= GD_FLG_SERIAL_READY;
 	return get_current()->start();
 }
 
diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h
index b3b91d3..f0ea655 100644
--- a/include/asm-generic/global_data.h
+++ b/include/asm-generic/global_data.h
@@ -106,5 +106,6 @@ typedef struct global_data {
 #define GD_FLG_LOGINIT		0x00020	/* Log Buffer has been initialized */
 #define GD_FLG_DISABLE_CONSOLE	0x00040	/* Disable console (in & out)	   */
 #define GD_FLG_ENV_READY	0x00080	/* Env. imported into hash table   */
+#define GD_FLG_SERIAL_READY	0x00100	/* Pre-reloc serial console ready  */
 
 #endif /* __ASM_GENERIC_GBL_DATA_H */
-- 
1.9.1.423.g4596e3a