[U-Boot] [PATCH 1/2] Add board_panic_no_console to deal with early critical errors

[Simon Glass]

Tested-by: Simon Glass <sjg at chromium.org>
Signed-off-by: Simon Glass <sjg at chromium.org>
---
 include/common.h |    8 ++++++++
 lib/vsprintf.c   |   26 ++++++++++++++++++++++++--
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/include/common.h b/include/common.h
index 12a1074..856df9a 100644
--- a/include/common.h
+++ b/include/common.h
@@ -250,6 +250,14 @@ int	last_stage_init(void);
 extern ulong monitor_flash_len;
 int mac_read_from_eeprom(void);
 
+/*
+ * Called during a panic() when no console is available. The board should do
+ * its best to get a message to the user any way it can. This function should
+ * return if it can, in which case the system will either hang or reset.
+ * See panic().
+ */
+void board_panic_no_console(const char *str);
+
 /* common/flash.c */
 void flash_perror (int);
 
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index c029fbb..fd742a9 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -24,6 +24,8 @@
 # define NUM_TYPE long long
 #define noinline __attribute__((noinline))
 
+DECLARE_GLOBAL_DATA_PTR;
+
 const char hex_asc[] = "0123456789abcdef";
 #define hex_asc_lo(x)   hex_asc[((x) & 0x0f)]
 #define hex_asc_hi(x)   hex_asc[((x) & 0xf0) >> 4]
@@ -714,13 +716,33 @@ int sprintf(char * buf, const char *fmt, ...)
 	return i;
 }
 
+/* Provide a default function for when no console is available */
+static void __board_panic_no_console(const char *msg)
+{
+	/* Just return since we can't access the console */
+}
+
+void board_panic_no_console(const char *msg) __attribute__((weak,
+					alias("__board_panic_no_console")));
+
 void panic(const char *fmt, ...)
 {
+	char str[CONFIG_SYS_PBSIZE];
 	va_list	args;
+
 	va_start(args, fmt);
-	vprintf(fmt, args);
-	putc('\n');
+
+	/* TODO)sjg): Move to vsnprintf() when available */
+	vsprintf(str, fmt, args);
 	va_end(args);
+
+	if (gd->have_console) {
+		puts(str);
+		putc('\n');
+	} else {
+		board_panic_no_console(str);
+	}
+
 #if defined (CONFIG_PANIC_HANG)
 	hang();
 #else
-- 
1.7.3.1