Extend CMOS POST code logging to store extra data

This can be used to indicate sub-state within a POST
code range which can assist in debugging BIOS hangs.

For example this can be used to indicate which device
is about to be initialized so if the system hangs
while talking to that device it can be identified.

Change-Id: I2f8155155f09fe9e242ebb7204f0b5cba3a1fa1e
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/58104
Reviewed-on: http://review.coreboot.org/4229
Tested-by: build bot (Jenkins)
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>

src/arch/x86/include/bootblock_common.h

@@ -65,6 +65,10 @@ static void cmos_post_init(void)
 		/* Initialize to zero */
 		cmos_write(0, CMOS_POST_BANK_0_OFFSET);
 		cmos_write(0, CMOS_POST_BANK_1_OFFSET);
+#if CONFIG_CMOS_POST_EXTRA
+		cmos_write32(CMOS_POST_BANK_0_EXTRA, 0);
+		cmos_write32(CMOS_POST_BANK_1_EXTRA, 0);
+#endif
 	}
 
 	cmos_write(magic, CMOS_POST_BANK_OFFSET);

src/console/Kconfig

@@ -413,6 +413,14 @@ config CMOS_POST_OFFSET
 	  If CONFIG_HAVE_OPTION_TABLE is enabled then it will use the value
 	  defined in the mainboard option table.
 
+config CMOS_POST_EXTRA
+	bool "Store extra logging info into CMOS"
+	depends on CMOS_POST
+	default n
+	help
+	  This will enable extra logging of work that happens between post
+	  codes into CMOS for debug.  This uses an additional 8 bytes of CMOS.
+
 config IO_POST
 	bool "Send POST codes to an IO port"
 	depends on PC80_SYSTEM

src/console/post.c

@@ -25,6 +25,9 @@
 #include <pc80/mc146818rtc.h>
 #include <smp/spinlock.h>
 #endif
+#if CONFIG_CMOS_POST_EXTRA
+#include <device/device.h>
+#endif
 #include <elog.h>
 
 /* Write POST information */
@@ -51,6 +54,9 @@ DECLARE_SPIN_LOCK(cmos_post_lock)
 void cmos_post_log(void)
 {
 	u8 code = 0;
+#if CONFIG_CMOS_POST_EXTRA
+	u32 extra = 0;
+#endif
 
 	spin_lock(&cmos_post_lock);
 
@@ -58,9 +64,15 @@ void cmos_post_log(void)
 	switch (cmos_read(CMOS_POST_BANK_OFFSET)) {
 	case CMOS_POST_BANK_0_MAGIC:
 		code = cmos_read(CMOS_POST_BANK_1_OFFSET);
+#if CONFIG_CMOS_POST_EXTRA
+		extra = cmos_read32(CMOS_POST_BANK_1_EXTRA);
+#endif
 		break;
 	case CMOS_POST_BANK_1_MAGIC:
 		code = cmos_read(CMOS_POST_BANK_0_OFFSET);
+#if CONFIG_CMOS_POST_EXTRA
+		extra = cmos_read32(CMOS_POST_BANK_0_EXTRA);
+#endif
 		break;
 	}
 
@@ -78,9 +90,31 @@ void cmos_post_log(void)
 		       "in previous boot: 0x%02x\n", code);
 #if CONFIG_ELOG
 		elog_add_event_word(ELOG_TYPE_LAST_POST_CODE, code);
+#if CONFIG_CMOS_POST_EXTRA
+		if (extra)
+			elog_add_event_dword(ELOG_TYPE_POST_EXTRA, extra);
+#endif
 #endif
 	}
 }
+
+#if CONFIG_CMOS_POST_EXTRA
+void post_log_extra(u32 value)
+{
+	spin_lock(&cmos_post_lock);
+
+	switch (cmos_read(CMOS_POST_BANK_OFFSET)) {
+	case CMOS_POST_BANK_0_MAGIC:
+		cmos_write32(CMOS_POST_BANK_0_EXTRA, value);
+		break;
+	case CMOS_POST_BANK_1_MAGIC:
+		cmos_write32(CMOS_POST_BANK_1_EXTRA, value);
+		break;
+	}
+
+	spin_unlock(&cmos_post_lock);
+}
+#endif /* CONFIG_CMOS_POST_EXTRA */
 #endif /* !__PRE_RAM__ */
 
 static void cmos_post_code(u8 value)

src/include/console/console.h

@@ -72,6 +72,11 @@ void console_init(void);
 void console_tx_byte(unsigned char byte);
 void console_tx_flush(void);
 void post_code(u8 value);
+#if CONFIG_CMOS_POST_EXTRA
+void post_log_extra(u32 value);
+#else
+#define post_log_extra(x) do {} while (0)
+#endif
 /* this function is weak and can be overridden by a mainboard function. */
 void mainboard_post(u8 value);
 void __attribute__ ((noreturn)) die(const char *msg);

src/include/elog.h

@@ -140,6 +140,7 @@ struct elog_event_data_me_extended {
 
 /* Last post code from previous boot */
 #define ELOG_TYPE_LAST_POST_CODE          0xa3
+#define ELOG_TYPE_POST_EXTRA              0xa6
 
 /* EC Shutdown Reason */
 #define ELOG_TYPE_EC_SHUTDOWN             0xa5

src/include/pc80/mc146818rtc.h

@@ -202,11 +202,20 @@ static inline enum cb_err get_option(void *dest __attribute__((unused)),
 # endif
 #endif
 
+/*
+ *    0 = Bank Select Magic
+ *    1 = Bank 0 POST
+ *    2 = Bank 1 POST
+ *  3-6 = BANK 0 Extra log
+ * 7-10 = BANK 1 Extra log
+ */
 #define CMOS_POST_BANK_OFFSET     (CMOS_POST_OFFSET)
 #define CMOS_POST_BANK_0_MAGIC    0x80
 #define CMOS_POST_BANK_0_OFFSET   (CMOS_POST_OFFSET + 1)
+#define CMOS_POST_BANK_0_EXTRA    (CMOS_POST_OFFSET + 3)
 #define CMOS_POST_BANK_1_MAGIC    0x81
 #define CMOS_POST_BANK_1_OFFSET   (CMOS_POST_OFFSET + 2)
+#define CMOS_POST_BANK_1_EXTRA    (CMOS_POST_OFFSET + 7)
 
 void cmos_post_log(void);
 #endif /* CONFIG_CMOS_POST */