lynxpoint: export mem console pointer in ACPI

Instead of having an OS re-parse cbmem book-keeping records
for the cbmem allocator just to get the console buffer export
the pointer to the memory console directly in a field named 'CBMC'.
This field lives in the GNVS table.

Change-Id: Ief0c4da7b18df66feb9c816c9f4abdf5a72bd3a4
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/49764
Reviewed-by: Stefan Reinauer <reinauer@chromium.org>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: http://review.coreboot.org/4149
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/mainboard/google/slippy/acpi_tables.c

@@ -92,6 +92,9 @@ static void acpi_create_gnvs(global_nvs_t *gnvs)
 	gnvs->chromeos.vbt2 = ACTIVE_ECFW_RO;
 #endif
 
+	/* Update the mem console pointer. */
+	gnvs->cbmc = (u32)cbmem_find(CBMEM_ID_CONSOLE);
+
 	acpi_update_thermal_table(gnvs);
 }
 

src/mainboard/intel/baskingridge/acpi_tables.c

@@ -106,6 +106,9 @@ static void acpi_create_gnvs(global_nvs_t *gnvs)
 	gnvs->chromeos.vbt2 = ACTIVE_ECFW_RO;
 #endif
 
+	/* Update the mem console pointer. */
+	gnvs->cbmc = (u32)cbmem_find(CBMEM_ID_CONSOLE);
+
 	acpi_update_thermal_table(gnvs);
 }
 

src/mainboard/intel/wtm2/acpi_tables.c

@@ -103,6 +103,9 @@ static void acpi_create_gnvs(global_nvs_t *gnvs)
 	gnvs->chromeos.vbt2 = ACTIVE_ECFW_RO;
 #endif
 
+	/* Update the mem console pointer. */
+	gnvs->cbmc = (u32)cbmem_find(CBMEM_ID_CONSOLE);
+
 	acpi_update_thermal_table(gnvs);
 }
 

src/southbridge/intel/lynxpoint/acpi/globalnvs.asl

@@ -131,6 +131,9 @@ Field (GNVS, ByteAcc, NoLock, Preserve)
 	S6B1,	32,	// 0x98 - D21:F6 Serial IO UAR1 BAR1
 	S7B1,	32,	// 0x9c - D23:F0 Serial IO SDIO BAR1
 
+	Offset (0xa0),
+	CBMC, 32,	// 0xa0 - coreboot mem console pointer
+
 	/* IGD OpRegion */
 	Offset (0xb4),
 	ASLB,	32,	// 0xb4 - IGD OpRegion Base Address

src/southbridge/intel/lynxpoint/nvs.h

@@ -90,7 +90,8 @@ typedef struct {
 	/* LynxPoint Serial IO device BARs */
 	u32	s0b[8]; /* 0x60 - 0x7f - BAR0 */
 	u32	s1b[8]; /* 0x80 - 0x9f - BAR1 */
-	u8	rsvd6[20];
+	u32	cbmc;   /* 0xa0 - 0xa3 - coreboot memconsole */
+	u8	rsvd6[16];
 	/* IGD OpRegion (not implemented yet) */
 	u32	aslb; /* 0xb4 - IGD OpRegion Base Address */
 	u8	ibtt; /* 0xb8 - IGD boot type */