x86 intel: Add Firmware Interface Table support

Haswell CPUs require a FIT table in the firmware. This commit
adds rudimentary support for a FIT table. The number of entries
in the table is based on a configuration option. The code only
generates a type 0 entry. A follow-on tool will need to be developed
to populate the FIT entries as well as checksumming the table.

Verified image has a FIT pointer and table when option is selected.

Change-Id: I3a314016a09a1cc26bf1fb5d17aa50853d2ef4f8
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/2642
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
diff --git a/src/cpu/intel/Kconfig b/src/cpu/intel/Kconfig
index 45071d0..106ce1d 100644
--- a/src/cpu/intel/Kconfig
+++ b/src/cpu/intel/Kconfig
@@ -33,3 +33,5 @@
 source src/cpu/intel/socket_LGA771/Kconfig
 source src/cpu/intel/socket_LGA775/Kconfig
 source src/cpu/intel/socket_rPGA989/Kconfig
+# Architecture specific features
+source src/cpu/intel/fit/Kconfig
diff --git a/src/cpu/intel/fit/Kconfig b/src/cpu/intel/fit/Kconfig
new file mode 100644
index 0000000..9b57556
--- /dev/null
+++ b/src/cpu/intel/fit/Kconfig
@@ -0,0 +1,12 @@
+config CPU_INTEL_FIRMWARE_INTERFACE_TABLE
+	def_bool n
+	help
+	  This option selects building a Firmware Interface Table (FIT).
+
+config CPU_INTEL_NUM_FIT_ENTRIES
+	int
+	default 4
+	depends on CPU_INTEL_FIRMWARE_INTERFACE_TABLE
+	help
+	  This option selects the number of empty entries in the FIT table.
+
diff --git a/src/cpu/intel/fit/fit.inc b/src/cpu/intel/fit/fit.inc
new file mode 100644
index 0000000..e4595c0
--- /dev/null
+++ b/src/cpu/intel/fit/fit.inc
@@ -0,0 +1,30 @@
+.section ".fit_pointer", "a", @progbits
+	.code32
+.global fit_pointer
+fit_pointer:
+.long fit_table
+.long 0
+.previous
+
+.section ".rom.data", "a", @progbits
+.align 16
+.global fit_table
+.global fit_table_end
+fit_table:
+/* Address for type 0 is '_FIT_   ' */
+.long 0x5449465f
+.long 0x2020205f
+/*
+ * There is 1 entry in the table. Other tools will have to update the size
+ * and checksum when adding entries.
+ */
+.long 0x00000001
+/* Version */
+.word 0x0100
+/* Type 0 with checksum valid. */
+.byte 0x80
+/* Checksum byte - must add to zero. */
+.byte 0x7d
+.fill CONFIG_CPU_INTEL_NUM_FIT_ENTRIES*16
+fit_table_end:
+.previous
diff --git a/src/cpu/intel/fit/fit.lds b/src/cpu/intel/fit/fit.lds
new file mode 100644
index 0000000..9ccfe82
--- /dev/null
+++ b/src/cpu/intel/fit/fit.lds
@@ -0,0 +1,6 @@
+SECTIONS {
+	. = 0xffffffc0;
+	.fit_pointer (.): {
+		*(.fit_pointer)
+	}
+}
diff --git a/src/cpu/intel/haswell/Kconfig b/src/cpu/intel/haswell/Kconfig
index 5b24a8b..460b497 100644
--- a/src/cpu/intel/haswell/Kconfig
+++ b/src/cpu/intel/haswell/Kconfig
@@ -13,6 +13,7 @@
 	select CPU_MICROCODE_IN_CBFS
 	#select AP_IN_SIPI_WAIT
 	select TSC_SYNC_MFENCE
+	select CPU_INTEL_FIRMWARE_INTERFACE_TABLE
 
 config BOOTBLOCK_CPU_INIT
 	string