build rules: Identify build stage with simple variables

Provide simple environment variables telling which stage of boot is
being built. Also move this to arch-agnostic location.

Change-Id: I8cbb5cf91f53e01c06e7d672b5be3f5c235f911d
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/5410
Reviewed-by: Aaron Durbin <adurbin@google.com>
Tested-by: build bot (Jenkins)
diff --git a/src/include/device/device.h b/src/include/device/device.h
index 74bdbd7..dfebeaa 100644
--- a/src/include/device/device.h
+++ b/src/include/device/device.h
@@ -3,7 +3,7 @@
 
 #include <stdint.h>
 #include <stddef.h>
-#include <arch/rules.h>
+#include <rules.h>
 #include <device/resource.h>
 #include <device/path.h>
 
diff --git a/src/include/device/pci.h b/src/include/device/pci.h
index f729c27..5594d29 100644
--- a/src/include/device/pci.h
+++ b/src/include/device/pci.h
@@ -19,7 +19,7 @@
 
 #include <stdint.h>
 #include <stddef.h>
-#include <arch/rules.h>
+#include <rules.h>
 #include <arch/io.h>
 #include <device/pci_def.h>
 #include <device/resource.h>
diff --git a/src/include/device/pnp.h b/src/include/device/pnp.h
index a229edb..43f457b 100644
--- a/src/include/device/pnp.h
+++ b/src/include/device/pnp.h
@@ -2,7 +2,7 @@
 #define DEVICE_PNP_H
 
 #include <stdint.h>
-#include <arch/rules.h>
+#include <rules.h>
 #include <device/device.h>
 #include <device/pnp_def.h>
 
diff --git a/src/include/rules.h b/src/include/rules.h
new file mode 100644
index 0000000..22111e8
--- /dev/null
+++ b/src/include/rules.h
@@ -0,0 +1,63 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef _RULES_H
+#define _RULES_H
+
+/* Useful helpers to tell whether the code is executing in bootblock,
+ * romstage, ramstage or SMM.
+ */
+
+#if defined(__BOOT_BLOCK__)
+#define ENV_BOOTBLOCK 1
+#define ENV_ROMSTAGE 0
+#define ENV_RAMSTAGE 0
+#define ENV_SMM 0
+
+#elif defined(__PRE_RAM__)
+#define ENV_BOOTBLOCK 0
+#define ENV_ROMSTAGE 1
+#define ENV_RAMSTAGE 0
+#define ENV_SMM 0
+
+#elif defined(__SMM__)
+#define ENV_BOOTBLOCK 0
+#define ENV_ROMSTAGE 0
+#define ENV_RAMSTAGE 0
+#define ENV_SMM 1
+#else
+
+#define ENV_BOOTBLOCK 0
+#define ENV_ROMSTAGE 0
+#define ENV_RAMSTAGE 1
+#define ENV_SMM 0
+#endif
+
+/* For romstage and ramstage always build with simple device model, ie.
+ * PCI, PNP and CPU functions operate without use of devicetree.
+ *
+ * For ramstage individual source file may define __SIMPLE_DEVICE__
+ * before including any header files to force that particular source
+ * be built with simple device model.
+ */
+
+#if defined(__PRE_RAM__) || defined(__SMM__)
+#define __SIMPLE_DEVICE__
+#endif
+
+#endif /* _RULES_H */