Add a platform interface

SiFive's pk fork is the second one I've had to maintain, and it's a huge
pain because people keep just leaving changes all over the tree.  I want
to introduce an interface that the platform-specific details can live
behind so I don't have to keep doing these painful merges.

10 files changed, 77 insertions, 1 deletions

diff --git a/bbl/bbl.mk.in b/bbl/bbl.mk.in
index 5abe2cd..e3c5876 100644
--- a/bbl/bbl.mk.in
+++ b/bbl/bbl.mk.in
@@ -3,6 +3,7 @@ bbl_subproject_deps = \
   softfloat \
   machine \
   dummy_payload \
+  platform \
 
 bbl_hdrs = \
   bbl.h \
diff --git a/config.h.in b/config.h.in
index bc6369e..9557930 100644
--- a/config.h.in
+++ b/config.h.in
@@ -40,6 +40,9 @@
 #undef PK_ENABLE_VM
 
 /* Define if subproject MCPPBS_SPROJ_NORM is enabled */
+#undef PLATFORM_ENABLED
+
+/* Define if subproject MCPPBS_SPROJ_NORM is enabled */
 #undef SOFTFLOAT_ENABLED
 
 /* Define to 1 if you have the ANSI C header files. */
diff --git a/configure b/configure
index c1b2b73..25de84d 100755
--- a/configure
+++ b/configure
@@ -4433,6 +4433,51 @@ $as_echo "#define UTIL_ENABLED /**/" >>confdefs.h
 
 
 
+    # Determine if this is a required or an optional subproject
+
+
+
+    # Determine if there is a group with the same name
+
+
+
+    # Create variations of the subproject name suitable for use as a CPP
+    # enabled define, a shell enabled variable, and a shell function
+
+
+
+
+
+
+
+
+
+
+
+    # Add subproject to our running list
+
+    subprojects="$subprojects platform"
+
+    # Process the subproject appropriately. If enabled add it to the
+    # $enabled_subprojects running shell variable, set a
+    # SUBPROJECT_ENABLED C define, and include the appropriate
+    # 'subproject.ac'.
+
+
+      { $as_echo "$as_me:${as_lineno-$LINENO}: configuring default subproject : platform" >&5
+$as_echo "$as_me: configuring default subproject : platform" >&6;}
+      ac_config_files="$ac_config_files platform.mk:platform/platform.mk.in"
+
+      enable_platform_sproj="yes"
+      subprojects_enabled="$subprojects_enabled platform"
+
+$as_echo "#define PLATFORM_ENABLED /**/" >>confdefs.h
+
+
+
+
+
+
   # Output make variables
 
 
@@ -5155,6 +5200,7 @@ do
     "dummy_payload.mk") CONFIG_FILES="$CONFIG_FILES dummy_payload.mk:dummy_payload/dummy_payload.mk.in" ;;
     "machine.mk") CONFIG_FILES="$CONFIG_FILES machine.mk:machine/machine.mk.in" ;;
     "util.mk") CONFIG_FILES="$CONFIG_FILES util.mk:util/util.mk.in" ;;
+    "platform.mk") CONFIG_FILES="$CONFIG_FILES platform.mk:platform/platform.mk.in" ;;
     "config.h") CONFIG_HEADERS="$CONFIG_HEADERS config.h" ;;
     "Makefile") CONFIG_FILES="$CONFIG_FILES Makefile" ;;
 
diff --git a/configure.ac b/configure.ac
index b4a58fd..d4db795 100644
--- a/configure.ac
+++ b/configure.ac
@@ -111,7 +111,7 @@ AC_SUBST(install_subdir)
 # The '*' suffix indicates an optional subproject. The '**' suffix
 # indicates an optional subproject which is also the name of a group.
 
-MCPPBS_SUBPROJECTS([ pk, bbl, softfloat, dummy_payload, machine, util ])
+MCPPBS_SUBPROJECTS([ pk, bbl, softfloat, dummy_payload, machine, util, platform ])
 
 #-------------------------------------------------------------------------
 # MCPPBS subproject groups
diff --git a/machine/machine.mk.in b/machine/machine.mk.in
index cdcb4a7..76e02d9 100644
--- a/machine/machine.mk.in
+++ b/machine/machine.mk.in
@@ -1,5 +1,6 @@
 machine_subproject_deps = \
   softfloat \
+  platform \
 
 machine_hdrs = \
   atomic.h \
diff --git a/pk/pk.mk.in b/pk/pk.mk.in
index 3caa25d..d4be009 100644
--- a/pk/pk.mk.in
+++ b/pk/pk.mk.in
@@ -1,4 +1,5 @@
 pk_subproject_deps = \
+	platform \
 	util \
 	softfloat \
 	machine \
diff --git a/platform/platform.ac b/platform/platform.ac
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/platform/platform.ac
diff --git a/platform/platform.mk.in b/platform/platform.mk.in
new file mode 100644
index 0000000..90ee269
--- /dev/null
+++ b/platform/platform.mk.in
@@ -0,0 +1,9 @@
+platform_subproject_deps =
+
+platform_hdrs = \
+  platform_interface.h
+
+platform_c_srcs = \
+  spike.c
+
+platform_asm_srcs =
diff --git a/platform/platform_interface.h b/platform/platform_interface.h
new file mode 100644
index 0000000..0f49056
--- /dev/null
+++ b/platform/platform_interface.h
@@ -0,0 +1,14 @@
+#ifndef PLATFORM__PLATFORM_H
+#define PLATFORM__PLATFORM_H
+
+/* This interface is designed to allow BBL/PK to be portable to multiple target
+ * platforms.  The current interface has been hacked up based on SiFive's fork
+ * of pk that runs on our FPGA boards.  The idea here is that rather than
+ * forking pk and touching things all over the tree, changes should be local to
+ * the target directory.
+ *
+ * This interface isn't meant to be stable or sane, just better than what we
+ * had before.
+ */
+
+#endif
diff --git a/platform/spike.c b/platform/spike.c
new file mode 100644
index 0000000..9764057
--- /dev/null
+++ b/platform/spike.c
@@ -0,0 +1 @@
+#include "platform_interface.h"