[platform][pc] get working on legacy 386 PC

-Add support for x86 legacy mode, designed for 386+ instead of pentium+
-Fixup uart driver to support com2
-Stub out PCI driver properly
-Fixup IDE driver to detect legacy disks

project/pc-x86-64-test.mk

@@ -2,8 +2,6 @@
 #
 ARCH := x86
 SUBARCH := x86-64
-TARGET := pc-x86
-MODULES += \
-	app/shell
 
+include project/target/pc.mk
 include project/virtual/test.mk

project/pc-x86-legacy-test.mk

@@ -0,0 +1,6 @@
+# top level project rules for the pc-x86-legacy-test project
+#
+ARCH := x86
+
+include project/target/pc-legacy.mk
+include project/virtual/test.mk

project/pc-x86-test.mk

@@ -1,20 +1,7 @@
 # top level project rules for the pc-x86-test project
 #
-LOCAL_DIR := $(GET_LOCAL_DIR)
-
 ARCH := x86
 SUBARCH := x86-32
-TARGET := pc-x86
-MODULES += \
-	app/shell \
-	app/pcitests
-
-# extra rules to copy the pc-x86.conf file to the build dir
-#$(BUILDDIR)/pc-x86.conf: $(LOCAL_DIR)/pc-x86.conf
-#	@echo copy $< to $@
-#	$(NOECHO)cp $< $@
-
-#EXTRA_BUILDDEPS += $(BUILDDIR)/pc-x86.conf
-#GENERATED += $(BUILDDIR)/pc-x86.conf
 
+include project/target/pc.mk
 include project/virtual/test.mk

project/target/pc-legacy.mk

@@ -0,0 +1,10 @@
+# top level project rules for the pc virtual project
+#
+ARCH ?= x86
+SUBARCH ?= x86-32
+TARGET := pc-x86
+
+CPU ?= legacy
+
+MODULES += \
+	app/shell

project/target/pc.mk

@@ -0,0 +1,8 @@
+# top level project rules for the pc virtual project
+#
+ARCH ?= x86
+SUBARCH ?= x86-32
+TARGET := pc-x86
+MODULES += \
+	app/shell \
+	app/pcitests

project/virtual/test.mk

@@ -8,7 +8,6 @@ MODULES += \
   lib/aes/test \
   lib/cksum \
   lib/debugcommands \
-  lib/libm \
   lib/version \
 
 WITH_CPP_SUPPORT=true